XML Schema: Requirements and candidate requirements for version 1.1

Version


Version $Id: reqs.html,v 1.1.2.2 2004/07/15 08:19:23 ht Exp $

This document summarizes the candidate requirements for future versions of XML Schema.

The status of each requirement is recorded in the table. The status may be:

proposed
A new issue (these will typically be unclassified).
todo
An issue that remains to be discussed.
active
The WG is currently discussing the issue. The issue may or may not be classified. See the classification field for further info
roughed
The WG has discussed this and agreed in principle on the technical solution to be used. Draft final wording is to be prepared by the editors.
drafted
The editors have prepared draft final wording for WG approval, but it has not yet been approved.
bounced
The WG has discussed the draft final wording prepared by the editors and has sent it back to the editors for revision.
resolved
The WG has adopted final wording which discharges the issue.
revisit
The WG has discussed this but was unable to reach consensus; we will need to come back to it.
postponed
The WG has discussed this but has set it aside for now. It should come up again, but if it does not, the requirement will not be met in XML Schema 1.1.
overtaken
This item has been overtaken by events and is no longer pertinent. This may be because the requirement refers to or assumes a feature of the spec which has been or will be removed, or because it is subsumed by a more general requirement; in the latter case, there should be a cross reference to that other requirement.
abandoned
The WG has abandoned work on this item; if it is a requirement, it will not be met in version 1.1 of XML Schema; it may be met in other later versions, if any.
ng
This is a non-goal. No further work is expected on it.

The classification of each requirement is recorded in the table. The classification may be:

Unclassified version
WG needs to classify.
Req version
A requirement for that version.
Desideratum version
A desideratum for that version. I.e. we wish to achieve the goal described and will expend time and effort to do so, but we will drop the requirement if it proves too difficult or conflicts with other requirements including our schedule.
Opp Des version
An opportunistic desideratum for that version. We will achieve it if doing so proves easy and straightforward (i.e. if it's low-hanging fruit); we do not expect to expend significant resources to do so.
Non-goal version
A non-goal for that version. This does not necessarily mean that it is a non-goal for future versions.

NumClClusterStatusOriginatorResponsibleDescription
RQ-1 Req Num resolved Henry Zongaro Specify canonical representation of float and double
RQ-2 Req D/T roughed Mark Davis Specify canonical representation of duration
RQ-3 Req D/T postponed I18n WG Address localization issues with date and time types
RQ-4 Req Dat postponed I18n WG Address localization issues with datatypes
RQ-6 Req D/T resolved Kohsuke Kawaguchi Specify unit of length for all primitive types
RQ-7 Req Str roughed Matthew Fuchs Improve interaction between wildcards and substitution groups
RQ-9 Req Str postponed James Clark Expand wildcard namespace constraints
RQ-10 Req Str abandoned Matthew Fuchs Improve interaction between exclusions and disallowed substitutions
RQ-11 Req Restr overtaken Yan Leshinsky Address problems with pointless occurrences rule
RQ-12 Req Restr overtaken Achille Fokoue Resolve choice:choice derivation issues
RQ-13 Req D/T roughed Kohsuke Kawaguchi Time zone normalization crosses date line
RQ-14 Req SCD roughed Mary Holstege Provide schema component for selector/field annotations
RQ-15 Req Restr roughed Khaled Noaman/Henry S. Thompson Correct restriction of identity constraints
RQ-16 Req SCD overtaken Include the identity constraints in the schema component
RQ-17 Req Restr roughed Matthew Fuchs Redo restriction rules
RQ-19 Req SCD roughed XML Schema WG Correctly handle annotations in the PSVI
RQ-20 Desideratum D/T resolved Provide ordered duration types
RQ-21 Desideratum Dat roughed Provide regex or BNF for all primitive types
RQ-22 Desideratum PSVI roughed Add normalized default value for attributes
RQ-23 Desideratum SCD overtaken Dan Connolly First class objects
RQ-24 Desideratum Dat drafted Dave Peterson Systematic treatment of fundamental facets
RQ-25 Non-goal ID ng Interactions with legacy types
RQ-26 Desideratum Str abandoned XML Schema WG Simplify final and block
RQ-28 Opp.Des. Num roughed Mike Cowlishaw Allow scientific notation for decimals
RQ-29 Opp.Des. Str postponed I18N WG Address localization issues in Structures
RQ-30 Opp.Des. Num roughed Mike Cowlishaw Allow negative fractionDigits
RQ-31 Desideratum Num roughed Mike Cowlishaw Provide decimal type that retains trailing zeroes
RQ-32 Opp.Des. Dat abandoned Bob Schloss, Mike McCaleb Allow abstract simple types
RQ-33 Opp.Des. ID todo Jane Hunter (MPEG-7) Add key constraints based on element types
RQ-34 Opp.Des. XSD resolved Add inline schemas
RQ-35 Opp.Des. Str abandoned Improve named model group syntax
RQ-36 Opp.Des. Str revisit Allow local references
RQ-37 Opp.Des. PSVI postponed Provide normalized value for complex/mixed elements
RQ-38 Desideratum Str revisit Add co-constraints
RQ-39 Non-goal D/T ng Michael Anderson Restricting duration
RQ-40 Non-goal D/T ng David RR Webber support non-Gregorian dates
RQ-41 Non-goal D/T ng Ninggang Chen duration is incomplete
RQ-42 Non-goal Str ng I18n WG pattern on mixed content
RQ-43 Non-goal D/T ng I18n WG Locale-dependent datatype support
RQ-44 Non-goal MiPa ng Martin Roberts Allow other list delimiters
RQ-45 Non-goal D/T ng Robert Miller Support for Arrays
RQ-46 Non-goal D/T ng Multiple order relationships
RQ-47 Non-goal D/T ng I18n WG Single lexical representation
RQ-48 Non-goal D/T ng Philipp Niederau Hierarchy Facet
RQ-49 Non-goal Str ng Curt Arnold Schema component binding to the namespace without a name
RQ-50 Non-goal Dat ng Uwe Zeise Run-time parameterization of types
RQ-51 Non-goal XSD ng Patrick Sheppard Dynamic facets
RQ-52 Non-goal XSD ng Support multiple inheritance
RQ-53 Non-goal sfs ng Martin Duerst Order of declarations
RQ-54 Non-goal Str ng Martin Duerst maxOccurs and all group
RQ-55 Non-goal MiPa ng Anders W. Tell Microparsing
RQ-56 Non-goal Str ng Drop nested element declarations
RQ-57 Non-goal Str ng Global Attributes
RQ-58 Non-goal MiPa ng Association of repeated child elements with lists
RQ-59 Non-goal D/T ng Array type refs
RQ-60 Non-goal XSD ng multiple schema languages
RQ-61 Non-goal PSVI ng PSVI as schema input
RQ-62 Non-goal D/T ng Mapping between enumerations
RQ-63 Non-goal D/T ng Restricting unions and lists
RQ-64 Non-goal D/T ng Derivation of Simple Types
RQ-65 Non-goal XML ng Drop notations
RQ-66 Non-goal ID ng Multi-part keys
RQ-67 Non-goal ID ng Multi-doc keys
RQ-68 Non-goal ID ng CMSMCQ Reify symbol spaces
RQ-69 Non-goal ID ng ID constraints and chameleon include
RQ-70 Non-goal XSD ng Paul Grosso Locating Schemas by Public Identifiers
RQ-71 Non-goal XSD ng Curt Arnold Schema locations declared before use
RQ-72 Non-goal Str ng Allow block, default on element refs
RQ-73 Non-goal Str ng Allow derivation of named groups
RQ-74 Non-goal Restr ng Redefine restrictions
RQ-75 Non-goal Str ng I18n WG Merge mixed with string
RQ-76 Non-goal Str ng XML Query WG New method of defining repetition
RQ-77 Non-goal Str ng I18n WG Character Repertoire Restrictions
RQ-78 Non-goal Str ng Element defaults
RQ-79 Non-goal XSD ng XForms WG XForms requirements
RQ-80 Non-goal XSD ng MSM The grammar needs a start symbol.
RQ-81 Non-goal XML ng HTML WG, Jeffrey Yasskin General entities
RQ-82 Non-goal XSD ng Conformance profiles
RQ-83 Non-goal Lang ng Kohsuke Kawaguchi language datatype case sensitivity
RQ-84 Non-goal lib ng I18N WG Type Library for I18N related datatypes
RQ-85 Non-goal XSD ng Canonical form for schema documents
RQ-86 Non-goal D/T ng I18n WG Control characters and localization
RQ-87 Non-goal lib ng Martin Bryan Type Library for Measurements
RQ-88 Non-goal patt ng Named patterns
RQ-89 Non-goal Restr ng Curt Arnold Revise restriction rules
RQ-90 Non-goal QT ng XML Query WG Untyped type
RQ-91 Non-goal ID ng Eric van der Vlist Validating XPointer IDREFS
RQ-92 Non-goal ID ng Mike McCaleb Allow key/keyRef mechanism to augment IDREFs
RQ-93 Non-goal Str ng Forbid numeric exponents on groups
RQ-94 Non-goal Str ng Forbid numeric exponents on named model groups
RQ-95 Non-goal XSD ng Eliminate elements with simple types
RQ-96 Non-goal XSD ng Streaming Processors
RQ-97 Opp.Des. Str postponed Xan Gregg Allow typed wildcards
RQ-98 Non-goal XSD ng Jonathan Robie Deprecate unused language features
RQ-99 Desideratum Str todo Paul. V. Biron Allow an element to be in more than one substitution group
RQ-100 Opp.Des. Lang resolved Ashok Malhotra Canonical form for language
RQ-101 Non-goal PSVI ng Philip Wadler PSVI Representation of Untyped Character Data
RQ-102 Non-goal PSVI ng Henry Thompson PSVI access to e.g. [validation attempted] and [validity]
RQ-103 Non-goal QT ng Noah Mendelsohn Typing of nodes not governed by a schema
RQ-104 Non-goal MiPa ng xiaotaow@cs.columbia.edu User-defined delimiters for lists
RQ-105 Opp.Des. ID abandoned Stefan.Wachter@gmx.de Allow complex types more than one ID attribute
RQ-106 Non-goal QN ng Dan Connolly A QName can have multiple values if bound to more than one URI
RQ-107 Non-goal ver ng dtchang@us.ibm.com Define use of xsi:schemaVersion
RQ-108 Non-goal Dat ng Mark Baker Add URI datatype
RQ-109 Non-goal XSD ng Francois SORIN Allow multiple target namespaces in a Schema
RQ-110 Non-goal ID ng David Parker-Bastable Allow uniqueness based on a function of the value
RQ-111 Non-goal Str ng Robert Brotherus Default element on a choice group
RQ-112 Opp.Des. Dat abandoned ben@jetpen.com Support extensible enumerations
RQ-113 Non-goal Dat ng Paul V. Biron Equivalence comparisons on anyURI
RQ-114 Non-goal D/T ng Rick Jellife Add a anyString datatype as parent of string
RQ-115 Non-goal XSD ng Michael Russ <mruss@edvision.com> Indicate element cannot be root
RQ-116 Non-goal D/T ng Mark Preston <mark@magpiesnest.co.uk> Permit derivation of new atomic types as combination of existing types
RQ-117 Non-goal ID ng Rick Taylor, Michael Gruebsch Allow keys on complex and simple types
RQ-118 Non-goal XSD ng Mark Seaborne, Michael Gruebsch Provide choice groups for attributes
RQ-119 Non-goal XSD ng Douglas and Elena Husemann (husemann@cox-internet.com) Allow vendors to extend XML Schema
RQ-120 Desideratum XSD revisit Berthold Daum Make consistent use of the term "derived"
RQ-121 Req Str roughed Stanley Guan, Ashok Malhotra Clarify behavior for attributes that are both fixed and prohibited
RQ-122 Req D/T active Dave Peterson Define value space for dateTime more precisely
RQ-123 Req D/T roughed Dave Peterson Allow year 0000 in date-related types
RQ-125 Req Str roughed Michael Sperberg-McQueen Clarify identity of anonymous types
RQ-126 Req Dat roughed Dave Peterson Restricting away canonical forms
RQ-128 Opp.Des. Dat abandoned Francois Yergeau Allow an additional value for the whitespace facet called, perhaps, I18N-collapse
RQ-129 Desideratum Dat roughed Xan Gregg Remove dependency on canonical lexical representations
RQ-130 Req SCD roughed Asir Vedamuthu, Mary Holstege Lost annotations
RQ-131 Req SCD roughed Asir Vedamuthu, Mary Holstege Ordering for {annotations} property
RQ-132 Non-goal SCD ng Asir Vedamuthu, Mary Holstege Origin of attribute/model group components
RQ-133 Req SCD overtaken Asir Vedamuthu, Mary Holstege Identity constraints accessibility in component graph
RQ-134 Req SCD roughed Asir Vedamuthu, Mary Holstege Origin of inherited portions of content model
RQ-135 Opp.Des. XSD todo Matthew Fuchs Consistency and validity for a set of schema components
RQ-137 Req XSD roughed Sandy Gao Provide error codes for all violations
RQ-138 Non-goal Str ng Sandy Gao, Asir Vedamuthu Nillable and Fixed are allowed together
RQ-139 Non-goal D/T ng Jim Melton Make anyURI a subtype of string
RQ-140 Req Num drafted XML Schema WG Distinguish negative from positive zero.
RQ-141 Req Dat roughed XML Schema WG Add the abstract datatype anyAtomicType
RQ-142 Req PSVI roughed Lisa Martin Are non-required PSVI properties forbidden?
RQ-143 Req Str todo Richard Tobin Question about assessment outcome for attributes
RQ-144 Req Str active Noah Mendelsohn Which PSVI properties must processors report?
RQ-145 Non-goal Str ng Noah Mendelsohn Add a "value" property for attributes and elements with simple content.
RQ-146 Req Str active David Bau needs clarification re. wildcards
RQ-147 nongoal Str ng Noah Mendelsohn Allow "length" after "min/maxLength", but not the other way around.
RQ-147b Desideratum Str todo Noah Mendelsohn Make "length" specifications set "min/maxLength" facets, not a separate facet.
RQ-148 Req Dat roughed Steven Taschuk Clarify the use of the word "truncation" in lexical forms.
RQ-149 Non-goal Str abandoned Xan Gregg Deprecate use of numeric exponents on model groups
RQ-150 Req Dat roughed John Tebbutt, Ashok Malhotra Problems with minimum number of digits for decimal
RQ-151 Req XSD active Xan Gregg Define schema composition
RQ-152 Unclassified unassigned proposed Henry Thompson, Noah Mendelsohn Should XML Schema be aligned with XML 1.1?
RQ-153 Unclassified unassigned proposed David Ezell Schema 1.1 Namespace

