Fix "for member" grammar problems

michaelhkay · Oct 16, 2023 · 480c62f · 480c62f
1 parent 0e26cd8
commit 480c62f
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Showing 2 changed files with 41 additions and 11 deletions.
diff --git a/specifications/grammar-40/xpath-grammar.xml b/specifications/grammar-40/xpath-grammar.xml
@@ -943,7 +943,6 @@ VersionDecl ::= "xquery" (("encoding" StringLiteral) | ("version" StringLiteral
   <g:production name="InitialClause" if="xquery40">
     <g:choice>
       <g:ref name="ForClause" lookahead="2"/>
-      <g:ref name="ForMemberClause" lookahead="2"/>
       <g:ref name="LetClause"/>
       <g:ref name="WindowClause" lookahead="2"/>
     </g:choice>
@@ -967,8 +966,15 @@ VersionDecl ::= "xquery" (("encoding" StringLiteral) | ("version" StringLiteral
       <g:ref name="ForBinding"/>
     </g:zeroOrMore>
   </g:production>
-
+  
   <g:production name="ForBinding" if="xquery40">
+    <g:choice>
+      <g:ref name="ForItemBinding"/>
+      <g:ref name="ForMemberBinding"/>     
+    </g:choice>
+  </g:production>
+
+  <g:production name="ForItemBinding" if="xquery40">
     <g:string>$</g:string>
     <g:ref name="VarName"/>
     <g:optional>
@@ -987,14 +993,28 @@ VersionDecl ::= "xquery" (("encoding" StringLiteral) | ("version" StringLiteral
     <g:ref name="ExprSingle"/>
   </g:production>
 
+  <g:production name="ForMemberBinding" if="xquery40">
+    <g:string>member</g:string>
+    <g:string>$</g:string>
+    <g:ref name="VarName"/>
+    <g:optional>
+      <g:ref name="TypeDeclaration"/>
+    </g:optional>
+    <g:optional>
+      <g:ref name="PositionalVar"/>
+    </g:optional>
+    <g:string>in</g:string>
+    <g:ref name="ExprSingle"/>
+  </g:production>
+
 
 
   <g:production name="AllowingEmpty" if="xquery40">
     <g:string>allowing</g:string>
     <g:string>empty</g:string>
   </g:production>
 
-  <g:production name="ForMemberClause" if="xquery40">
+  <!--<g:production name="ForMemberClause" if="xquery40">
     <g:string>for</g:string>
     <g:string>member</g:string>
     <g:ref name="ForMemberBinding"/>
@@ -1015,7 +1035,7 @@ VersionDecl ::= "xquery" (("encoding" StringLiteral) | ("version" StringLiteral
     </g:optional>
     <g:string>in</g:string>
     <g:ref name="ExprSingle"/>
-  </g:production>
+  </g:production>-->
 
   <g:production name="PositionalVar" if=" xquery40">
     <g:string>at</g:string>

diff --git a/specifications/xquery-40/src/expressions.xml b/specifications/xquery-40/src/expressions.xml
@@ -16164,6 +16164,8 @@ return .($k)
             <prodrecap id="IntermediateClause" ref="IntermediateClause"/>
             <prodrecap ref="ForClause"/>
             <prodrecap ref="ForBinding"/>
+            <prodrecap ref="ForItemBinding"/>
+            <prodrecap ref="ForMemberBinding"/>
             <prodrecap ref="LetClause"/>
             <prodrecap ref="LetBinding"/>
             <prodrecap id="TypeDeclaration" ref="TypeDeclaration"/>
@@ -16287,8 +16289,8 @@ let $z := g($x, $y)]]></eg>
             <scrap>
                <head/>
                <prodrecap id="ForClause" ref="ForClause"/>
-               <prodrecap id="ForMemberClause" ref="ForMemberClause"/>
                <prodrecap id="ForBinding" ref="ForBinding"/>
+               <prodrecap id="ForItemBinding" ref="ForItemBinding"/>
                <prodrecap id="ForMemberBinding" ref="ForMemberBinding"/>
                <prodrecap ref="TypeDeclaration"/>
                <prodrecap ref="AllowingEmpty"/>
@@ -16342,7 +16344,8 @@ for member $y in $expr2]]></eg>
                   def="dt-implementation-dependent">implementation-dependent</termref>.</p>
             <p>If the <termref def="dt-binding-sequence"
                   >binding collection</termref> is empty, the output tuple stream depends on whether <code>allowing empty</code> is specified. 
-               If <code>allowing empty</code> is specified, the output tuple stream consists of one tuple in which the variable is bound to an empty sequence. 
+               If <code>allowing empty</code> is specified, the output tuple stream consists of one tuple in which the variable is bound to an empty sequence.
+               This option is not available with "for member".
                If <code>allowing empty</code> is not specified, the output tuple stream consists of zero tuples.</p>
             <p>The following  examples illustrates tuple streams that are generated by initial <code>for</code> clauses:</p>
             <ulist>
@@ -16453,11 +16456,18 @@ for member $y in $expr2]]></eg>
             </note>
             <p>For a given input tuple, if the <termref def="dt-binding-collection" diff="chg" at="A"
                   >binding collection</termref> for the new variable in the <code>for</code> clause <phrase diff="add" at="A">is empty 
-               (that is, it is an empty sequence or an empty array depending on whether <code>member</code> is specified)</phrase>, 
-               the result depends on whether  <code>allowing empty</code> is specified. If <code>allowing empty</code> 
-               is specified, the input tuple generates one output tuple, with the original variable bindings plus a 
-               binding of the new variable to an empty sequence. If <code>allowing empty</code> is not specified, 
-               the input tuple generates zero output tuples (it is not represented in the output tuple stream.)</p>
+               (that is, it is an empty sequence or an empty array depending on whether <code>member</code> is specified)</phrase>,
+               and if <code>allowing empty</code> is not specified, the input tuple generates zero output tuples 
+               (it is not represented in the output tuple stream.)</p>
+
+            <p diff="chg" at="2023-10-16">The <code>allowing empty</code> option is available only when processing sequences, not when processing arrays.
+               The effect is that if the binding collection is an empty sequence, the input tuple generates one output tuple, 
+               with the original variable bindings plus a binding of the new variable to an empty sequence.</p>
+
+            <note diff="add" at="2023-10-16"><p>If a type declaration is present and <code>allowing empty</code> is specified, the type declaration
+            should include an occurrence indicator of <code>"?"</code> to indicate that the variable may be bound to an
+            empty sequence.</p></note>
+
             <p>If the new variable introduced by a <code>for</code> clause has an associated <termref
                   def="dt-positional-variable"
                   >positional variable</termref>, the output tuples generated by the <code>for</code> clause  also contain bindings for the <termref