Update openCypher grammar description

- Including links to these from the CIP - Also update examples for the parser tests
opencypher · Jul 2, 2021 · 26f22bb · 26f22bb
1 parent 03bca92
commit 26f22bb
Show file tree

Hide file tree

Showing 4 changed files with 51 additions and 31 deletions.
diff --git a/cip/1.accepted/CIP2016-12-14-Constraint-syntax.adoc b/cip/1.accepted/CIP2016-12-14-Constraint-syntax.adoc
@@ -72,6 +72,16 @@ References to existing grammar parts:
 * https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=Expression[<Expression>]
 * https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=PropertyExpression[<PropertyExpression>]
 
+References to new grammar parts:
+
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=Command[<ConstraintCommand>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=CreateConstraint[<CreateConstraint>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=DropConstraint[<DropConstraint>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=ConstraintPredicate[<ConstraintPredicate>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=Unique[<Unique>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=NodeKey[<NodeKey>]
+* https://raw.githack.com/openCypher/openCypher/master/tools/grammar-production-links/grammarLink.html?p=GroupedPropertyExpression[<GroupedPropertyExpression>]
+
 The `REQUIRE` clause works exactly like the `WHERE` clause in a standard Cypher query, with the addition of also supporting the special constraint operators `IS UNIQUE`, `IS NODE KEY`, and the new `<GroupedExpression>` expression.
 This allows for complex concrete constraint definitions (using custom predicates) within the specified syntax.
 

diff --git a/grammar/basic-grammar.xml b/grammar/basic-grammar.xml
@@ -149,7 +149,7 @@
     </alt>
   </production>
 
-  <production name="RelType" rr:inline="true">
+  <production name="RelType" rr:inline="true" oc:legacy="true">
     : &WS; <non-terminal ref="RelTypeName"/>
   </production>
 
@@ -714,6 +714,9 @@
       OF
       ADD
       DROP
+      NODE
+      KEY
+      UNIQUE
     </alt>
   </production>
 
@@ -728,8 +731,6 @@
       ANY
       NONE
       SINGLE
-      NODE
-      KEY
     </alt>
   </production>
 

diff --git a/grammar/commands.xml b/grammar/commands.xml
@@ -68,41 +68,41 @@
 
   <!-- / NEW CONSTRAINT SYNTAX \ -->
 
-  <production name="CreateConstraint">
-    CREATE &SP; CONSTRAINT &SP; <non-terminal ref="ConstraintName"/> &SP;
-    FOR &SP; <non-terminal ref="ConstraintPattern"/> &SP;
-    REQUIRE &SP; <non-terminal ref="ConstraintExpression"/>
-  </production>
-
   <production name="DropConstraint">
-    DROP &SP; CONSTRAINT &SP; <non-terminal ref="ConstraintName"/>
+    DROP &SP; CONSTRAINT &SP; <non-terminal ref="SymbolicName"/>
   </production>
 
-  <production name="ConstraintName">
-    <non-terminal ref="SymbolicName"/>
-  </production>
-
-  <production name="ConstraintPattern">
-    <alt>
-      <seq>( &var; &label; ) </seq>
-      <seq>( ) - [ &var; <non-terminal ref='RelType'/> ] - ( ) </seq>
-    </alt>
+  <production name="CreateConstraint">
+    CREATE &SP; CONSTRAINT &SP; <non-terminal ref="SymbolicName"/> &SP;
+    FOR &SP; <non-terminal ref="Pattern"/> &SP;
+    REQUIRE &SP; <non-terminal ref="ConstraintPredicate"/>
   </production>
 
-  <production name="ConstraintExpression">
+  <production name="ConstraintPredicate">
     <alt>
-      <non-terminal ref="Uniqueness"/>
-      <non-terminal ref="NodeKey"/>
       <non-terminal ref="Expression"/>
+      <non-terminal ref="Unique"/>
+      <non-terminal ref="NodeKey"/>
     </alt>
   </production>
 
-  <production name="Uniqueness">
-    UNIQUE &SP; <non-terminal ref="PropertyExpression"/>
+  <production name="Unique">
+    <non-terminal ref="GroupedPropertyExpression"/> &SP; IS &SP; UNIQUE
   </production>
 
   <production name="NodeKey">
-    NODE &SP; KEY &SP; <non-terminal ref="PropertyExpression"/> <repeat>&WS; , &WS; <non-terminal ref="PropertyExpression"/></repeat>
+    <non-terminal ref="GroupedPropertyExpression"/> &SP; IS &SP; NODE &SP; KEY
+  </production>
+
+  <production name="GroupedPropertyExpression">
+    <alt>
+      <non-terminal ref="PropertyExpression"/>
+      <seq>
+        ( &WS; <non-terminal ref="PropertyExpression"/>
+        <repeat>&WS; , &WS; <non-terminal ref="PropertyExpression"/></repeat>
+        &WS; )
+      </seq>
+    </alt>
   </production>
 
   <!-- / LEGACY COMMANDS \ -->

diff --git a/tools/grammar/src/test/resources/cypher.txt b/tools/grammar/src/test/resources/cypher.txt
@@ -314,21 +314,30 @@ RETURN count(label) AS numLabels§
 CALL db.labels() YIELD x WHERE label CONTAINS 'User' AND foo + bar = foo RETURN count(label) AS numLabels§
 CREATE CONSTRAINT foo
 FOR (p:Person)
-REQUIRE UNIQUE p.name§
+REQUIRE p.name IS UNIQUE§
+CREATE CONSTRAINT foo
+FOR (p:Person)
+REQUIRE (p.name) IS UNIQUE§
+CREATE CONSTRAINT foo
+FOR (p:Person)
+REQUIRE (p.name, p.email) IS UNIQUE§
 CREATE CONSTRAINT baz
 FOR (p:Person)
-REQUIRE exists(p.name)§
+REQUIRE p.name IS NOT NULL§
 CREATE CONSTRAINT cru
 FOR ()-[r:REL]-()
-REQUIRE exists(r.property)§
+REQUIRE r.property > 5§
 DROP CONSTRAINT foo_bar_baz§
 CREATE CONSTRAINT nodeKey
 FOR (n:Node)
-REQUIRE NODE KEY n.prop§
+REQUIRE n.prop IS NODE KEY§
+CREATE CONSTRAINT nodeKey
+FOR (n:Node)
+REQUIRE (n.prop) IS NODE KEY§
 CREATE CONSTRAINT nodeKey
 FOR (n:Node)
-REQUIRE NODE KEY n.p1, n.p2, n.p3§
+REQUIRE (n.p1, n.p2, n.p3) IS NODE KEY§
 CREATE CONSTRAINT nodeKey
 FOR (n:Node)
-REQUIRE NODE KEY n.p1   ,n.p2,    n.p3§
+REQUIRE (  n.p1   ,n.p2,   n.p3    ) IS    NODE   KEY§
 DROP CONSTRAINT foo§