RQ-1 canonical-float: Specify canonical representation of float and double

Locus: datatypes Cluster: Num
Class: Req Status: resolved
Assigned to:
Originator: Henry Zongaro

Description

The canonical representation of float and double must be refined because it currently maps several lexical representations into a single legal value. Specifically, the description of the canonical representation must address (1) signed exponents, and (2) trailing zeroes in the mantissa.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001Mar/0184.html.

Interactions and Input

Input from Straw Poll O-4.

This item was discussed in the meeting of 2004-01-22

This item was discussed in the Cannes face to face meeting of 2004-03-02. Phase 2 wording was amended and approved.

Proposed Resolution

Mail from Ashok Malhotra and subsequent thread (member-only links)

RQ-2 canonical-duration: Specify canonical representation of duration

Locus: datatypes Cluster: D/T
Class: Req Status: roughed
Assigned to:
Originator: Mark Davis

Description

There must be a canonical representation of duration, and a process for calculating the canonical representation from any other lexical representation. Currently, a period of one day and a period of 24 hours are considered two different values in the value space. They should be considered two different lexical representations of the same value.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001Jan/0215.html. See also http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0102.html : R-170.

Interactions and Input

Input from Straw Poll O-5.

Microsoft proposals, item 1.1 (member-only link)

Michael Kay (member-only link)

This item was mentioned in the meeting of 2003-09-18

This item was discussed in the meeting of 2003-10-03

This item was discussed in the meeting of 2004-01-09

This item was discussed in the meeting of 2004-06-11.

RQ-3 datetime-localization: Address localization issues with date and time types

Locus: datatypes Cluster: D/T
Class: Req Status: postponed
Assigned to:
Originator: I18n WG

Description

Address localization concerns regarding the date and time types.

See (member-only link) http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#i18n-datetime : LC-221.

Interactions and Input

Input from Straw Poll O-5.

NOTE 2002-08-02: this needs to be analysed into its constituent items, and each item acted on individually.

RQ-4 localization: Address localization issues with datatypes

Locus: datatypes Cluster: Dat
Class: Req Status: postponed
Assigned to:
Originator: I18n WG

Description

Address localization concerns regarding Part 2: Datatypes.

See (member-only link) http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#i18n-dt-misdirected : LC-207.

Interactions and Input

Input from Straw Poll O-6

NOTE 2002-08-02: this needs to be analysed into its constituent items, and each item acted on individually.

This item was postponed in the meeting of 2004-04-22.

RQ-6 unit-of-length: Specify unit of length for all primitive types

Locus: datatypes Cluster: D/T
Class: Req Status: resolved
Assigned to:
Originator: Kohsuke Kawaguchi

Description

Unit of length must be defined for the all primitive types, including anyURI, QName, and NOTATION.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0391.html.

Interactions and Input

Input from Straw Poll O-7

This item was mentioned in the meeting of 2003-09-18

Actual Resolution

Discussion on the June 19, 2003, telcon established that in the 2e draft, all simple types to which the length facet applies have lengths defined.

RQ-7 wildcards: Improve interaction between wildcards and substitution groups

Locus: structures Cluster: Str
Class: Req Status: roughed
Assigned to:
Originator: Matthew Fuchs

Description

Address problems with the interaction between wildcards and substitution groups. Specifically, resolve the bug where if complex type A has a wildcard, and B restricts A, then it can restrict the wildcard to a set of elements that match the wildcard. Not all elements in the substitution groups of those elements necessarily match the wildcard - so B is not a subset of A.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001Apr/0047.html.

See also http://www.w3.org/2000/12/xmlschema-crcomments.html#x6 : CR-2.

Interactions and Input

Input from Straw Poll O-12

Cf. RQ-135.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-18. All we need to say to discharge this requirement is that restriction is transitive. The types derived by multiple restriction steps should also obey the wildcard. There was some doubt over whether the constructive rules of XML Schema 1.0 achieve this, but the definition of restriction in section 2 seems to entail it.

Actual Resolution

RESOLVED: our phase 1 agreement on RQ-007 is that it appears to be taken care of by the existing constructive rules. Phase 2 approval will be established by our accepting a proof that this is so.

In leaving the topic, MSM remarked that if we discharge requirement RQ-017 correctly, RQ-007 should follow automatically.

RQ-9 wildcard-ns-sets: Expand wildcard namespace constraints

Locus: structures Cluster: Str
Class: Req Status: postponed
Assigned to:
Originator: James Clark

Description

The namespace constraints on wildcards must be more expressive in order to be able to express the union or intersection of any two wildcards. Specifically, it must be possible to express "any namespace except those in the following list."

See http://www.w3.org/2000/12/xmlschema-crcomments.html#wildcard-minus : CR-20.

See also http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0164.html.

Interactions and Input

Input from:

James Clark: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0216

Judith A. Slein: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0050

Matthew Fuchs: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0052

Judith A. Slein: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0053

Matthew Fuchs: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0054

Judith A. Slein: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0057

Straw Poll O-12

This item was discussed in the meeting of 2003-11-04

This item was postponed in the meeting of 2004-05-13. It may be taken up again in the context of the discussion of how best to support versioning.

Proposed Resolution

Microsoft proposals, item 1.3 (member-only link)

Asir Vedamuthu(member-only link)

RQ-10 substitution-groups: Improve interaction between exclusions and disallowed substitutions

Locus: structures Cluster: Str
Class: Req Status: abandoned
Assigned to:
Originator: Matthew Fuchs

Description

Improve interaction between substitution group exclusions and disallowed substitutions in the element component.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001Apr/0049.html.

Interactions and Input

Input from Straw Poll O-12

This item was abandoned in the meeting of 2004-05-13.

RQ-11 pointless-occs: Address problems with pointless occurrences rule

Locus: structures Cluster: Restr
Class: Req Status: overtaken
Assigned to:
Originator: Yan Leshinsky

Description

Revise the derivation of complex-type restriction so as to eliminate the problems with pointless occurrences. Currently, it eliminates some derivations that should otherwise be valid.

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfipointless : R-24.

Interactions and Input

Input from Straw Poll O-14

This item was discussed in the meeting of 2004-04-09.

This item was closed in the meeting of 2004-05-13. It has been overtaken by events: if RQ-17 succeeds, this has no referent in the spec.

Proposed Resolution

Microsoft proposals, item 1.2 (member-only link)

RQ-12 choice-vs-choice: Resolve choice:choice derivation issues

Locus: structures Cluster: Restr
Class: Req Status: overtaken
Assigned to:
Originator: Achille Fokoue

Description

Revise the particle derivation rules so as to eliminate the problems with choice/choice rules.

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfichoicechoice : R-42.

Interactions and Input

Input from Straw Poll O-14

This item was closed in the meeting of 2004-05-13. It has been overtaken by events: if RQ-17 succeeds, this has no referent in the spec.

RQ-13 time: Time zone normalization crosses date line

Locus: datatypes Cluster: D/T
Class: Req Status: roughed
Assigned to:
Originator: Kohsuke Kawaguchi

Description

Resolve the issue that relates to timezone normalization resulting in a time crossing over the date line.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0366.html.

Interactions and Input

Input from :

Straw Poll O-5

This item was discussed in the meeting of 2003-09-05

This item was discussed in the meeting of 2003-09-11

This item was discussed in the meeting of 2003-09-17

This item was discussed in the meeting of 2003-09-26

This item was discussed in the meeting of 2003-10-02

This item was discussed in the meeting of 2003-11-03

RQ-14 id-inconsistency: Provide schema component for selector/field annotations

Locus: structures Cluster: SCD
Class: Req Status: roughed
Assigned to:
Originator: Mary Holstege

Description

The XML representation for field and selector allows an annotation, but there is no schema component to which this annotation can adhere. This inconsistency must be resolved.

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfiIdConstrAnnot : R-46.

Interactions and Input

Input from Straw Poll O-10

Proposed Resolution

Henry Thompson, proposing a resolution for RQ-14, RQ-19, RQ-130 and RQ-131.

RQ-15 id-restriction: Correct restriction of identity constraints

Locus: structures Cluster: Restr
Class: Req Status: roughed
Assigned to:
Originator: Khaled Noaman/Henry S. Thompson

Description

Resolve the issues associated with restricting types whose elements include identity constraints. Specifically, (1) the rule must changed to state that the restricted type must have a superset rather than a subset of identity constraints, (2) the term superset must be clearly defined, and (3) there must be a way to redefine identity constraints in the restricted type without causing duplicate name problems.

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfiIdConsRestrict : R-94.

Interactions and Input

Input from Straw Poll O-10

Interacts with RQ-17.

This item was discussed in the meeting of 2004-04-09. We agreed that we would like to see the proposal written down. The minutes say “The description in the minutes may suffice as written proposal; if not, HT will write it up. Others to say if the minutes are insufficient.”

Further action is needed.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-05-13.

RQ-16 id-components: Include the identity constraints in the schema component

Locus: structures Cluster: SCD
Class: Req Status: overtaken
Assigned to:
Originator:

Description

Add an [identity constraints] property of the schema component, which contains all the identity constraint components, just as the [type definitions] property contains all the type definition components.

Interactions and Input

Input from Straw Poll O-10

NOTE 2002-08-02: this item is unclear to the members of the WG present at the August 2002 face to face meeting; a clearer statement of the intended requirement is needed.

Clarified by Henry.

This item was mentioned in the meeting of 2003-09-18

This item was closed in the meeting of 2003-11-04. The issue has been classified as an erratum (R-105) and does not need to be taken care of as part of 1.1. Cf. also RQ-133.

RQ-17 restrictn-rules: Redo restriction rules

Locus: structures Cluster: Restr
Class: Req Status: roughed
Assigned to:
Originator: Matthew Fuchs

Description

Remove the current rules on derivation by restriction; define legal restrictions in terms of their effect on the language, not in terms of a structural relationship between the base type and the derived type.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-wg/2001May/0018.html.

Interactions and Input

Input from Straw Poll O-14

Interacts with several other requirements; proposals for this requirement also cover or affect RQ-11, RQ-12, RQ-15, RQ-146.

Confirmed as Requirement at 2002-08-02 F2F. We discussed reclassifying it and decided not to.

This item was discussed in the meeting of 2003-11-04

This item was discussed in the meeting of 2004-04-09.

This item was discussed in the meeting of 2004-04-15.

This item was discussed in the meeting of 2004-05-06.

This item was discussed in the meeting of 2004-05-07.

This item was discussed in the meeting of 2004-05-12.

This item was discussed in the meeting of 2004-05-20.

This item was discussed in the meeting of 2004-06-04.

RQ-19 annotation-psvi: Correctly handle annotations in the PSVI

Locus: structures Cluster: SCD
Class: Req Status: roughed
Assigned to:
Originator: XML Schema WG

Description

Systematise and correct the handling of annotations and out-of-bound attributes in the PSVI.

Interactions and Input

Input from Straw Poll O-15

This item was discussed in the meeting of 2003-11-04

This item was discussed in the meeting of 2003-11-21; Noah Mendelsohn to draft a phase-1 proposal (making sure that foreign-namespace attributes are not lost).

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-18.

Proposed Resolution

Henry Thompson, proposing a resolution for RQ-14, RQ-19, RQ-130 and RQ-131.

RQ-20 ordered-duration: Provide ordered duration types

Locus: datatypes Cluster: D/T
Class: Desideratum Status: resolved
Assigned to:
Originator:

Description

Provide totally ordered duration types, specifically one that is expressed only in years and months, and one that is expressed only in days, hours, minutes, and seconds (ignoring leap seconds.) Possibly define other totally ordered duration types such as day/hour/minute and hour/minute/second duration.

