From 1fd0cbf61be7da54649e853c4eb4162ec27498eb Mon Sep 17 00:00:00 2001
From: Mats Rydberg <mats@neotechnology.com>
Date: Thu, 15 Dec 2016 12:23:50 +0100
Subject: [PATCH] Add grammar rules for new constraint syntax

---
 grammar/basic-grammar.xml                   |  2 +-
 grammar/commands.xml                        | 45 ++++++++++++++++++++-
 tools/grammar/src/test/resources/cypher.txt | 13 ++++++
 3 files changed, 57 insertions(+), 3 deletions(-)

diff --git a/grammar/basic-grammar.xml b/grammar/basic-grammar.xml
index dbdd58f799..decbaddd0c 100644
--- a/grammar/basic-grammar.xml
+++ b/grammar/basic-grammar.xml
@@ -134,7 +134,7 @@
     </alt>
   </production>
 
-  <production name="RelType" rr:inline="true" oc:legacy="true">
+  <production name="RelType" rr:inline="true">
     :<non-terminal ref="RelTypeName"/>
   </production>
 
diff --git a/grammar/commands.xml b/grammar/commands.xml
index 7b8161fa68..42b331fb0a 100644
--- a/grammar/commands.xml
+++ b/grammar/commands.xml
@@ -31,7 +31,7 @@
   xmlns:rr="http://opencypher.org/railroad"
   xmlns:oc="http://opencypher.org/opencypher">
 
-  <production name="Command" rr:inline="true" oc:legacy="true">
+  <production name="Command" rr:inline="true">
     <alt>
       <non-terminal ref="CreateIndex"/>
       <non-terminal ref="DropIndex"/>
@@ -44,10 +44,51 @@
 
       <non-terminal ref="CreateRelationshipPropertyExistenceConstraint"/>
       <non-terminal ref="DropRelationshipPropertyExistenceConstraint"/>
+
+      <non-terminal ref="CreateConstraint"/>
+      <non-terminal ref="DropConstraint"/>
+    </alt>
+  </production>
+
+  <!-- / 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"/>
+  </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>
+
+  <production name="ConstraintExpression">
+    <alt>
+      <non-terminal ref="NodePropertyUniquenessConstraint"/>
+      <non-terminal ref="PropertyExistenceConstraint"/>
     </alt>
   </production>
 
-  <!-- / COMMANDS \ -->
+  <production name="NodePropertyUniquenessConstraint">
+    UNIQUE &SP; <non-terminal ref="PropertyExpression"/> <repeat>&WS; , &WS; <non-terminal ref="PropertyExpression"/></repeat>
+  </production>
+
+  <production name="PropertyExistenceConstraint">
+    exists ( <non-terminal ref="PropertyExpression"/> )
+  </production>
+
+  <!-- / LEGACY COMMANDS \ -->
 
   <production name="CreateUniqueConstraint" rr:inline="true" oc:legacy="true">
     CREATE &SP; <non-terminal ref="UniqueConstraint"/>
diff --git a/tools/grammar/src/test/resources/cypher.txt b/tools/grammar/src/test/resources/cypher.txt
index bf6af6b0f2..675c9ef4cc 100644
--- a/tools/grammar/src/test/resources/cypher.txt
+++ b/tools/grammar/src/test/resources/cypher.txt
@@ -178,3 +178,16 @@ RETURN .0020123§
 RETURN 10101.0020123§
 RETURN 10101.4§
 RETURN 99882.04000§
+CREATE CONSTRAINT foo
+FOR (p:Person)
+REQUIRE UNIQUE p.name§
+CREATE CONSTRAINT bar
+FOR (p:Person)
+REQUIRE UNIQUE p.name, p.email§
+CREATE CONSTRAINT baz
+FOR (p:Person)
+REQUIRE exists(p.name)§
+CREATE CONSTRAINT cru
+FOR ()-[r:REL]-()
+REQUIRE exists(r.property)§
+DROP CONSTRAINT foo_bar_baz§