From 9988ebde6f89dd5ae10f7ecdd76939e7ef95cee7 Mon Sep 17 00:00:00 2001
From: David BF <burretfresket@gmail.com>
Date: Fri, 2 Oct 2020 19:35:17 +0200
Subject: [PATCH] Add Regexp FILTER operator (#558)

---
 pkg/compiler/compiler_filter_test.go | 35 ++++++++++++++++++++++++++++
 pkg/compiler/visitor.go              |  6 +++++
 2 files changed, 41 insertions(+)

diff --git a/pkg/compiler/compiler_filter_test.go b/pkg/compiler/compiler_filter_test.go
index f46dba69..96c3ca8b 100644
--- a/pkg/compiler/compiler_filter_test.go
+++ b/pkg/compiler/compiler_filter_test.go
@@ -46,6 +46,41 @@ func TestForFilter(t *testing.T) {
 		So(string(out), ShouldEqual, `[2,3,3]`)
 	})
 
+	Convey("Should compile query with a regexp FILTER statement", t, func() {
+		c := compiler.New()
+
+		p, err := c.Compile(`
+			LET users = [
+				{
+					age: 31,
+					gender: "m",
+					name: "Josh"
+				},
+				{
+					age: 29,
+					gender: "f",
+					name: "Mary"
+				},
+				{
+					age: 36,
+					gender: "m",
+					name: "Peter"
+				}
+			]
+			FOR u IN users
+				FILTER u.name =~ "r"
+				RETURN u
+		`)
+
+		So(err, ShouldBeNil)
+
+		out, err := p.Run(context.Background())
+
+		So(err, ShouldBeNil)
+
+		So(string(out), ShouldEqual, `[{"age":29,"gender":"f","name":"Mary"},{"age":36,"gender":"m","name":"Peter"}]`)
+	})
+
 	Convey("Should compile query with multiple FILTER statements", t, func() {
 		c := compiler.New()
 
diff --git a/pkg/compiler/visitor.go b/pkg/compiler/visitor.go
index 85d13d8a..b64e664b 100644
--- a/pkg/compiler/visitor.go
+++ b/pkg/compiler/visitor.go
@@ -434,6 +434,12 @@ func (v *visitor) doVisitFilterClause(ctx *fql.FilterClauseContext, scope *scope
 			return operators.NewEqualityOperator(v.getSourceMap(ctx), left, right, equalityOp.GetText())
 		}
 
+		regexpOp := exp.RegexpOperator()
+
+		if regexpOp != nil {
+			return operators.NewRegexpOperator(v.getSourceMap(ctx), left, right, regexpOp.GetText())
+		}
+
 		logicalAndOp := exp.LogicalAndOperator()
 
 		if logicalAndOp != nil {