Interactions and Input

Input from Straw Poll O-5

This item was discussed in the meeting of 2003-09-17

This item was mentioned in the meeting of 2003-09-18

This item was discussed in the meeting of 2003-10-03

This item was discussed (and phase-1 agreement reached) in the meeting of 2003-10-09

This item was discussed in the meeting of 2003-10-10. The draft wording was returned to the editors for revision.

This item was discussed in the meeting of 2003-11-03

This item was discussed in the meeting of 2003-12-04; the editors submitted revised text that day.

This item was discussed and phase 2 wording was considered, amended, and approved in the meeting of 2003-12-18.

This item was discussed in the meeting of 2004-01-09.

This item was discussed in the meeting of 2004-06-11.

Proposed Resolution

yearMonthDuration and dayTimeDuration as defined in XQuery and XPath Function and Operators

RQ-21 bnf: Provide regex or BNF for all primitive types

Locus: datatypes Cluster: Dat
Class: Desideratum Status: roughed
Assigned to:
Originator:

Description

Provide regular expressions or BNF productions to express (1) the valid lexical representations and (2) the canonical lexical representation of each primitive built-in type.

Interactions and Input

Input from Straw Poll O-7

This item was mentioned in the meeting of 2003-09-18

This item was discussed in the meeting of 2003-10-10

This item was discussed in the meeting of 2003-10-16

This item was discussed in the meeting of 2003-11-04. We agreed that yes, we will have BNF and/or regular expressions and that this constitutes agreement for phase 1. Details of the BNF and regexes are to be considered in phase 2.

This item was discussed in the meeting of 2004-01-09

This item was discussed in the meeting of 2004-04-29. The WG noted that we were (already) done with phase 1 agreement.

Proposed Resolution

Alexander Falk (member-only link)

RQ-22 norm-default: Add normalized default value for attributes

Locus: structures Cluster: PSVI
Class: Desideratum Status: roughed
Assigned to:
Originator:

Description

Add a [normalized value] property to the constructed attribute infoitem which arises when a default value is applied.

Interactions and Input

Input from Straw Poll O-15

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-04-22.

RQ-23 first-class-obj: First class objects

Locus: structures Cluster: SCD
Class: Desideratum Status: overtaken
Assigned to:
Originator: Dan Connolly

Description

Define an algorithm for generating a URI for any construct in a schema (or, possibly, in a schema document), thus making schema constructs first-class objects in the Web. Minimally the algorithm should cover element( type)s, attributes, simple types, complex types, and notations. Optionally it may also cover other constructs such as named groups and items in enumerations of legal values.

* URIs for terms: motivation [was Requirement Document] Dan Connolly (Fri, Feb 08 2002) http://lists.w3.org/Archives/Public/www-webont-wg/2002Feb/0028.html

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0025.html.

Interactions and Input

Input from Straw Poll O-16

This item was closed (because overtaken by events) in the meeting of 2004-04-23. It remains a requirement for the work of the Working Group, but it will be met by the Schema Component Designators draft, not by XML Schema 1.1. So it does not need to be tracked in this requirements list.

RQ-24 fundamentals: Systematic treatment of fundamental facets

Locus: datatypes Cluster: Dat
Class: Desideratum Status: drafted
Assigned to:
Originator: Dave Peterson

Description

Make the treatment of fundamental facets more systematic. Define canonical forms for all types, and specify the rules for generating the canonical form, given a value. Clarify the status of anySimpleType and define its value space (if any). Clarify the assignment of types to nodes in the absence of relevant schema components. Distinguish our identity relation from the mathematical relation of quantitative equality.

Interactions and Input

Input from Straw Poll O-7

Retained as desideratum 2 August 2002; this is important.

This item was discussed in the meeting of 2003-08-29

This item was discussed in the meeting of 2003-10-23

This item was discussed in the meeting of 2003-10-30

This item was discussed in the meeting of 2003-10-31

This item was discussed in the meeting of 2003-11-04

This item was discussed in the meeting of 2004-05-12.

This item was discussed in the meeting of 2004-05-27.

This item was discussed in the meeting of 2004-06-03.

This item was discussed in the meeting of 2004-06-11. (N.B. the available draft covers part but not all of the substance of our phase-1 agreement.)

Proposed Resolution

Dave Peterson (member-only link)

RQ-25 legacies: Interactions with legacy types

Locus: datatypes Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Interaction between uniqueness and referential integrity constraints on legacy types and union types.

See http://www.w3.org/2000/12/xmlschema-crcomments.html#idrefinunion : CR-50 (broken link).

Example, <simpleType name="referenceType"> <union memberTypes="IDREF uriReference mpeg7:xPathType"/> </simpleType> WG did not consider this issue. Also, "requiring enforcement of the uniqueness constraint would involve arbitrary lookahead before allowing a processor to know what type a value has"

Interactions and Input

Input from Straw Poll O-10

NOTE 2002-08-02: the meaning of this item is unclear to the members of the WG present at the August 2002 face to face; it needs to be clarified and either retained or dropped.

This item was reclassified as a non-goal in the meeting of 2004-03-18.

RQ-26 final-and-block: Simplify final and block

Locus: structures Cluster: Str
Class: Desideratum Status: abandoned
Assigned to:
Originator: XML Schema WG

Description

Eliminate or simplify the interactions between final and block.

Interactions and Input

Input from Straw Poll O-12

This item was abandoned in the meeting of 2004-05-13.

RQ-28 scientific-notn: Allow scientific notation for decimals

Locus: datatypes Cluster: Num
Class: Opp.Des. Status: roughed
Assigned to:
Originator: Mike Cowlishaw

Description

Allow scientific notation for decimals.

See http://www.w3.org/2000/12/xmlschema-crcomments.html#scientific-decimals : CR-23.

Interactions and Input

Our comment of http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0298 : March 2001: "There is sentiment in the WG towards allowing some form of exponential notation for decimals in future, but it would be explicit in instances (e.g. value="3E-10"), not implicit in type definitions."

Input from Straw Poll O-4

This item was discussed in the meeting of 2004-04-01. Phase 1 discussion was closed, because this item will succeed or fail with RQ-031.

RQ-29 localization2: Address localization issues in Structures

Locus: structures Cluster: Str
Class: Opp.Des. Status: postponed
Assigned to:
Originator: I18N WG

Description

Address localization concerns regarding Part 1: Structures.

NOTE: This needs to be analysed into its constituent items, and each item acted on individually.

See (member-only link) http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#i18n-str-misdirected : LC-206.

Interactions and Input

Input from Straw Poll O-16

This item was postponed in the meeting of 2004-04-30.

RQ-30 negative-scale: Allow negative fractionDigits

Locus: datatypes Cluster: Num
Class: Opp.Des. Status: roughed
Assigned to:
Originator: Mike Cowlishaw

Description

Allow negative values for the fractionDigits facet.

See http://www.w3.org/2000/12/xmlschema-crcomments.html#negative-scale : CR-22.

Interactions and Input

Input from Straw Poll O-4

This item was discussed in the meeting of 2004-04-01. Phase 1 discussion was closed, because this item will succeed or fail with RQ-031.

RQ-31 trailing-zeroes: Provide decimal type that retains trailing zeroes

Locus: datatypes Cluster: Num
Class: Desideratum Status: roughed
Assigned to:
Originator: Mike Cowlishaw

Description

Provide a datatype which retains trailing zeroes in the lexical representation of decimal numbers. More generally, provide a precision decimal type, in which each value is associated not only with a magnitude but also with a precision.

See http://www.w3.org/2000/12/xmlschema-crcomments.html#canonical-decimals : CR-42.

Interactions and Input

Input from Straw Poll O-4

Interacts with RQ-28, RQ-30 (the same proposal discharges all).

Changed to desideratum on telcon 2002-11-21. The rationale was that we already have a well developed proposal for this.

This item was discussed in the meeting of 2004-03-02

This item was discussed in the meeting of 2004-04-01. We reached phase-1 agreement on canonical forms and keeping a single NaN.

This item was discussed in the meeting of 2004-05-12. A proposal to reclassify it as a non-goal was discussed briefly, and postponed until late June.

Proposed Resolution

Dave Peterson and Mike Cowlishaw (member-only link)

Latest from Dave Peterson (member-only link)

RQ-32 abstract-simples: Allow abstract simple types

Locus: datatypes Cluster: Dat
Class: Opp.Des. Status: abandoned
Assigned to:
Originator: Bob Schloss, Mike McCaleb

Description

Allow abstract simple types.

See http://www.w3.org/2000/12/xmlschema-crcomments.html#abstract-simples : CR-47.

One way to resolve it would be to return to the system of abstract simple types we had in a working draft, and to resolve the issues we encountered with it. These include:

  • getting both abstract and concrete simple types into the type hierarchy

  • possibly rewording rules on restriction to make it produce the expected results with a hierarchy of both abstract and concrete types

  • making more explicit the role of the mapping from lexical form to value in the constitution of a simple type

  • providing hooks to allow explicit definition of the mapping from lexical space to value space

Interactions and Input

Input from Straw Poll O-7

NOTE 2002-08-02: there was some support for demoting this to a non-goal, on the grounds that it was too hard to get right for 1.1 and it would be better to wait and do it right in 2.0. The idea did not achieve consensus; some members of the WG believed they could define an abstract simple type mechanism which would achieve consensus in the WG.

This item was abandoned in the meeting of 2004-04-22. Three kinds of abstract simple types had been discussed: (a) an abstract numeric type from which the other numerics could be derived, (b) our old (pre-1.0) design for a complete hierarchy of abstract simple types, and (c) user ability to specify abstract = "true" for simple types, as can be done for complex types. It was clear in this meeting that there was no proposal on the table that commanded anything like consensus in the Working Group.

Proposed Resolution

Dave Peterson (member-only link)

Microsoft proposals, item 2.2 (member-only link)

RQ-33 keys-constraints: Add key constraints based on element types

Locus: structures Cluster: ID
Class: Opp.Des. Status: todo
Assigned to:
Originator: Jane Hunter (MPEG-7)

Description

Key constraints to restrict which element types can be pointed to: Allow a schema author use key constaints to specify that a value (which otherwise behaves like an SGML or XML ID) is restricted to pointing at one (or more) particular element type(s)?

See (member-only link) http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#typed-refs : LC-151.

Interactions and Input

Input from Straw Poll O-10

Discussion at http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0127.html

http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0129.html

http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0131.html

RQ-34 inline-schema: Add inline schemas

Locus: structures Cluster: XSD
Class: Opp.Des. Status: resolved
Assigned to:
Originator:

Description

Specify a manner in which schema documents can be included in-line in instances.

See (member-only link) http://www.w3.org/XML/Group/xmlschema-current/issues.html#inlineSchemaInfo : Issue 42.

Interactions and Input

Input from Straw Poll O-11

NOTE 2002-08-02: there was some support at our face to face meeting for promoting this to desideratum, and some for removing it, and some for handling it as a clarification with erratum for XML Schema 1.0 Second Edition; there was most support for leaving it as an opportunistic desideratum. In the absence of consensus to move it, we left it alone. There was speculation that if we get good text for this, the WG might be willing to put it into 2E anyway.

This item was resolved in the meeting of 2004-03-18, with the observation that it is already possible to use inline schemas and that a task force is working on the area.

RQ-35 named-groups: Improve named model group syntax

Locus: structures Cluster: Str
Class: Opp.Des. Status: abandoned
Assigned to:
Originator:

Description

Clean up named model group syntax and component.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0339.html.

See also http://www.w3.org/2000/12/xmlschema-crcomments.html#named-model-groups : CR-32, http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0379.html : [Noah]

Interactions and Input

Input from Straw Poll O-11

NOTE 2002-08-02: there was some sentiment at our face to face meeting for demoting this to a non-goal, but there was not consensus.

This item was abandoned in the meeting of 2004-03-25. The consensus of the WG was that we should make no change here; some attribute this view to compatibility reasons, others to other reasons. The current status quo does in any case match what several commentators said was an acceptable fallback when the issue was discussed in 2000.

RQ-36 local-references: Allow local references

Locus: structures Cluster: Str
Class: Opp.Des. Status: revisit
Assigned to:
Originator:

Description

Change the XML representation (and possibly the component structure) of local element declarations to at least allow, if not require, all particles to be references, with scope, i.e. put the local declarations directly under <complexType>

(Cf. no-nesting).

Interactions and Input

This is subsumed proposals to deal with R-17.

Input from Straw Poll O-15

This item was postponed in the meeting of 2004-04-30. It will stand or fall with the ‘landscape’ proposal for RQ-017 and friends. If that proposal succeeds, this requirement will be discharged; if not, we are unlikely to do this on its own.

This item was discussed in the meeting of 2004-05-20.

Proposed Resolution

Asir Vedamuthu (member-only link)

RQ-37 norm-value: Provide normalized value for complex/mixed elements

Locus: structures Cluster: PSVI
Class: Opp.Des. Status: postponed
Assigned to:
Originator:

Description

Provide a [schema normalized value] for all valid element infoitems, not just those of simple type, and address the question of typing the characters in mixed content.

Interactions and Input

Input from Straw Poll O-15

This item was postponed in the meeting of 2004-03-25.

