From 5c2e09dfe4fe6ada531c6454c2455ac00f4ccb5d Mon Sep 17 00:00:00 2001
From: "A.J. Stein" <alexander.stein@nist.gov>
Date: Thu, 22 Feb 2024 08:39:06 -0500
Subject: [PATCH] Allow only let in constraint for XML schema for #548

---
 schema/xml/metaschema.xsd | 23 ++++++++++-------------
 1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/schema/xml/metaschema.xsd b/schema/xml/metaschema.xsd
index ab56aec2..c469bfab 100644
--- a/schema/xml/metaschema.xsd
+++ b/schema/xml/metaschema.xsd
@@ -1175,20 +1175,14 @@
     <xs:attribute name="expression" type="MetaschemaPathType" use="required"/>
   </xs:complexType>
 
-  <xs:group name="LetExpressionGroup">
-    <xs:sequence>
-      <xs:element name="let" type="ConstraintLetType" minOccurs="0" maxOccurs="unbounded">
-        <xs:annotation>
-          <xs:documentation>Declares a variable whose name is bound to the result of the Metapath expression. These variables can be used in target and other Metapath expressions used in constrains that are declared in the same context or in constraints declared in a child assembly, field, or flag.</xs:documentation>
-        </xs:annotation>
-      </xs:element>
-    </xs:sequence>
-  </xs:group>
-
   <xs:complexType name="DefineFlagConstraintsType">
     <xs:sequence>
-      <xs:group ref="LetExpressionGroup"/>
       <xs:choice maxOccurs="unbounded">
+        <xs:element name="let" type="ConstraintLetType">
+          <xs:annotation>
+            <xs:documentation>Declares a variable whose name is bound to the result of the Metapath expression. These variables can be used in target and other Metapath expressions used in constrains that are declared in the same context or in constraints declared in a child assembly, field, or flag.</xs:documentation>
+          </xs:annotation>
+        </xs:element>
         <xs:element minOccurs="0" name="allowed-values" type="AllowedValuesType">
           <xs:annotation>
             <xs:documentation>Constrains the allowed values for the flag.</xs:documentation>
@@ -1216,6 +1210,11 @@
   
   <xs:group name="TargetedCommonConstraintsGroup">
     <xs:choice>
+      <xs:element name="let" type="ConstraintLetType">
+        <xs:annotation>
+          <xs:documentation>Declares a variable whose name is bound to the result of the Metapath expression. These variables can be used in target and other Metapath expressions used in constrains that are declared in the same context or in constraints declared in a child assembly, field, or flag.</xs:documentation>
+        </xs:annotation>
+      </xs:element>      
       <xs:element name="allowed-values" type="TargetedAllowedValuesConstraintType">
         <xs:annotation>
           <xs:documentation>Constrains the allowed values for the flag or field referenced by the scope attribute.</xs:documentation>
@@ -1261,7 +1260,6 @@
 
   <xs:complexType name="DefineFieldConstraintsType">
     <xs:sequence>
-      <xs:group ref="LetExpressionGroup"/>
       <xs:choice minOccurs="1" maxOccurs="unbounded">
         <xs:group ref="TargetedCommonConstraintsGroup"/>
       </xs:choice>
@@ -1271,7 +1269,6 @@
 
   <xs:complexType name="DefineAssemblyConstraintsType">
     <xs:sequence>
-      <xs:group ref="LetExpressionGroup"/>
       <xs:choice minOccurs="1" maxOccurs="unbounded">
         <xs:group ref="TargetedCommonConstraintsGroup"/>
         <xs:group ref="AssemblyConstraintsGroup"/>