Experimental support for MATCH as expr.

- Still doesn't allow edge as first part of a non-nested pattern
- Requires parens around entire MATCH expression

Author: jpschorr

partiql-ast/src/ast.rs

@@ -208,6 +208,8 @@ pub enum Expr {
     Like(AstNode<Like>),
     Between(AstNode<Between>),
     In(AstNode<In>),
+    /// <expr> MATCH <graph_pattern>
+    GraphMatch(AstNode<GraphMatch>),
     Case(AstNode<Case>),
     /// Constructors
     Struct(AstNode<Struct>),
@@ -535,8 +537,6 @@ pub enum FromClause {
     FromLet(AstNode<FromLet>),
     /// <from_source> JOIN \[INNER | LEFT | RIGHT | FULL\] <from_source> ON <expr>
     Join(AstNode<Join>),
-    /// <expr> MATCH <graph_pattern>
-    GraphMatch(AstNode<GraphMatch>),
 }
 
 #[derive(Clone, Debug, PartialEq)]
@@ -606,7 +606,7 @@ pub struct GraphMatch {
 ///
 /// Fig. 5. Table of edge patterns:
 /// https://arxiv.org/abs/2112.06217
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum GraphMatchDirection {
     Left,
@@ -633,7 +633,7 @@ pub enum GraphMatchPatternPart {
 }
 
 /// A quantifier for graph edges or patterns. (e.g., the `{2,5}` in `MATCH (x)->{2,5}(y)`)
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub struct GraphMatchQuantifier {
     pub lower: u32,
@@ -649,7 +649,7 @@ pub struct GraphMatchQuantifier {
 ///
 /// Fig. 7. Table of restrictors:
 /// https://arxiv.org/abs/2112.06217
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum GraphMatchRestrictor {
     Trail,
@@ -712,7 +712,7 @@ pub struct GraphMatchPattern {
 ///
 /// Fig. 8. Table of restrictors:
 /// https://arxiv.org/abs/2112.06217
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
 pub enum GraphMatchSelector {
     AnyShortest,

partiql-parser/src/parse/mod.rs

@@ -684,111 +684,122 @@ mod tests {
 
         #[test]
         fn no_labels() {
-            parse!(r#"SELECT 1 FROM my_graph MATCH ()"#);
-            parse!(r#"SELECT 1 FROM my_graph MATCH () WHERE contains_value('1')"#);
-            parse!(r#"SELECT x.info AS info FROM my_graph MATCH (x) WHERE x.name LIKE 'foo'"#);
-            //parse!(r#"SELECT 1 FROM g MATCH -[]-> "#);
+            parse!(r#"SELECT 1 FROM (my_graph MATCH ())"#);
+            parse!(r#"SELECT 1 FROM (my_graph MATCH ()) WHERE contains_value('1')"#);
+            parse!(r#"SELECT x.info AS info FROM (my_graph MATCH (x)) WHERE x.name LIKE 'foo'"#);
+            // TODO fails due to edge first
+            // parse!(r#"SELECT 1 FROM (g MATCH -[]->) "#);
+        }
+
+        #[test]
+        fn lone_match_expr() {
+            parse!(r#"(MyGraph MATCH (x))"#);
+            parse!(r#"(MyGraph MATCH (x), (y) )"#);
+            // TODO fails due to edge first
+            //parse!(r#"(MyGraph MATCH (x), -[u]-> )"#);
         }
 
         #[test]
         fn labelled_nodes() {
-            parse!(r#"SELECT x AS target FROM my_graph MATCH (x:Label) WHERE x.has_data = true"#);
+            parse!(r#"SELECT x AS target FROM (my_graph MATCH (x:Label)) WHERE x.has_data = true"#);
         }
 
         #[test]
         fn edges() {
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) -[e:E]-> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) -> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) ~[e:E]~ (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) ~ (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <-[e:E]- (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <- (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) ~[e:E]~> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) ~> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <~[e:E]~ (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <~ (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <-[e:E]-> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) <-> (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) -[e:E]- (b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A) - (b:B)"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) -[e:E]-> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) -> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) ~[e:E]~ (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) ~ (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <-[e:E]- (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <- (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) ~[e:E]~> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) ~> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <~[e:E]~ (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <~ (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <-[e:E]-> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) <-> (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) -[e:E]- (b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A) - (b:B))"#);
         }
 
         #[test]
         fn quantifiers() {
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)-[:edge]->*(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)<-[:edge]-+(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)~[:edge]~{5,}(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)-[e:edge]-{2,6}(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)->*(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)<-+(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)~{5,}(b:B)"#);
-            parse!(r#"SELECT a,b FROM g MATCH (a:A)-{2,6}(b:B)"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)-[:edge]->*(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)<-[:edge]-+(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)~[:edge]~{5,}(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)-[e:edge]-{2,6}(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)->*(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)<-+(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)~{5,}(b:B))"#);
+            parse!(r#"SELECT a,b FROM (g MATCH (a:A)-{2,6}(b:B))"#);
         }
 
         #[test]
         fn patterns() {
             parse!(
-                r#"SELECT the_a.name AS src, the_b.name AS dest FROM my_graph MATCH (the_a:a) -[the_y:y]-> (the_b:b) WHERE the_y.score > 10"#
+                r#"SELECT the_a.name AS src, the_b.name AS dest FROM (my_graph MATCH (the_a:a) -[the_y:y]-> (the_b:b)) WHERE the_y.score > 10"#
             );
-            parse!(r#""SELECT a,b FROM g MATCH (a)-[:has]->()-[:contains]->(b)""#);
+            parse!(r#""SELECT a,b FROM (g MATCH (a)-[:has]->()-[:contains]->(b))""#);
             parse!(r#"SELECT a,b FROM (g MATCH (a) -[:has]-> (x), (x)-[:contains]->(b))"#);
         }
 
         #[test]
         fn path_var() {
-            parse!(r#"SELECT a,b FROM g MATCH p = (a:A) -[e:E]-> (b:B)"#);
+            parse!(r#"SELECT a,b FROM (g MATCH p = (a:A) -[e:E]-> (b:B))"#);
         }
 
         #[test]
         fn paranthesized() {
-            parse!(r#"SELECT a,b FROM g MATCH [(a:A)-[e:Edge]->(b:A) WHERE a.owner=b.owner]{2,5}"#);
-            parse!(r#"SELECT a,b FROM g MATCH pathVar = (a:A)[()-[e:Edge]->()]{1,3}(b:B)"#);
+            parse!(
+                r#"SELECT a,b FROM (g MATCH [(a:A)-[e:Edge]->(b:A) WHERE a.owner=b.owner]{2,5})"#
+            );
+            parse!(r#"SELECT a,b FROM (g MATCH pathVar = (a:A)[()-[e:Edge]->()]{1,3}(b:B))"#);
 
             // brackets
-            parse!(r#"SELECT a,b FROM g MATCH pathVar = (a:A)[-[e:Edge]->]*(b:B)"#);
+            parse!(r#"SELECT a,b FROM (g MATCH pathVar = (a:A)[-[e:Edge]->]*(b:B))"#);
             // parens
-            parse!(r#"SELECT a,b FROM g MATCH pathVar = (a:A)(-[e:Edge]->)*(b:B)"#);
+            parse!(r#"SELECT a,b FROM (g MATCH pathVar = (a:A)(-[e:Edge]->)*(b:B))"#);
         }
 
         #[test]
         fn filters() {
             parse!(
-                r#"SELECT u as banCandidate FROM g MATCH (p:Post Where p.isFlagged = true) <-[:createdPost]- (u:User WHERE u.isBanned = false AND u.karma < 20) -[:createdComment]->(c:Comment WHERE c.isFlagged = true) WHERE p.title LIKE '%considered harmful%'"#
+                r#"SELECT u as banCandidate FROM (g MATCH (p:Post Where p.isFlagged = true) <-[:createdPost]- (u:User WHERE u.isBanned = false AND u.karma < 20) -[:createdComment]->(c:Comment WHERE c.isFlagged = true)) WHERE p.title LIKE '%considered harmful%'"#
             );
         }
 
         #[test]
         fn restrictors() {
             parse!(
-                r#"SELECT p FROM g MATCH TRAIL p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH TRAIL p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH SIMPLE p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH SIMPLE p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH ACYCLIC p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH ACYCLIC p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
         }
 
         #[test]
         fn selectors() {
             parse!(
-                r#"SELECT p FROM g MATCH ANY SHORTEST p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH ANY SHORTEST p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH ALL SHORTEST p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH ALL SHORTEST p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH ANY p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH ANY p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH ANY 5 p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH ANY 5 p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH SHORTEST 5 p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH SHORTEST 5 p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
             parse!(
-                r#"SELECT p FROM g MATCH SHORTEST 5 GROUP p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha')"#
+                r#"SELECT p FROM (g MATCH SHORTEST 5 GROUP p = (a WHERE a.owner='Dave') -[t:Transfer]-> * (b WHERE b.owner='Aretha'))"#
             );
         }
 
@@ -799,10 +810,16 @@ mod tests {
             );
         }
 
+        #[test]
+        fn union() {
+            parse!(r#"(MyGraph MATCH (x)) UNION SELECT * FROM tbl1"#);
+            parse!(r#"SELECT * FROM tbl1 UNION (MyGraph MATCH (x))"#);
+        }
+
         #[test]
         fn etc() {
-            parse!("SELECT * FROM g MATCH ALL SHORTEST [ (x)-[e]->*(y) ]");
-            parse!("SELECT * FROM g MATCH ALL SHORTEST [ TRAIL (x)-[e]->*(y) ]");
+            parse!("SELECT * FROM (g MATCH ALL SHORTEST [ (x)-[e]->*(y) ])");
+            parse!("SELECT * FROM (g MATCH ALL SHORTEST [ TRAIL (x)-[e]->*(y) ])");
         }
     }