This item was taken up again and discussed in the face to face meeting of 2004-05-13 but there was no consensus on the proposal. The item was again postponed.

RQ-38 coconstraints: Add co-constraints

Locus: structures Cluster: Str
Class: Desideratum Status: revisit
Assigned to:
Originator:

Description

Add the ability to define and enforce co-constraints on attribute values, or on attribute values and sub-elements. For example, if attribute a has value foo, the attribute b must have one of the values fuzz, duz, or buzz; but if attribute a has value bar, the attribute b must have one of the values car, far, or tar. Or: if attribute href occurs, the element must be empty; if it does not occur, then it must have type phrase-level-content.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0040.html : LC-193 Response.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001AprJun/0175.html : R-7 in Errata List.

Interactions and Input

This issue was also formerly known as co-occurrence (RQ-27; removed)

Input from Straw Poll O-13

Opportunistic desideratum for 1.1: At our meeting in August 2002, some members of the WG felt that co-constraints needed to be a requirement for 1.1, others that the feature is too complex to design in the time available and with the compatibility constraints agreed for 1.1. Some WG members thought an 80/20 solution would be easy to specify, and undertook to demonstrate this by doing so.

This item was abandoned in the meeting of 2004-03-25.

A request to reopen it was was received on 25 May from Fabio Vitali (member-only link).

RQ-39 patterned-durati: Restricting duration

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Michael Anderson

Description

Can a schema author constrain values of the time-duration type to be measured only or at most in days?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#duration-restricting : LC-103.

Interactions and Input

Input from Straw Poll O-5

RQ-40 non-gregorian: support non-Gregorian dates

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: David RR Webber

Description

support non-Gregorian dates

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#non-gregorian-dates : LC-21.

Interactions and Input

Input from Straw Poll O-5

RQ-41 timeduration: duration is incomplete

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Ninggang Chen

Description

duration is incomplete per ISO 8601, because it provides no way to identify start or end point of the duration.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#pt2-durations : LC-120.

Interactions and Input

Input from Straw Poll O-5

RQ-42 mixed-patterns: pattern on mixed content

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Allow a pattern facet on complex types with content='mixed', so as to allow control over the character repertoire allowed in the character content of elements witha particular complex type?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#complexpattern : LC-217.

Interactions and Input

Input from Straw Poll O-6

RQ-43 loc-independence: Locale-dependent datatype support

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Take steps to support the definition of locale-dependent datatypes (i.e., datatypes with locale-specific lexical spaces)?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#mlr : LC-219.

Interactions and Input

Input from Straw Poll O-6

RQ-44 list-delimiters: Allow other list delimiters

Locus: datatypes Cluster: MiPa
Class: Non-goal Status: ng
Assigned to:
Originator: Martin Roberts

Description

Allow schema authors to provide list delimiters other than white space?

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0261 : List types.

Interactions and Input

Input from Straw Poll O-8

RQ-45 arrays: Support for Arrays

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Robert Miller

Description

Should XML Schema be modified to provide support for arrays?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#arrays : LC-84.

Interactions and Input

Input from Straw Poll O-8

RQ-46 multiple-orders: Multiple order relationships

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Should it be possible for ordered datatypes to have multiple (user-defined?) order relations?

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#multipleOrders : Issue 108.

Interactions and Input

Input from Straw Poll O-8

RQ-47 single-lex: Single lexical representation

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Single lexical representation for each built-in type: Modify XML Schema so that each built-in type has only a single legal lexical representation for each value in its value space?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#SLR : LC-220.

Interactions and Input

Input from Straw Poll O-9

RQ-48 hierarchy: Hierarchy Facet

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Philipp Niederau

Description

Add a new hierarchy facet to simplify definitions which would otherwise require complex regular expressions or verbose enumerations?

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0338 : Hierarchy constraining facets)

and http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0372 : Meaning of block="substitution"?

Interactions and Input

Input from Straw Poll O-9

RQ-49 unqualified-bits: Schema component binding to the namespace without a name

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: Curt Arnold

Description

Change the method of binding schema components to the namespace without a name and using them to validate unqualified elements in a document.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#undeclared-ns : LC-89

Interactions and Input

Input from Straw Poll O-11

RQ-50 run-time-parm: Run-time parameterization of types

Locus: structures Cluster: Dat
Class: Non-goal Status: ng
Assigned to:
Originator: Uwe Zeise

Description

Allow the run-time parameterization of types.

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfiRuntimeTypes : R-7

Interactions and Input

Input from :

Straw Poll O-13

RQ-51 dynamic-facets: Dynamic facets

Locus: datatypes Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Patrick Sheppard

Description

Dynamic specification of maxOccurs: Allow maxOccurs and other schema information to be specified dynamically in the document instance?

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000OctDec/0310

Interactions and Input

Input from Straw Poll O-13

RQ-52 multiple-inher: Support multiple inheritance

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Support multiple inheritance.

Interactions and Input

Input from Straw Poll O-14

RQ-53 attdecl-order: Order of declarations

Locus: structures Cluster: sfs
Class: Non-goal Status: ng
Assigned to:
Originator: Martin Duerst

Description

Should XML Schema drop the current requirement that in the declaration of a complex type, the attribute declarations should follow the content-model declaration (if any)?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#attribute-ghetto : LC-190

and http://www.w3.org/2000/12/xmlschema-crcomments.html#pfiOrderCMAtt : CR-4

Also, mail from James Clark.

Interactions and Input

Input from Straw Poll O-15

RQ-54 maxOccurs-all: maxOccurs and all group

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: Martin Duerst

Description

Relationship of all and maxOccurs: Should the all group allow occurrence indicators with maxOccurs > 1?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#all-with-n-gt-1 : LC-16

and http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#all-grp : LC-132

Interactions and Input

Input from Straw Poll O-15

RQ-55 abstract-models: Microparsing

Locus: datatypes Cluster: MiPa
Class: Non-goal Status: ng
Assigned to:
Originator: Anders W. Tell

Description

Should XML Schema be modified to allow the definition of abstract information models together with rules for encoding the information either as elements or strings (for use as attribute values)?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#microparsing : LC-102

Interactions and Input

Input from Straw Poll O-15

RQ-56 no-nesting: Drop nested element declarations

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Remove support for nested element declarations.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#dropNestedElementTypeDecl : Issue 29

Interactions and Input

Input from Straw Poll O-15

RQ-57 global-atts: Global Attributes

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

The namespace REC effectively creates a category of global attributes. We can't at the moment define such things, and their use in an instance would ipso facto render it schema-invalid.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#globalAttrs : Issue 26

Interactions and Input

Input from Straw Poll O-15

RQ-58 lists-children: Association of repeated child elements with lists

Locus: structures Cluster: MiPa
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow the association of repeated child elements in a content model with lists (and possibly ordered sets).

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#collections : Issue 108

and related: http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#set-vs-seq : LC 200

Interactions and Input

Input from Straw Poll O-16

RQ-59 arrays-type-refs: Array type refs

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow arrays of the type and references to type once a type is defined. [?]

See http://lists.w3.org/Archives/Member/w3c-xml-schema-wg/2001May/0039.html : [Martin Gudgin]

Interactions and Input

Input from Straw Poll O-16

RQ-60 multiple-langs: multiple schema languages

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow support for multiple schema languages. Allow more than one schema language; design a framework to allow them to fit together.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#multSchemaLangs : Issue 41

Interactions and Input

Input from Straw Poll O-16

RQ-61 psvi-input: PSVI as schema input

Locus: structures Cluster: PSVI
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

What happens if the input to the schema processor is a PSVI?

See http://www.w3.org/2000/12/xmlschema-crcomments.html#x3 : CR-59

Interactions and Input

Input from Straw Poll O-16

RQ-62 enumeration-maps: Mapping between enumerations

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Mapping between enumeration, Lexical labels for dataypes. Offline list of enumerations.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#enumerationMapping : Issue 111

and http://www.w3.org/XML/Group/xmlschema-current/issues.html#labelEnum : Issue 200

Interactions and Input

Input from Straw Poll O-8

RQ-63 restrict-unions: Restricting unions and lists

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow restrictions of unions and lists in obvious ways, e.g. by restricting the itemType or by subsetting memberTypes (with or without further restriction of the member types)

Interactions and Input

Input from Straw Poll O-8

RQ-64 simple-deriv: Derivation of Simple Types

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

We would like better mechanisms for deriving simple types. For some months we worked with abstract types that allowed derivation of value spaces which could then be linked with lexical spaces but were unable to make this work. While revising the date/time types Mark Davis wanted to derive date from dateTime by restricting its lexical space by a pattern. This is difficult but important.

Interactions and Input

Input from Straw Poll O-9

RQ-65 drop-notations: Drop notations

Locus: datatypes Cluster: XML
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Remove NOTATION declarations, ENTITY and NOTATION datatypes

See http://www.w3.org/2000/12/xmlschema-crcomments.html#entities-and-nottions : CR-17

Interactions and Input

Input from Straw Poll O-9

RQ-66 chained-keyrefs: Multi-part keys

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Provide support for multi-part keys; fix the problems they now have.

Interactions and Input

Input from Straw Poll O-10

RQ-67 multidoc-keys: Multi-doc keys

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Support key references across document boundaries. Identified as a post-1.0 issue by the Working Group.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#xdoc-keyref : LC-201

Interactions and Input

Input from Straw Poll O-10

RQ-68 reify-symbols: Reify symbol spaces

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator: CMSMCQ

Description

Reify symbol spaces.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#reifySymspaces : Issue 123

Interactions and Input

Input from Straw Poll O-10

RQ-69 chameleon-id: ID constraints and chameleon include

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

make it practicable to define identity constraints in schema documents intended for use with chameleon include

See http://www.w3.org/2001/05/xmlschema-rec-comments#pfiIdConstInclude : R-77

Interactions and Input

Input from Straw Poll O-10

RQ-70 locating-schemas: Locating Schemas by Public Identifiers

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Paul Grosso

Description

Locating Schemas by Public Identifiers. Great deal of mail.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-wg/2001Feb/0038 : Paul Grosso

Interactions and Input

Input from Straw Poll O-11

Proposed Resolution

Microsoft proposals, item 3.1 (member-only link)

RQ-71 decl-before-use: Schema locations declared before use

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Curt Arnold

Description

Should XML Schema require that schema locations be declared before or above the elements which claim validity according to the schema in question?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#retro-schemaloc : LC-116

Interactions and Input

Input from Straw Poll O-11

RQ-72 block-use: Allow block, default on element refs

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow block, default, etc., on element uses (i.e. refs), rather than only on declarations.

Interactions and Input

Input from Straw Poll O-12

RQ-73 group-derivation: Allow derivation of named groups

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow derivation of named groups.

Interactions and Input

Input from Straw Poll O-14

RQ-74 redef-restrict: Redefine restrictions

Locus: structures Cluster: Restr
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow the equivalent of restriction in redefining attribute/model groups.

Interactions and Input

Input from Straw Poll O-14

RQ-75 mixed-string-etc: Merge mixed with string

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Merge the notions of mixed content without child elements, textOnly content, and the simple type string

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#dropstring : LC-216

Interactions and Input

Input from Straw Poll O-15

RQ-76 repetition: New method of defining repetition

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: XML Query WG

Description

Modify XML Schema at the transfer syntax level, the abstract level, or both, to define separate element types for repetition (occurence) indications, instead of using the minOccurs and maxOccurs attributes on both element elements and groups?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#repetition-element : LC-222

Interactions and Input

Input from Straw Poll O-15

RQ-77 char-repertoires: Character Repertoire Restrictions

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Support for character repertoire restrictions on mixed content (simple types, regex patterns, schema normalized - default value, etc.)

See http://www.w3.org/2000/12/xmlschema-crcomments.html#mixed-content-norm : CR-26

Interactions and Input

Input from Straw Poll O-15

I18N WG position: We are very unhappy about the XML Schema WG's position on this matter. We have provided many use cases and consider this to be a very significant requirement. We request a commitment to include this capability in Schema 1.1.", http://lists.w3.org/Archives/Member/w3c-xml-schema-wg/2001Mar/0040 : "The XML Schema WG agreed to place this feature on the list of candidate requirements for XML Schema 1.1."

RQ-78 elem-defaults: Element defaults

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Eliminate defaults on elements, or make them more similar to attribute defaults (how?).

Interactions and Input

Input from Straw Poll O-15

RQ-79 xforms: XForms requirements

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: XForms WG

Description

Do whatever is needed to support the subsetting needs and requirements of XForms.

Interactions and Input

Input from Straw Poll O-16

RQ-80 start-symbol: The grammar needs a start symbol.

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: MSM

Description

The grammar needs a start symbol.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#startSymbol : Issue 126

Interactions and Input

Input from Straw Poll O-16

RQ-81 general-entities: General entities

Locus: structures Cluster: XML
Class: Non-goal Status: ng
Assigned to:
Originator: HTML WG, Jeffrey Yasskin

Description

Support declaration of general entities to represent special characters: Extend XML Schema to support the declaration of general entities (or at least of entities which represent special characters, e.g. eacute? Reply to commentator suggested this as a version 2.0 issue.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#character-entities : LC-91

See also http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0016.html

Interactions and Input

Input from Straw Poll O-16

RQ-82 profiles: Conformance profiles

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Define a set of named conformance profiles for XML Schema, to simplify discussions of what capabilities schema processors provide and what requirements particular users have. For example, such named profiles might provide terminology for describing whether a schema processor always starts validation at the document element or at some other node or allows user specification of where to start; what rules a processor follows for constructing the schema against which to validate (and whether they are under user control); whether a processor validates the entire subtree when it finds a processContents=lax, or only the top layer of children, or something else; etc.

