ISSUE-102: Missing a way to explicitly code unbound cardinality and open shapes

Specifying defaults

Missing a way to explicitly code unbound cardinality and open shapes

State:

CLOSED

Product:

SHACL Spec

Raised by:

Karen Coyle

Opened on:

2015-10-14

Description:

There are at least two SHACL defaults that cannot be explicitly coded: maxCount and open shape. Being able to code these would not change the behavior of the program, but would have advantages for training and for the documentation function of SHACL.

maxCount: maxCount cannot be written in SHACL because the count must be an integer, and there is therefore no way to express "unbounded". However, minCount 0, also a default, can be coded. The difference between them is not user-friendly because it has to do with the internals of SHACL and not user needs.

Possible solutions:
1) include a maxCount value in SHACL that means "unbounded"
2) remove minCount 0 to be symmetrical with maxCount and make both min and max defaults explicit in the documentation
3) leave SHACL as is, but create a maxCount value in the high-level language that is interpreted as the maxCount default in SHACL

open shape: Both open shape and closed shape could be considered as defaults in SHACL -- different communities will lean in one direction or the other. Because there is no obvious choice for default, it may not be obvious to users which is the default. The only indication that open is the default is the fact that there is an optional SHACL property that closes the shape.

Possible solutions:
1) include a SHACL property for the open shape constraint that has the same function as the default

Related Actions Items:

No related actions

Related emails:

1. Re: Proposal to close ISSUE-102 leaving this to other syntaxes (from holger@topquadrant.com on 2015-10-19)
2. Re: Proposal to close ISSUE-102 leaving this to other syntaxes (from kcoyle@kcoyle.net on 2015-10-17)
3. Proposal to close ISSUE-102 leaving this to other syntaxes (from holger@topquadrant.com on 2015-10-16)
4. shapes-ISSUE-102 (Specifying defaults): Some defaults cannot be explicitly coded [SHACL Spec] (from sysbot+tracker@w3.org on 2015-10-14)

Related notes:

Display change log