From 419ad41ec6b212d8c827b838c68434dd065caf03 Mon Sep 17 00:00:00 2001
From: Aravind Rao <palimar@google.com>
Date: Tue, 2 May 2017 11:23:27 -0700
Subject: [PATCH] Added Reification Clause

---
 bql/grammar/grammar.go      | 14 ++++++++++++++
 bql/grammar/grammar_test.go | 13 +++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/bql/grammar/grammar.go b/bql/grammar/grammar.go
index 6e847129..18cc1dcb 100644
--- a/bql/grammar/grammar.go
+++ b/bql/grammar/grammar.go
@@ -761,6 +761,7 @@ func BQL() *Grammar {
 					NewTokenType(lexer.ItemNode),
 					NewSymbol("CONSTRUCT_PREDICATE"),
 					NewSymbol("CONSTRUCT_OBJECT"),
+					NewSymbol("REIFICATION_CLAUSE"),
 					NewSymbol("MORE_CONSTRUCT_TRIPLES"),
 				},
 			},
@@ -769,6 +770,7 @@ func BQL() *Grammar {
 					NewTokenType(lexer.ItemBlankNode),
 					NewSymbol("CONSTRUCT_PREDICATE"),
 					NewSymbol("CONSTRUCT_OBJECT"),
+					NewSymbol("REIFICATION_CLAUSE"),
 					NewSymbol("MORE_CONSTRUCT_TRIPLES"),
 				},
 			},
@@ -777,6 +779,7 @@ func BQL() *Grammar {
 					NewTokenType(lexer.ItemBinding),
 					NewSymbol("CONSTRUCT_PREDICATE"),
 					NewSymbol("CONSTRUCT_OBJECT"),
+					NewSymbol("REIFICATION_CLAUSE"),
 					NewSymbol("MORE_CONSTRUCT_TRIPLES"),
 				},
 			},
@@ -815,6 +818,17 @@ func BQL() *Grammar {
 				},
 			},
 		},
+		"REIFICATION_CLAUSE": []*Clause{
+			{
+				Elements: []Element{
+					NewTokenType(lexer.ItemSemicolon),
+					NewSymbol("CONSTRUCT_PREDICATE"),
+					NewSymbol("CONSTRUCT_OBJECT"),
+					NewSymbol("REIFICATION_CLAUSE"),
+				},
+			},
+			{},
+		},
 		"MORE_CONSTRUCT_TRIPLES": []*Clause{
 			{
 				Elements: []Element{
diff --git a/bql/grammar/grammar_test.go b/bql/grammar/grammar_test.go
index 7c3c5d02..c3ea3da2 100644
--- a/bql/grammar/grammar_test.go
+++ b/bql/grammar/grammar_test.go
@@ -125,6 +125,15 @@ func TestAcceptByParse(t *testing.T) {
 			    _:v "_object"@[] ?o} into ?a from ?b where {?n "_subject"@[] ?s.
 									?n "_predicate"@[] ?p.
 									?n "_object"@[] ?o};`,
+		`construct {?s "predicate_1"@[] ?o1;
+			       "predicate_2"@[] ?o2} into ?a from ?b where {?s "old_predicate_1"@[,] ?o1.
+									    ?s "old_predicate_2"@[,] ?o2};`,
+
+		`construct {?s "predicate_1"@[] ?o1;
+			       "predicate_2"@[] ?o2.
+		            ?s "predicate_3"@[] ?o3} into ?a from ?b where {?s "old_predicate_1"@[,] ?o1.
+									    ?s "old_predicate_2"@[,] ?o2.
+									    ?s "old_predicate_3"@[,] ?o3};`,
 	}
 	p, err := NewParser(BQL())
 	if err != nil {
@@ -229,6 +238,10 @@ func TestRejectByParse(t *testing.T) {
 		// Construct clause with badly formed triple.
 		`construct {?s ?p ?o.
 		            _:v "some_pred"@[]} into ?a from ?b where {?s "foo"@[,] ?o};`,
+		// Construct clause with badly formed reification clause.
+		`construct {?s "predicate_1"@[] ?o1;
+		            ?s "predicate_2"@[] ?o2} into ?a from ?b where {?s "old_predicate_1"@[,] ?o1.
+									    ?s "old_predicate_2"@[,] ?o2};`,
 
 	}
 	p, err := NewParser(BQL())