RQ-83 language-code: language datatype case sensitivity

Locus: datatypes Cluster: Lang
Class: Non-goal Status: ng
Assigned to:
Originator: Kohsuke Kawaguchi

Description

Address language datatype case sensitivity issues.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2001JanMar/0390.html

Interactions and Input

Input from Straw Poll O-6

Non-goal for 1.1: the only quick solution (magic) is ad hoc; a full solution for specifying case-folding of strings is complex and would take too long to be feasible for 1.1, even if there were consensus in the WG and community that it would be desirable, which there is not.

RQ-84 type-library: Type Library for I18N related datatypes

Locus: datatypes Cluster: lib
Class: Non-goal Status: ng
Assigned to:
Originator: I18N WG

Description

Work with I18N WG to create a common library of I18N related datatypes.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#addins : LC-215

Interactions and Input

Input from Straw Poll O-6

Non-goal for 1.1: the type library is a separate work item, not part of XML Schema 1.1. (Note that some members of the WG do believe it should be integrated into 2.0, but there is not now consensus on this point.)

RQ-85 canonical-form: Canonical form for schema documents

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

define a canonical XML form for schema documents, or optionally for schemas (including multiple-namespace schemas). Such a canonical form would simplify the generation of URIs for arbitrary constructs and would thus help make schema constructs first-class objects in the Web.

Interactions and Input

Input from Straw Poll O-16

Non-goal for 1.1: as a consequence of our discussion of the PSVI on 1 August 2002, the WG decided on 2 August 2002 to treat the proposal for a canonical form for schema documents or schemas as a non-goal for XML Schema 1.1. This topic will continue to be discussed as part of our work on use cases for access to the post-schema-validation information set.

RQ-86 control-chars: Control characters and localization

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: I18n WG

Description

Localization issues with occurrence of control characters: Modify XML Schema to address problems related to the occurrence, in existing systems, of control characters within data.

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#C0 : LC-218

Interactions and Input

Input from Straw Poll O-6

Non-goal for 1.1: it may be useful to define a special element for signaling control characters (analogous to the math-character element for special mathematical characters) and to place it in the type library. Some members of the WG felt that a special mechanism for handling legacy data did not belong in the specification of a schema language.

RQ-87 measurements: Type Library for Measurements

Locus: datatypes Cluster: lib
Class: Non-goal Status: ng
Assigned to:
Originator: Martin Bryan

Description

If measurements are not included as valid XML datatypes they will need to be defined as such by other organizations. Each such organization will invent its own mechanism for this and these will not interwork. This negates the concept of XML being a universal data interchange format.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000JulSep/0238.html

See also http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1036.html

Interactions and Input

Input from Straw Poll O-8

Non-goal for 1.1: this is really a desideratum for the type library, not for XML Schema 1.1.

RQ-88 named-patterns: Named patterns

Locus: datatypes Cluster: patt
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Allow for named patterns and pattern-name references, without recursion.

Interactions and Input

Input from Straw Poll O-9

Non-goal for 1.1: some WG members suggested that this item would require a new component type, and if so that it would be too big a change for 1.1. Some WG members would like it to be a non-goal for 2.0 as well. Some dissent.

RQ-89 restriction: Revise restriction rules

Locus: structures Cluster: Restr
Class: Non-goal Status: ng
Assigned to:
Originator: Curt Arnold

Description

Revise method of restricting complex types: Should the mechanism for restricting complex types be revised to make it less verbose and awkward?

See http://www.w3.org/XML/Group/xmlschema-current/lcissues.html#restriction-awkward : LC-49

Interactions and Input

Input from Straw Poll O-14

Non-goal for 1.1: this is redundant with restrictn-rules.

RQ-90 untyped-type: Untyped type

Locus: structures Cluster: QT
Class: Non-goal Status: ng
Assigned to:
Originator: XML Query WG

Description

Add a type which will be assigned to character data in the absence of an explicit type, regardless of whether it is contained in an element with no children or an attribute, and regardless of whether strict, lax, or skip validation is being attempted. Some WG members feel that this would allow the XML Query type system to be simpler.

It is a goal that this type be expressible as a concrete type in XML text, as is the current anySimpleType:

<foo xsi:type="anySimpleType">abcde</foo>

To make it easier to distinguish whether lax, skip, or strict validation was performed on a node, a separate property could be introduced to the PSVI.

Interactions and Input

Input from Straw Poll O-16

Non-goal for 1.1: this appears no longer to be a desideratum on the part of the Query WG. And we have a desideratum to clarify the value space of anySimpleType, which should achieve most of the advantages hoped for from this item.

RQ-91 xpointer-idrefs: Validating XPointer IDREFS

Locus: datatypes Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator: Eric van der Vlist

Description

Validating XPointer IDREFS

See http://www.w3.org/2000/12/xmlschema-crcomments.html#validating-idrefs : CR-18

Interactions and Input

Input from Straw Poll O-8

Non-goal for 1.1: We decided on 2 August 2002 to make this a non-goal for 1.1. Two inconsistent rationales were given: this is out of scope, and this is in scope but too hard to solve for 1.1.

RQ-92 key-ref-id-ref: Allow key/keyRef mechanism to augment IDREFs

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator: Mike McCaleb

Description

Allow key/keyRef mechanism to augment IDREFs

See http://www.w3.org/2000/12/xmlschema-crcomments.html#keyrefs-idrefs : CR-46

Interactions and Input

Input from Straw Poll O-10

Non-goal for 1.1: We decided 2 August 2002 to make this a non-goal for XML Schema 1.1, on the grounds that we don't know how to solve it now (and thus it's not feasible to solve it for 1.1).

RQ-93 num-grp: Forbid numeric exponents on groups

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Forbid numeric exponents on groups

Interactions and Input

Input from Straw Poll O-15

Non-goal for 1.1: We decided 2 August 2002 to make this a non-goal for XML Schema 1.1, on the grounds that though it is important, it does not appear urgent and may represent too large a change for 1.1.

RQ-94 num-named-grp: Forbid numeric exponents on named model groups

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Forbid numeric exponents on named model groups.

Interactions and Input

Input from Straw Poll O-15

Non-goal for 1.1: We decided 2 August 2002 to make this a non-goal for XML Schema 1.1, on the grounds that though it is important, it does not appear urgent and may represent too large a change for 1.1.

RQ-95 no-simple-elem: Eliminate elements with simple types

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Eliminate elements with simple types, so that <x:element name="foo" type="x:string"/> becomes shorthand for an element with complex type with simple content. (Thus all elements have a complex type, and all attributes have a simple type, and vice versa.)

Interactions and Input

Non-goal for 1.1: We decided 2 August 2002 to make this a non-goal: it raises compatibility issues, may break security applications (?), would be difficult to do in a way that generates consensus, and seems likely to be a significant bug-source if rushed. Some strong sentiment for revisiting this for 2.0.

RQ-96 streamers: Streaming Processors

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator:

Description

Streaming Processors. Conformance section of structural spec seems to preclude stream-based processors.

See http://www.w3.org/XML/Group/xmlschema-current/issues.html#streamingProcs : Issue 44

Interactions and Input

Input from Straw Poll O-16

Non-goal for 1.1: we decided 2 August 2002 to make this a non-goal, with two incompatible rationales: (1) it is a desirable goal but not achievable in 1.1, and (2) there is nothing in 1.0 which in fact precludes streaming processors.

RQ-97 typed-wildcards: Allow typed wildcards

Locus: structures Cluster: Str
Class: Opp.Des. Status: postponed
Assigned to:
Originator: Xan Gregg

Description

Allow a wildcard to indicate that it will allow any element that conforms to a specified type.

Seehttp://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1137.html.

See also http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Sep/0094.html

Interactions and Input

This item was discussed in the meeting of 2004-05-12; there was no consensus, the WG being equally divided between the desire to adopt the proposal and the desire to abandon the desideratum. We agreed to postpone further discussion; the topic may come up again. If it proves useful in supporting versioning, there is a higher likelihood of adoption.

Proposed Resolution

Xan Gregg (member-only link)

RQ-98 deprecate-unused: Deprecate unused language features

Locus: both Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Jonathan Robie

Description

(N.B. nongoal for 1.1, but requirement for 2.0)

XML Schema 1.1 will define a language that is implemented compatibly across at least 3 XML Schema processors. Features that are not part of this interoperable language will be deprecated in XML Schema 1.1.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Aug/0020.html

RQ-99 mult-subs-grps: Allow an element to be in more than one substitution group

Locus: structures Cluster: Str
Class: Desideratum Status: todo
Assigned to:
Originator: Paul. V. Biron

Description

Allow an element declaration to be in more than one substitution group.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-wg/2002Sep/0016.html.

RQ-100 canon-language: Canonical form for language

Locus: datatypes Cluster: Lang
Class: Opp.Des. Status: resolved
Assigned to:
Originator: Ashok Malhotra

Description

We need a canonical form for the language datatype. Both upper and lower case variants are permitted.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Mar/0036.html

Interactions and Input

This item was discussed in the meeting of 2003-11-21

Actual Resolution

The definition of the language datatype has been changed in 2e to permit only those lexical forms allowed by RFC 3066.

RQ-101 psvi-untyped: PSVI Representation of Untyped Character Data

Locus: structures Cluster: PSVI
Class: Non-goal Status: ng
Assigned to:
Originator: Philip Wadler

Description

PSVI Representation of Untyped Character Data.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Feb/0151.html

RQ-102 psvi-access: PSVI access to e.g. [validation attempted] and [validity]

Locus: structures Cluster: PSVI
Class: Non-goal Status: ng
Assigned to:
Originator: Henry Thompson

Description

>PSVI access to e.g. [validation attempted] and [validity].

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Feb/0004.html

RQ-103 type-no-schema: Typing of nodes not governed by a schema

Locus: structures Cluster: QT
Class: Non-goal Status: ng
Assigned to:
Originator: Noah Mendelsohn

Description

Typing of nodes not governed by a schema.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001Dec/0020.html

RQ-104 list-delim: User-defined delimiters for lists

Locus: datatypes Cluster: MiPa
Class: Non-goal Status: ng
Assigned to:
Originator: xiaotaow@cs.columbia.edu

Description

User-defined delimiters for lists.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0103.html

RQ-105 multiple-id: Allow complex types more than one ID attribute

Locus: structures Cluster: ID
Class: Opp.Des. Status: abandoned
Assigned to:
Originator: Stefan.Wachter@gmx.de

Description

Relax the constraint that a complex type may contain at most one attribute of type ID.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0069.html.

Interactions and Input

Henry argues IDs are legacy and we should allow only one ID value per element. Thus, outlaw list of ID, attribute and child element having ID vales.

This item was abandoned in the meeting of 2004-04-30.

Proposed Resolution

Henry Thompson. (member-only link)

On the Nov 14, 2003 telcon we decided that lists of IDs were allowed but would not serve as identifiers in the sense that an ID attribute does. Ashok Malhotra to draft note.

RQ-106 qname-ambiguous: A QName can have multiple values if bound to more than one URI

Locus: datatypes Cluster: QN
Class: Non-goal Status: ng
Assigned to:
Originator: Dan Connolly

Description

A QName can have multiple values if bound to more than one URI. Suggest that the lexical form of QNames should be considered to include the relevant namespace name; that'll make it unambiguous.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0056.html

RQ-107 schema-version: Define use of xsi:schemaVersion

Locus: structures Cluster: ver
Class: Non-goal Status: ng
Assigned to:
Originator: dtchang@us.ibm.com

Description

Define use of xsi:schemaVersion.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0116.html

RQ-108 new-uri-type: Add URI datatype

Locus: datatypes Cluster: Dat
Class: Non-goal Status: ng
Assigned to:
Originator: Mark Baker

Description

Add a "URI" type that allows only a URI, not a URI reference. The current anyURI type allows a URI reference.

(since a URI identifies a resource, whereas a URI reference identifies some chunk of data - they are very different things).

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1141.html.

Interactions and Input

This item was discussed in the meeting of 2003-11-04. It's a non-goal: users who want only URIs, not URI references, can define their own subtype in the obvious way.

This item was mentioned in the meeting of 2003-09-18

RQ-109 multi-target-ns: Allow multiple target namespaces in a Schema

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Francois SORIN

Description

Would like to define small part of one XML Schema document with one target namespace another part with different target namespace. It's very useful if we can also redefine or redirect a namespace for more flexibility.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1139.html.

RQ-110 unique-function: Allow uniqueness based on a function of the value

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator: David Parker-Bastable

Description

It would be useful to be able to constrain uniqueness based on the {upper-case/other string function} of the value of an element or attribute, say by allowing the field to be an XPath expression such as upper-case(@NAME).

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1135.html.

