Update existential subquery CIP

grammar/basic-grammar.xml

@@ -312,6 +312,7 @@
       <non-terminal ref="RelationshipsPattern"/>
       <non-terminal ref="ParenthesizedExpression"/>
       <non-terminal ref="FunctionInvocation"/>
+      <non-terminal ref="ExistentialSubquery"/>
       &var;
     </alt>
   </production>
@@ -387,13 +388,20 @@
   </production>
 
   <production name="FunctionName" rr:inline="true">
+    <non-terminal ref="Namespace" rr:title="function namespace"/>
+    <non-terminal ref="SymbolicName" rr:title="function name"/>
+  </production>
+
+  <production name="ExistentialSubquery">
+    EXISTS &WS; { &WS;
     <alt>
+      <non-terminal ref="RegularQuery" rr:title="full existential subquery"/>
       <seq>
-        <non-terminal ref="Namespace" rr:title="function namespace"/>
-        <non-terminal ref="SymbolicName" rr:title="function name"/>
+        <non-terminal ref="Pattern"/>
+        <opt>&WS; <non-terminal ref="Where"/></opt>
       </seq>
-      EXISTS
     </alt>
+    &WS; }
   </production>
 
   <production name="ExplicitProcedureInvocation">
@@ -433,7 +441,7 @@
     [ &WS;
       <opt><non-terminal ref="Variable"/> &WS; = &WS;</opt>
       <non-terminal ref="RelationshipsPattern"/> &WS;
-      <opt>WHERE &WS; <non-terminal ref="Expression"/> &WS;</opt>
+      <opt><non-terminal ref="Where"/> &WS;</opt>
       | &WS; <non-terminal ref="Expression"/> &WS;
     ]
   </production>
@@ -447,14 +455,14 @@
 
   <production name="CaseExpression">
     <alt>
-      <seq>CASE <repeat min="1">&WS; <non-terminal ref="CaseAlternatives"/></repeat></seq>
-      <seq>CASE &WS; &expr; <repeat min="1">&WS; <non-terminal ref="CaseAlternatives"/></repeat></seq>
+      <seq>CASE <repeat min="1">&WS; <non-terminal ref="CaseAlternative"/></repeat></seq>
+      <seq>CASE &WS; &expr; <repeat min="1">&WS; <non-terminal ref="CaseAlternative"/></repeat></seq>
     </alt>
     <opt>&WS; ELSE &WS; &expr;</opt>
     &WS; END
   </production>
 
-  <production name="CaseAlternatives" rr:inline="true">
+  <production name="CaseAlternative" rr:inline="true">
     WHEN &WS; &expr; &WS; THEN &WS; &expr;
   </production>
 

tck/features/clauses/match-where/MatchWhere5.feature

@@ -85,7 +85,7 @@ Feature: MatchWhere5 - Filter on predicate resulting in null
     When executing query:
       """
       MATCH (:Root {name: 'x'})-->(i:TextNode)
-      WHERE i.var > 'te' AND exists(i.var)
+      WHERE i.var > 'te' AND i.var IS NOT NULL
       RETURN i
       """
     Then the result should be, in any order:
@@ -106,7 +106,7 @@ Feature: MatchWhere5 - Filter on predicate resulting in null
     When executing query:
       """
       MATCH (:Root {name: 'x'})-->(i)
-      WHERE i.var > 'te' OR exists(i.var)
+      WHERE i.var > 'te' OR i.var IS NOT NULL
       RETURN i
       """
     Then the result should be, in any order:

tck/features/clauses/remove/Remove1.feature

@@ -40,7 +40,7 @@ Feature: Remove1 - Remove a Property
       """
       MATCH (n)
       REMOVE n.num
-      RETURN exists(n.num) AS still_there
+      RETURN n.num IS NOT NULL AS still_there
       """
     Then the result should be, in any order:
       | still_there |
@@ -76,7 +76,7 @@ Feature: Remove1 - Remove a Property
       """
       MATCH ()-[r]->()
       REMOVE r.num
-      RETURN exists(r.num) AS still_there
+      RETURN r.num IS NOT NULL AS still_there
       """
     Then the result should be, in any order:
       | still_there |

tck/features/clauses/return/Return3.feature

@@ -39,11 +39,11 @@ Feature: Return3 - Return multiple expressions (if column order correct)
     When executing query:
       """
       MATCH (a)
-      RETURN exists(a.id), a IS NOT NULL
+      RETURN a.id IS NOT NULL AS a, a IS NOT NULL AS b
       """
     Then the result should be, in any order:
-      | exists(a.id) | a IS NOT NULL |
-      | false        | true          |
+      | a     | b    |
+      | false | true |
     And no side effects
 
   Scenario: [2] Returning multiple node property values

tck/features/clauses/with-where/WithWhere5.feature

@@ -88,7 +88,7 @@ Feature: WithWhere5 - Filter on predicate resulting in null
       """
       MATCH (:Root {name: 'x'})-->(i:TextNode)
       WITH i
-      WHERE i.var > 'te' AND exists(i.var)
+      WHERE i.var > 'te' AND i.var IS NOT NULL
       RETURN i
       """
     Then the result should be, in any order:
@@ -110,7 +110,7 @@ Feature: WithWhere5 - Filter on predicate resulting in null
       """
       MATCH (:Root {name: 'x'})-->(i)
       WITH i
-      WHERE i.var > 'te' OR exists(i.var)
+      WHERE i.var > 'te' OR i.var IS NOT NULL
       RETURN i
       """
     Then the result should be, in any order:

tck/features/expressions/comparison/Comparison2.feature

@@ -41,7 +41,7 @@ Feature: Comparison2 - Half-bounded Range
     When executing query:
       """
       MATCH (:Root)-->(i:Child)
-      WHERE exists(i.var) AND i.var > 'x'
+      WHERE i.var IS NOT NULL AND i.var > 'x'
       RETURN i.var
       """
     Then the result should be, in any order:
@@ -60,7 +60,7 @@ Feature: Comparison2 - Half-bounded Range
     When executing query:
       """
       MATCH (:Root)-->(i:Child)
-      WHERE NOT exists(i.var) OR i.var > 'x'
+      WHERE i.var IS NULL OR i.var > 'x'
       RETURN i.var
       """
     Then the result should be, in any order: