4.12.2 Typeswitch

Introduction

"This variable is optional in [XPath/XQuery] but mandatory in the
[XPath/XQuery] Core."
    Not according to the Core Grammar.

"One of the reasons for having this variable is that it is assigned a
specific type for the corresponding branch."
    Is this a reason for requiring the variables in the Core, or a reason
    for someone to use them in XQuery? If the former, I don't find it
    convincing. If the latter, reword and move it before the preceding
    sentence, so it isn't mistaken for the former.

Core Grammar
    I guess you should make the $VarNames mandatory, if that's what you
    want.

Norm
"The following normalization rule adds a newly created variable that does
not appear in the rest of the query. Note that $fs:new is a newly
generated variable that must not conflict with any variables already in
scope and that is not used in any of the sub-expressions."
    These two sentences say roughly the same thing. Merge.
    Also, s/rule/rules/, as it applies to rules 1 and 3.

Notation 2

"The following auxiliary grammar production is used to identify branches
of the typeswitch."
    I don't think "identify" is the correct verb. CaseRules is a
    right-recursive restructuring of the clauses of a TypeswitchExpr.

"[79 (Formal)] CaseRules ::= ..."
    Why not use this in the actual Core grammar?
    (leftover from last year, comment #111)

    I don't think 'CaseRules' is a very good name, especially in a
    document where "rule" already means something quite different.
    How about 'CaseClauses'?

"statEnv |- Type1 case CaseRules : Type"
    No, this judgment is not applied to CaseRules, but only to individual
    clauses. So, you could declare it twice, once for CaseClause and once
    for a default clause. (It would help if Core had a DefaultCaseClause.)

is used in the static of"
    Insert "semantics" after "static"?

"the given case rule yields the type Type"
    s/rule/clause/

"the given case rules yields the value Value2."
    s/rules/clauses/
    s/yields/yield/

DEv

"the remaining case rules are evaluated order"
    s/rules/clauses/
    Insert "in" before "order".

DEv / rule 3 / conclusion
case SequenceType VarRef # -> # case VarRef as SequenceType
leftover comment #112

DErr
"evaluation of any case rule"
    s/rule/clause/