RQ-111 default-choice: Default element on a choice group

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: Robert Brotherus

Description

Wants a default element on a choice group.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1134.html.

RQ-112 extensible-enum: Support extensible enumerations

Locus: datatypes Cluster: Dat
Class: Opp.Des. Status: abandoned
Assigned to:
Originator: ben@jetpen.com

Description

Support for extensible enumerations such as allowed in Java.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1130.html.

Interactions and Input

This item was discussed in the meeting of 2003-11-04

This item was in the meeting of 2004-04-29.

This item was abandoned in the meeting of 2004-05-12.

RQ-113 canon-uri: Equivalence comparisons on anyURI

Locus: datatypes Cluster: Dat
Class: Non-goal Status: ng
Assigned to:
Originator: Paul V. Biron

Description

We fail to say how equiv comparisons are performed on anyURI (e.g., for checking a literal against an enumeration). I'd also note that we don't say anything of this kind about a lot of types (string, etc.). We rely on phrases like "if the {value} is in the value space...".

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1100.html.

Interactions and Input

This item was discussed in the meeting of 2003-11-04

This item was classified as Non-goal in the meeting of 2004-03-11. The WG's reasoning was that this is subsumed by R-132 and doesn't need to be a separate requirement.

This item was discussed in the meeting of 2004-04-22.

RQ-114 anyString: Add a anyString datatype as parent of string

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Rick Jellife

Description

There needs to be a change in the type hierarchy to introduce anyString before String where anyString allows any characters (except 0x00) in Unicode except surrogates (by definition) and has a facet transmissionEncoding ( plain | bin64 | bin16 | q ) "plain" which expresses the lexical form of the data being sent.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1138.html.

RQ-115 cannot-be-root: Indicate element cannot be root

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Michael Russ <mruss@edvision.com>

Description

Add attribute on top-level element declarations to indicate that such an element cannot be the document root.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0153.html.

RQ-116 combine-atomic: Permit derivation of new atomic types as combination of existing types

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Mark Preston <mark@magpiesnest.co.uk>

Description

One of the major things missing from version 1 is the ability to define new atomic types as a combination of existing types. As an example, the construction of a "currency" type that might consist of the two simple atomic types:

eg. currencycode: string, restricted to "#", "$" etc.

currencyval : decimal, 2 fractional digits

-> currency : union of: currencycode and currencyval

So, this new atomic type would permit values such as #27.20 and $7.01 but would reject both "#" and "15.88" and "15.1" etc.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0131.html.

RQ-117 complex-keys: Allow keys on complex and simple types

Locus: structures Cluster: ID
Class: Non-goal Status: ng
Assigned to:
Originator: Rick Taylor, Michael Gruebsch

Description

Non-goal for 1.1, but possible requirement for 2.0

Allow the definition of constraints (key, keyref, unique) on <xs:complexType> <xs:simpleType> to recycle them among different locally defined elements or among elements structural identical but with different names.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1120.html and http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0092.html.

RQ-118 attr-choice: Provide choice groups for attributes

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Mark Seaborne, Michael Gruebsch

Description

(class: subsumed)

Allow choice groups to include attributes. By this the following use cases could be covered:

  • allow only certain combinations of attributes resp. attribute groups. Example: Allow either the definition of an attribute name or a reference to an element:

    <A id="x" name="some.name"/> <A idref="x"/> Compare this to the content model of XLink attributes where only certain attribute combinations are allowed.

  • make it possible to allow only certain combinations between attributes and elements

    Example: Reference to an element which is out of scope <A id="x" a="5"/> <B idref="x"/> can be used *instead of* a local element <B> <A a="5"/> </B> Compare this to the definition of the XML W3C Schema where <xsd:element> either refer to a global definition or is defined locally.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0001.html.

and http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JanMar/1121.html.

Interactions and Input

This item was classified as a non-goal in the meeting of 2004-03-11

This item was abandoned in the meeting of 2004-03-25.

RQ-119 extensiblity: Allow vendors to extend XML Schema

Locus: structures Cluster: XSD
Class: Non-goal Status: ng
Assigned to:
Originator: Douglas and Elena Husemann (husemann@cox-internet.com)

Description

Allow vendors to extend XML Schema.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002AprJun/0009.html.

RQ-120 term-derived: Make consistent use of the term "derived"

Locus: both Cluster: XSD
Class: Desideratum Status: revisit
Assigned to:
Originator: Berthold Daum

Description

XML Schema Part 1 (Structure) and XML Schema Part 2 (Datatypes) have different notions of "derived" for simple types, specifically with regard to list and union types.

According to Part1, setion 3.14.6, Schema Component Constraint: Type Derivation OK (Simple), type unions and list extensions are NOT "derived" from their respective member types (but their member types are regarded as "derived" from the union type resp. list extension). (Also R-170)

This is in contrast to Part 2, which defines union types and list extensions as "derived" from their respective member types (2.5.2.2 and 2.4.2.3).

The inconsistent semantics of "derived" can lead to confusion among schema authors, in particular when working with substituion groups, instance type overriding, and redefinitions.

We suggest to drop the term "derived" for type unions and list extensions in XML Schema Part 2 and to replace it with the term "constructed". This would also affect the classification of the built-in types NMTOKENS, IDREFS, and ENTITIES, which are no longer "derived by list" but "constructed by list".

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0014.html.

Ashok's response: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0022.html.

Interactions and Input

This item was discussed in the meeting of 2004-04-30. We did not achieve consensus on instructions to the editors.

Proposed Resolution

Berthold Daum

RQ-121 prohibited-and-fixed: Clarify behavior for attributes that are both fixed and prohibited

Locus: structures Cluster: Str
Class: Req Status: roughed
Assigned to:
Originator: Stanley Guan, Ashok Malhotra

Description

Clarify the expected processor behavior if an attribute has both use="prohibited", and a fixed value specified.

Should a schema validator:

  1. silently ignore fixed, or

  2. flag "attribute fixed and prohibited" as an error

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Sep/0122.html.

Interactions and Input

This item was discussed in the meeting of 2003-10-24

This item was discussed in the meeting of 2003-11-21. Let prohibited win? Treat as error on component? Handle symmetrically with type? Need to make sure we handle possible re-introduction of attributes prohibited in the base. Need a phase-1 proposal.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-25.

RQ-122 dateTime-values: Define value space for dateTime more precisely

Locus: datatypes Cluster: D/T
Class: Req Status: active
Assigned to:
Originator: Dave Peterson

Description

The definition of the dateTime value space does not reference a part of ISO 8601 that defines dateTime values, only lexical representations. The reference should be corrected, and the recommendation should explain or fix the fuzziness and/or gaps in the definitions referenced.

Dave P: "In 3.2.7 we assert that "the value space of dateTime is the space of Conbinations of date and time of day values as defined in [Clause] 5.4 of ISO 8601". I notice also that Clause 5 of 8601 is titled "Representations" and the first sentence of Clause 5.4 asserts "a time-point can be identified through a combination of date and time of the day representations provided for in this International Standard". From this, I conclude our reference is at best incorrect, since the referenced text only addresses standardized lexical representations."

"It is clear from our discussions that we do not equate dateTime values with lexical representations thereof; the mapping is not 1-1."

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0258.html.

Interactions and Input

Dave Peterson (member-only link)

Approved for addition in Chapel Hill: http://www.w3.org/XML/2002/10/xml-schema-ftf-minutes#xs11.3111

This may have been solved by accepting Dave Peterson's proposal for R-120 erratum for R-120 (member-only link)

This item was discussed in the meeting of 2003-09-17

This item was discussed in the meeting of 2004-03-01

Proposed Resolution

Dave Peterson erratum for R-120 (member-only link)

RQ-123 year-zero: Allow year 0000 in date-related types

Locus: datatypes Cluster: D/T
Class: Req Status: roughed
Assigned to:
Originator: Dave Peterson

Description

The year 0000 should be allowed in the types date, dateTime, gYear and gYearMonth.

In the 1998 version of ISO 8601 the year 0000 was prohibited. This was changed in the 2000 version. We have received mail from James Clark and others that this should be corrected.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0258.html.

Interactions and Input

Approved for addition in Chapel Hill: http://www.w3.org/XML/2002/10/xml-schema-ftf-minutes#xs11.3111.

This may have been solved by accepting the erratum for R-120 (member-only link) which includes a note about allowing year 0000.

This item was mentioned in the meeting of 2003-09-18

Proposed Resolution

Dave Peterson erratum for R-120 (member-only link)

RQ-125 id-anon-types: Clarify identity of anonymous types

Locus: structures Cluster: Str
Class: Req Status: roughed
Assigned to:
Originator: Michael Sperberg-McQueen

Description

We need to be clear where the XML Schema spec depends on component identity. We need a language to talk about identity of types, in general, and particularly with respect to anonymous types. Can an inherited type have an anonymous type? Are anonymous types that appear multiple types in a model group the same type?

See (member-only link) minutes of 10/24 telcon.

Interactions and Input

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-05-13.

RQ-126 restrict-can-forms: Restricting away canonical forms

Locus: datatypes Cluster: Dat
Class: Req Status: roughed
Assigned to:
Originator: Dave Peterson

Description

Pattern derivations remove lexical representations directly from the lexical space. If a lexical representation is not unique then it is possible with a pattern to remove the canonical representation without removing all representations, thereby leaving the value in the value space but without a canonical representation. This is related to RQ-129.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0186.html.

Interactions and Input

This item was discussed in the meeting of 2003-11-21. Paul Biron to produce phase-1 proposal.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-19.

Proposed Resolution

Dave Peterson and subsequent thread (member-only links)

RQ-128 new-whitespace-value: Allow an additional value for the whitespace facet called, perhaps, I18N-collapse

Locus: datatypes Cluster: Dat
Class: Opp.Des. Status: abandoned
Assigned to:
Originator: Francois Yergeau

Description

Our Hong Kong minutes also contain "we request the Schema WG to accept as a requirement the need for a new value of the whiteSpace facet (strawman: "i18n-collapse"), which would specify i18n-correct whitespace normalization along the lines of XHTML Mod." This would be for those who would have misused "replace" or "collapse" as a way to perform pretty-printing unwrapping. It would do the Right Thing in this context, taking into account the scripts on both sides of the white space to be collapsed as outlined by Michel's detailed conformance clause. I am not personally convinced that Schema is the right place to put such functionality, but the proposal is there and I think the Schema WG is best placed to assess it appropriateness.

See (member-only link) http://lists.w3.org/Archives/Member/w3c-i18n-wg/2001Oct/0032.

Interactions and Input

This item was classified as Opp.Des. in the meeting of 2004-04-29.

This item was in the meeting of 2004-04-29.

This item was abandoned in the meeting of 2004-05-12.

RQ-129 eliminate-canonical: Remove dependency on canonical lexical representations

Locus: datatypes Cluster: Dat
Class: Desideratum Status: roughed
Assigned to:
Originator: Xan Gregg

Description

Dependencies of schema processing on canonical lexical representations should be removed. This will eliminate the need for processors to ever produce a canonical representation, for example for a default value. This will also address RQ-126.

Rewrite Structures to eliminate dependency on canonical forms.

See thread starting at http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Dec/0079.html.

[N.B. the requirement is not, as sometimes paraphrased, to make canonical lexical representations non-normative, but to remove dependencies on them.]

Interactions and Input

This item was discussed in the meeting of 2003-11-04

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-19.

RQ-130 scd-lost-annotation: Lost annotations

Locus: structures Cluster: SCD
Class: Req Status: roughed
Assigned to:
Originator: Asir Vedamuthu, Mary Holstege

Description

In 2 cases, some of the annotations are lost.

  1. The enumeration and pattern facets have a single {annotation} property, but they collapse multiple enumeration and pattern elements, each of which may have its own annotation.

  2. The schema-as-a-whole component defines the {annotations} property by reference to the [children] of single schema element II.

See http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002OctDec/0000.

See also http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0222.html .

Interactions and Input

On July 25 telcon agreed to add commets that resulted in R-163 to this issue. See material from R-163 copied below:

The Schema for Schemas and the Rec should be consistent wrt where annotations are allowed. The Schema for Schemas permits an annotation on any element/attribute element, but the Rec is missing annotation information for some schema component definitions.

Henry Thompson

as well as an earlier posting with an example: David Stephenson

This item was discussed in the meeting of 2003-11-21

This item was classified as Req in the meeting of 2004-03-11.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-26.

Proposed Resolution

Henry Thompson, proposing a resolution for RQ-14, RQ-19, RQ-130 and RQ-131.

RQ-131 scd-ordering-annotation: Ordering for {annotations} property

Locus: structures Cluster: SCD
Class: Req Status: roughed
Assigned to:
Originator: Asir Vedamuthu, Mary Holstege

Description

No intrinsic ordering or other distinguishable property for annotations. Where annotations are promoted or otherwise coalesced from multiple elements, there is no means to distinguish them, and therefore reference them with a SCD.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0222.html.

See also http://www.w3.org/TR/2003/WD-xmlschema-ref-20030109/#issue_annotation_predicate.

Interactions and Input

This item was classified as Req in the meeting of 2004-03-11.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-26.

Proposed Resolution

Henry Thompson, proposing a resolution for RQ-14, RQ-19, RQ-130 and RQ-131.

RQ-132 scd-origin-groups: Origin of attribute/model group components

Locus: structures Cluster: SCD
Class: Non-goal Status: ng
Assigned to:
Originator: Asir Vedamuthu, Mary Holstege

Description

Today, there is no mechanism to trace back the origin of some of the components that were assembled via compiling an attribute/model group. Model groups and attribute groups get unrolled at the point of use in a way that leaves no trace in the component model. The same schema components therefore recur in the graph in undetectable ways. Given that the named model and attribute groups exist in their own right as schema components, this is at least inconsistent with how, say, type or attribute declarations function and complicates rules for eliminating duplicate SCDs.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0222.html.

See also http://www.w3.org/TR/2003/WD-xmlschema-ref-20030109/#issue_mg_dups.

See also http://www.w3.org/TR/2003/WD-xmlschema-ref-20030109/#issue_ag_dups.

RQ-133 scd-accessible-constraints: Identity constraints accessibility in component graph

Locus: structures Cluster: SCD
Class: Req Status: overtaken
Assigned to:
Originator: Asir Vedamuthu, Mary Holstege

Description

While identity constraints are available through the element to which they are bound, as named members in their own symbol space, it would be beneficial to have them directly available at the top level, i.e. from a property on the schema-as-a-whole schema component.

add a property to schema-as-a-whole component; text analogous to those for complex type definitions, in section 2 (symbol spaces), schema-as-a-whole component description, and in QName resolution.

Decided on June 26th to call it erratum and we're waiting for text.

See RQ-16. These two issues are related.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0222.html.

Interactions and Input

This item was mentioned in the meeting of 2003-09-18

This item was closed in the meeting of 2004-04-02. It does not need to be done for 1.1, because it should be taken care of as an erratum to XML Schema 1.0 (see R-105). Cf. also RQ-16.

RQ-134 scd-origin-inheritance: Origin of inherited portions of content model

Locus: structures Cluster: SCD
Class: Req Status: roughed
Assigned to:
Originator: Asir Vedamuthu, Mary Holstege

Description

Today, there is no mechanism to trace back the origin of some of the components that were assembled via compiling a complex/simple type definition. Suppose one type extends another type by adding additional terms to a sequence. In the schema component model there is no direct way to determine which terms in the sequence come from the base type: the inheritance is "compiled out" as it were.

How does this issue apply to Simple Type Definition? via Simple Type Definition.{facets} property. This property is a union of the set of Facets components resolved to by the facet [children] merged with {facets} from {base type definition}, subject ..

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Oct/0222.html.

See also http://www.w3.org/TR/2003/WD-xmlschema-ref-20030109/#issue_derived_cm_not_manifest.

Interactions and Input

This item was classified as Req in the meeting of 2004-03-11.

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-04-02.

RQ-135 component-consistency-and-validity: Consistency and validity for a set of schema components

Locus: structures Cluster: XSD
Class: Opp.Des. Status: todo
Assigned to:
Originator: Matthew Fuchs

Description

On 10 June 2004 the WG adopted the following wording for this requirement:

Eliminate errors at a distance. A legal schema remains legal if you add components to it, unless the components you add are themselves faulty or try to redefine components already present.

The original wording follows.

We call a set of schema components "valid" if it is transitively closed over references and contains no errors.

We call two sets of schema components "consistent" if, for any namespace where they contain components from the same namespace, those components can be written using exactly the same transfer syntax.

The proposed requirement is, that given two sets of schema components that are both transitively closed over references and valid, if they are consistent, then their union is transitively closed over references and valid.

Matthew says: "I believe we currently have this property, or it's violations are so far at the limit, that no schemas would be affected by the change. On the other hand, this is a crucial property for customers, and they will be _very_, _very_ unhappy if we violate it. Maybe not right away, but they will when it starts to affect them."

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0106.html .

Interactions and Input

This item was discussed in the meeting of 2003-10-24

This item was discussed in the meeting of 2003-12-05

This item was discussed in the meeting of 2004-01-08

This item was discussed in the meeting of 2004-01-15

This item was discussed in the meeting of 2004-01-22

The WG formed task forces to prepare further work on this item in the meeting of 2004-02-27

This item was discussed in the meeting of 2004-03-18.

This item was discussed in the meeting of 2004-05-28.

This item was classified as Opp.Des. in the meeting of 2004-06-10.

RQ-137 error-codes: Provide error codes for all violations

Locus: both Cluster: XSD
Class: Req Status: roughed
Assigned to:
Originator: Sandy Gao

Description

There are a number of areas where the recommendations state certain rules, but there are no corresponding constraints for them, hence there are no proper error codes.

In addition, there should be an explicit constraint that all schemas must conform to the schema for schemas, thus providing an error code to refer to.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Jun/0088.html.

See also http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2002Nov/0237.html.

Interactions and Input

This item was classified in the meeting of 2003-10-24

This item was discussed in the meeting of 2003-11-04

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-18.

RQ-138 nillable-and-fixed: Nillable and Fixed are allowed together

Locus: structures Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: Sandy Gao, Asir Vedamuthu

Description

Consider:

<xs:element name="e" nillable="true" type="xs:string" fixed="abc"/>

The spec says it's allowed. But "nillable" can never be actually used. If it is used, then the following constraint makes the instance invalid:

"Validation Rule: Element Locally Valid (Element)

  • 3.2 If {nillable} is true and there is such an attribute information item and its actual value is true , then all of the following must be true:

  • 3.2.1 The element information item must have no character or element information item [children].

  • 3.2.2 There must be no fixed {value constraint}.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2003Jul/0005.html.

See also http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2001May/0020.html.

Interactions and Input

This item was classified as a non-goal in the meeting of 2003-10-24

RQ-139 URI-subtype-of-string: Make anyURI a subtype of string

Locus: datatypes Cluster: D/T
Class: Non-goal Status: ng
Assigned to:
Originator: Jim Melton

Description

QT has asked to reclassify anyURI as subtype of string; all use cases are recasting to string anyway.

See member-only minutes http://www.w3.org/XML/Group/2003/07/xml-schema-ftf-minutes..

See also member-only mail http://lists.w3.org/Archives/Member/w3c-xml-query-wg/2003Jul/0115.html.

Interactions and Input

This item was classified as a desideratum in the meeting of 2003-08-28

This item was discussed in the meeting of 2003-09-18. The consensus there was that we should not make anyURI a subtype of string, and that we should push back to QT against the behavior of Functions and Operators.

This item was discussed and then reclassified as a non-goal in the meeting of November 2003 in Redwood Shores.

Actual Resolution

At the meeting in Redwood Shores the XML Schema WG declined to make this change on the grounds that the semantics of anyURI are different from those of string.

RQ-140 negative-positive-zero: Distinguish negative from positive zero.

Locus: datatypes Cluster: Num
Class: Req Status: drafted
Assigned to:
Originator: XML Schema WG

Description

R-22 says "The dataypes spec has some inconsistencies with IEEE with respect certain special values ...". It continues "Are +0 and -0 the same value?" Further, the F&O discusses both positive and negative zero as arguments to functions that accept float and double values. In some cases this is required by backwards compatibility with XPath 1.0 functions such as "round".

Interactions and Input

This item was mentioned in the meeting of 2003-09-18.

This item was discussed (and phase-1 agreement was reached) in the meeting of 2003-09-18.

This item was discussed in the meeting of 2003-10-16.

This item was discussed in the meeting of 2003-10-17.

This item was discussed in the meeting of 2003-11-21.

This item was discussed (editors noted that they had long ago proposed wording) in the meeting of 2004-04-29.

RQ-141 anyAtomicType: Add the abstract datatype anyAtomicType

Locus: datatypes Cluster: Dat
Class: Req Status: roughed
Assigned to:
Originator: XML Schema WG

Description

Should we add anyAtomicType as requested by QT? Should we add it as the supertype of all atomic types or as a union of all atomic types?

Interactions and Input

This item was discussed in the meeting of 2003-09-18

This item was discussed in the meeting of 2003-09-26

This item was discussed in the meeting of 2003-10-02

This item was discussed, and phase-1 agreement was reached, in the meeting of 2004-03-19.

RQ-142 PSVIProp: Are non-required PSVI properties forbidden?

Locus: structures Cluster: PSVI
Class: Req Status: roughed
Assigned to:
Originator: Lisa Martin

Description

There are various statements in the spec of the form: "If some condition, x, is true, then, in the post-schema-validation infoset it has the properties a,b,c ..."

For example:

"If an element is valid with respect to a type definition, as per Element Locally Valid (Type), in the post-schema-validation infoset the item has a property ...

Furthermore, the item has one of the following alternative sets of properties:

[type definition]

...

" Is it true that if condition x does *not hold*, then the processor is *not permitted* to include properties a,b,c in the PSVI, even if such information is available? I'm assuming this is what was intended, based on the clarifications drafted for the Query WG on the topic of PSVI.

If this is the case, should the Structures spec clarify this? ...perhaps with wording similiar to: "The properties a, b, c are in the PSVI if and only if ..."

As an aside, wouldn't it be useful to get at type information for an element that was not valid, if the processor had that information?

Interactions and Input

This item was discussed in the meeting of 2004-03-25. Three points were identified as close to consensus:

1 We should eliminate any dependency on the absence of specific properties (i.e. important situations should be describable and distinguishable in terms of properties and their values, without appeal to the absence of particular properties), or if this proves unfeasible in particular cases we should say explicitly that a property is present "if and only if" certain conditions apply. Any remaining "if" (if any) would be a true conditional, not an equivalence.

2 Any specification of a class of processors (including ours) can require specific additional information not in the PSVI, though should note that interoperability is better if applications depend only on the properties present in the PSVI as we define it.

3 In our own specification of processor classes, we should be explicit that processors may provide additional information. (Or alternatively be explicit that they must not -- but the chair believes the WG consensus was to allow it.)

This item was discussed in the meeting of 2004-04-01. Phase 1 agreement was reached on point 1 above. The other two points were moved to RQ-144.

RQ-143 AssessmentOfAtts: Question about assessment outcome for attributes

Locus: structures Cluster: Str
Class: Req Status: todo
Assigned to:
Originator: Richard Tobin

Description

Assessment Outcome (Attribute) only applies to attributes that have been assessed. Since there is no difference between assessment and strict assessment for an attribute, an attribute that has not been strictly assessed will never have a [validation attempted] property, so it is impossible for the [validation attempted] property to be none. Similarly the [validity] property can never be notKnown.

This seems odd. An attribute with no type declaration cannot be assessed (Schema-Validity Assessment (Attribute)), so it will never have any PSVI properties, whereas it would be natural for it to have [validation attempted] = none and [validity] = notKnown.

See the following mail: http://lists.w3.org/Archives/Public/www-xml-schema-comments/2002JulSep/0003.html

Actual Resolution

Discussed at the Sept. 20, 2003 concall.

RESOLVED: to classify R-167 as clarification without erratum, and to bring the issue up again in the context of 1.1.

RQ-144 WhichPSVIPropertiesReqd: Which PSVI properties must processors report?

Locus: PSVI Cluster: Str
Class: Req Status: active
Assigned to:
Originator: Noah Mendelsohn

Description

[N.B. this candidate requirement was originally posed in the terms given by the email from Noah Mendelsohn cited below; it was amended on 25 March 2004 to read as follows:]

"[Definition:] Minimally conforming processors must completely and correctly implement the Schema Component Constraints, Validation Rules, and Schema Information Set Contributions contained in this specification."

Which at least appears to require that conforming processors report the PSVI. This would rule out, for example, processors that implement a simple validation check function such as:

     boolean IsValid(schema, instance) 

a function which is clearly useful in query languages, spreadsheets, and other systems that manage or access instance documents. Other interesting if somewhat less common reports might be to give only the type assignments of each element or attribute, etc. Even for validity, some applications will want details of validity down the entire tree, while others will want only the net result at the root. Interestingly, many applications will want the "value" from a simple type value space, which for some reason we have declined to include.

The range of useful processor APIs goes well beyond providing the full PSVI and only that. We should modify the spec in the light of that fact.

See mail: from Noah Mendelsohn

Interactions and Input

This item was discussed in the meeting of 2004-03-11.

This item was discussed and amended in the meeting of 2004-03-25. The amended requirement was classified as Req.

This item was discussed in the meeting of 2004-04-01. We identified two points (originally formulated as part of RQ-142 but moved here by WG decision):

Any specification of a class of processors (including ours) can require specific additional information not in the PSVI, though should note that interoperability is better if applications depend only on the properties present in the PSVI as we define it.

In our own specification of processor classes, we should be explicit that processors may provide additional information. (Or alternatively be explicit that they must not -- but the chair believes the WG consensus was to allow it.)

RQ-145 Value-Property: Add a "value" property for attributes and elements with simple content.

Locus: PSVI Cluster: Str
Class: Non-goal Status: ng
Assigned to:
Originator: Noah Mendelsohn

Description

Add a [value] property to the PSVI for attributes and for elements validated with simple content. This candidate requirement is facilitated by RQ-144, as we make clear that the [value] property need be computed only if needed.

With a [value] property, we can also suggest to Query that they augment the famously vague Data Model stipulation that:

"In the general case, dm:typed-value constructs a sequence of atomic values. These values are derived from the string-value of the element and its type, in such a way as to be consistent with validation."

Instead, or in addition one could put into their PSVI-to-DM mapping:

"string-value (unchanged)

The [schema normalized value] PSVI property if that exists, or the [normalized value] property.

typed-value (new)

The [value] PSVI property (reference to new PSVI property)

See mail: from Noah Mendelsohn

Interactions and Input

In its meeting of 2004-03-12, the Working Group decided (Henry Thompson dissenting) to classify this item as Non-goal.

This item was discussed in the meeting of 2004-05-13.

RQ-146 ElementDeclarationsConsistent: needs clarification re. wildcards

Locus: PSVI Cluster: Str
Class: Req Status: active
Assigned to:
Originator: David Bau

Description

Consider the following "tricky" indirect case involving a wildcard referencing a global element:

<element name="a" type="string"/>
<complexType name="example-2">
  <sequence>
    <element name="a" type="int"/>
    <element name="whatever"/>
    <any namespace="##targetNamespace" processContents="lax"/>
  </sequence>
</complexType>

Clearly the local <a> and the indirect reference to the global <a> are "inconsistent" with each other within the content model of the above example but I'm not sure if the "directly, indirectly, or implicitly" language in the EDC rule captures this case.

See mail from: David Bau. See reply from: from Henry Thompson.

Interactions and Input

Proposals to discharge this requirement also cover RQ-17.

This item was classified as Req in the meeting of 2004-03-12.

This item was discussed in the meeting of 2004-04-09, in connection with RQ-17..

RQ-147 E2-35-length-facets: Allow "length" after "min/maxLength", but not the other way around.

Locus: PSVI Cluster: Str
Class: nongoal Status: ng
Assigned to:
Originator: Noah Mendelsohn

Description

E2-35 makes the following declarations valid:

<simpleType name="st1">
  <restriction base="string">
    <length value="5"/>
  </restriction>
</simpleType>

<simpleType name="st2">
  <restriction base="st1">
    <minlength value="2"/>
  </restriction>
</simpleType> 

But the second derivation step doesn't seem to mean anything. This is analogous to having minInclusive=10 in the base and minExclusive=0 in the derived, which is not allowed by the spec.

It seems to be a good change to allow "length" after "min/maxLength", but not the other way around.

See mail from: Sandy Gao.

Ashok Malhotra replied that, perhaps for Schema 1.1, we should remove the length facet and make setting the length facet syntactic sugar for setting both maxLength and minLength to the same value. See: Ashok Malhotra.

Interactions and Input

This item was classified as nongoal in the meeting of 2004-04-08.

RQ-147b E2-35-length-facet: Make "length" specifications set "min/maxLength" facets, not a separate facet.

Locus: PSVI Cluster: Str
Class: Desideratum Status: todo
Assigned to:
Originator: Noah Mendelsohn

Description

Phase out the length facet in favor of making length specifications in the schema document set the minLength and maxLength facets.

See also discussion of RQ-147 (non-goal).

See mail from: Sandy Gao.

Interactions and Input

This item was classified as desideratum in the meeting of 2004-04-08.

RQ-148 Truncation-not-defined: Clarify the use of the word "truncation" in lexical forms.

Locus: datatypes Cluster: Dat
Class: Req Status: roughed
Assigned to:
Originator: Steven Taschuk

Description

Part 2: Datatypes frequently defines the lexical representation of one type as a "truncation" of that of another, without ever defining what is meant by this term. Sometimes it seems to have the conventional meaning of omitting characters from one end of a string, as in:

The lexical representation for gYear is the reduced (right truncated) lexical representation for dateTime: CCYY. [section 3.2.11.1] Other times the omitted characters are replaced by other characters, as in:

The lexical representation for gDay is the left truncated lexical representation for date: ---DD . [section 3.2.13.1] It's not difficult to understand what is meant, but the document overall aspires to (and for the most part handily achieves) a higher standard of precision. For consistency, I'd like to see the term defined in 1.1.

See mail from: Steven Taschuk.

This is R-190. On the 11/21/2008 telcon we agreed to add to the 1.1 Requirements and classify as "Clarification without Erratum"

Interactions and Input

This item was discussed in the meeting of 2004-05-12.

RQ-149 Drop-numeric-exponents-on-moddel-groups: Deprecate use of numeric exponents on model groups

Locus: structures Cluster: Str
Class: Non-goal Status: abandoned
Assigned to:
Originator: Xan Gregg

Description

Xan Gregg: Also known as "numeric exponents", when applied to model groups these cause inordinate complexity for subsumption testing on state machines generated from content models. Numeric exponents refer to occurrence constraints besides 0, 1, and unbounded (the values supported natively by regular expressions).

When asked, the WG members have been unable to point to a good use of such occurrence values. Henry Thomspon has noted in [1] that of the 700 schemas contributed by XSV users, there was only one non-trivial use of numeric exponents on a model group:

  <seq min=1 max=3>
   <elt min=0/>
   <elt min=0/>
   <elt min=0/>
  </seq>

For completeness, I have also noted one contrived case [2] that was found in a tutorial:

sandwich ::=
    lower_slice 
    [ mustard | mayonnaise ]
    lettuce? tomato?
    [ bologna | salami | ham ] {2,4}
    cheese+
    top_slice

The WG discussion broadened the scope of this issue to numeric exponents in general, not only for model groups.

[1]Henry Thompson

[2]J. David`Eisenberg

Interactions and Input

This item was discussed in the meeting of 2004-04-15.

This item was abandoned in the meeting of 2004-05-13.

RQ-150 Minimum-number-of-digits-for-decimal: Problems with minimum number of digits for decimal

Locus: datatypes Cluster: Dat
Class: Req Status: roughed
Assigned to:
Originator: John Tebbutt, Ashok Malhotra

Description

John Tebbutt: Ashok Malhotra:

Interactions and Input

This item was discussed in the meeting of 2003-12-19

This item was discussed in the meeting of 2003-12-18

This item was discussed in the meeting of 2003-10-31

This item was discussed in the meeting of 2003-10-30

This item was discussed in the meeting of 2003-11-04

This item was classified as requirement and discussed, and phase-1 agreement was reached, in the meeting of 2004-04-08.

RQ-151 composition: Define schema composition

Locus: structures Cluster: XSD
Class: Req Status: active
Assigned to:
Originator: Xan Gregg

Description

Give a complete and formal definition of schema composition, and use it for currently defined (e.g. include) and currently undefined (e.g. schema docs on command line) cases.

See http://lists.w3.org/Archives/Member/w3c-xml-schema-ig/2004Jun/0058.html.

Interactions and Input

This item was classified as Req in the meeting of 2004-06-10.

RQ-152 xml1.1: Should XML Schema be aligned with XML 1.1?

Locus: both Cluster: unassigned
Class: Unclassified Status: proposed
Assigned to:
Originator: Henry Thompson, Noah Mendelsohn

Description

Should XML Schema 1.1 be aligned with XML 1.1? Some salient points on which XML 1.1 differs from XML 1.0 include:

Several points on which alignment may be needed have been identified; in the words of Henry Thompson (first item) and Noah Mendelsohn (others):

  1. XML 1.1 adds #x85 and #x2028 to the characters involved in line break normalization. XML Schema may need to change our whitespace handling in 1.1 to take account of this.
  2. We use Infosets for instances and schemas. There is a question as to how one knows whether the new names and content might appear in such an Infoset. It may be implied that the switch is to be found in the [version] property of the document information item. Concerns regarding the Infoset include:
    • While the version property is indeed in the Infoset rec, and the 2nd addition talks about needing a processor that can handle whatever serialized document you might have, I don't think it specifically ties the legal values of properties such as the [local name] of an element or legal [character codes] to this [version] property. Synthetic Infosets, for example, need to be covered IMO. For example, the newly published Infoset Rec says "[character code] The ISO 10646 character code (in the range 0 to #x10FFFF, though not every value in this range is a legal XML character code) of the character.", which seems a bit vague on what it means to be an XML character.
    • We in schemas define both schema "documents" and instances to be validated as element information items, with no reference to a required or containing document information item. I think we need to consider whether the [version] property of the doc info item would meet our need to determine what version of XML we've got with respect to instances and (purported) schema documents.
  3. Our xsd:string type explicitly refers to the char production of XML 1.0 2nd addition. Thus, it will not validate strings containing the control characters of XML 1.1. We could perhaps introduce a new type that would validate the new content, but there are complications, including:
    • xsd:string is base for types like xsd:token, so we might have to create parallel versions of some of those
    • If you wanted to write a schema document that had an enumeration or fixed value constraint containing the new characters, then that schema document would have to be expressed as an XML 1.1 Infoset (see comment above regarding possible ambiguity about which Infosets are 1.1)
    • Our pattern language is designed to constrain strings, but as I read the spec it defines "A normal character is any XML character that is not a metacharacter." With the publication of XML 1.1 we see in hindsight that this is insufficiently precise.
  4. Since the range of legal element names has changed, we face questions regarding our ability to validate element and attribute content using the new names.
    • If your schema is written as a schema document, then presumably you can only enter the names if the document is an XML 1.1 Infoset (similar to concern raised for enumerations on strings)
    • Since the range is implicitly extensible as Unicode changes, it would seem that even a label of XML 1.1 on an infoset for a schema document does not ensure that it has the expressive power to name all the XML element and attribute names that one might wish to validate. Some processor might be checking the schema document with knowledge of, say Unicode 4.0, but the schema document might have been written with knowledge of a Unicode 5.0 that "assigned" no characters.
    • We have types such as xsd:name about which our Recommendation says "[Definition:] Name represents XML Names. The value space of Name is the set of all strings which match the Name production of [XML 1.0 (Second Edition)]. The lexical space of Name is the set of all strings which match the Name production of [XML 1.0 (Second Edition)]. The base type of Name is token. " Note that xsd:token is derived from xsd:string, which is discussed above.
    • We have an xsd:Qname type, the definition of which is "[Definition:] QName represents XML qualified names. The value space of QName is the set of tuples {namespace name, local part}, where namespace name is an anyURI and local part is an NCName. The lexical space of QName is the set of strings that match the QName production of [Namespaces in XML]." That link to [Namespaces in XML] is explicitly to: "World Wide Web Consortium. Namespaces in XML. Available at: http://www.w3.org/TR/1999/REC-xml-names-19990114/", which is to the 1999 Namespaces in XML recommendation.
    • We use that QName type in the schema for schemas for the names of elements and attributes to be validated, as well as for references within schemas.
    • Our component descriptions tend to have {name} properties that constrain their content by that same 1999 version of Namespaces. See for example the element declaration schema component. In general, there is a necessary tie between what we can put in these component properties, what we can express in a serialized schema document, what we can express in the corresponding schema document infoset, what's allowed by the xsd:Qname type, and the names of elements and attributes we can validate.
  5. Our type system is used by others such as query, both in the data model and as the type system for functions and operators. As we wrestle with the definitions of types like xsd:string and xsd:name, I presume that some intensive liaison with them will be needed. It's not implausible that if we introduce an xsd:stringv11 type, that duplicate functions would be needed for every F&O function that accepts or returns a string. Likewise for xsd:Qname, etc. Other groups such as XMLP and RDF also use our type system and might be affected by changes or by lack of synergy with XML 1.0 or XML 1.1.
  6. We talk about the representation of XML schema documents for retrieval on the web. The pertinent part of the description of the web resource to be retrieved says: "It resolves to (a fragment of) a resource which is an XML document (of type application/xml or text/xml with an XML declaration for preference, but this is not required), which in turn corresponds to a <schema> element information item in a well-formed information set, which in turn corresponds to a valid schema." It seems we now need to be clearer as to if and when such documents may have <?xml version="1.1"?>, what the rules are for cross-importing and including across versions, etc. All of these must be related to whatever we decide above regarding rules for our components, types, enumeration constraints, etc.

Interactions and Input

See note to comments list on 6 February 2004 from Henry Thompson.

See note to comments list on 19 February 2004 from Noah Mendelsohn.

See also proposed erratum for XML Schema 1.0 sent on 8 June 2004 by C. M. Sperberg-McQueen (and ensuing discussion).

RQ-153 xsd-1.1-namespace: Schema 1.1 Namespace

Locus: both Cluster: unassigned
Class: Unclassified Status: proposed
Assigned to:
Originator: David Ezell

Description

The XML Schema 1.1 specification must choose either to use the same namespace as 1.0, or to use a different namespace, or to use more than one namespace. An explicit decision should be made.

In our general outline of compatibility goals for 1.1, the WG agreed that we would avoid changes to the XML transfer syntax, in order that XML Schema 1.0 processors can successfully process 1.1 schema documents. This seems to some to entail making no change in the namespace.

At the same time, we also agreed that changes to the XML transfer syntax might be made nevertheless, if they were necessary in order to support versioning better. This seems to some to imply that any final decision on whether we will make breaking changes is still out; if we do, some WG members will wish to entertain the possibility of changing the namespace, or adding additional namespaces.

Interactions and Input

This topic was raised in the Working Group call of 1 July 2004, and it was agreed to create a separate requirement to make it easier to track.