Add expr.ExperimentalPipes() config

conf/config.go

@@ -22,6 +22,7 @@ type Config struct {
 	ConstFns    map[string]reflect.Value
 	Visitors    []ast.Visitor
 	Functions   map[string]*builtin.Function
+	Pipes       bool
 }
 
 // CreateNew creates new config with default values.

expr.go

@@ -130,6 +130,13 @@ func Function(name string, fn func(params ...interface{}) (interface{}, error),
 	}
 }
 
+// ExperimentalPipes enables pipes syntax.
+func ExperimentalPipes() Option {
+	return func(c *conf.Config) {
+		c.Pipes = true
+	}
+}
+
 // Compile parses and compiles given input expression to bytecode program.
 func Compile(input string, ops ...Option) (*vm.Program, error) {
 	config := conf.CreateNew()
@@ -146,7 +153,11 @@ func Compile(input string, ops ...Option) (*vm.Program, error) {
 		})
 	}
 
-	tree, err := parser.Parse(input)
+	parseConfig := parser.Config{
+		Pipes: config.Pipes,
+	}
+
+	tree, err := parser.ParseWithConfig(input, parseConfig)
 	if err != nil {
 		return nil, err
 	}

parser/parser.go

@@ -77,6 +77,7 @@ type parser struct {
 	pos     int
 	err     *file.Error
 	depth   int // closure call depth
+	pipes   bool
 }
 
 type Tree struct {
@@ -84,7 +85,15 @@ type Tree struct {
 	Source *file.Source
 }
 
+type Config struct {
+	Pipes bool
+}
+
 func Parse(input string) (*Tree, error) {
+	return ParseWithConfig(input, Config{})
+}
+
+func ParseWithConfig(input string, config Config) (*Tree, error) {
 	source := file.NewSource(input)
 
 	tokens, err := Lex(source)
@@ -95,6 +104,7 @@ func Parse(input string) (*Tree, error) {
 	p := &parser{
 		tokens:  tokens,
 		current: tokens[0],
+		pipes:   config.Pipes,
 	}
 
 	node := p.parseExpression(0)
@@ -592,6 +602,11 @@ func (p *parser) parsePostfixExpression(node Node) Node {
 }
 
 func (p *parser) parsePipe(node Node) Node {
+	if !p.pipes {
+		p.error("enable Pipes via expr.ExperimentalPipes()")
+		return &NilNode{}
+	}
+
 	identifier := p.current
 	p.expect(Identifier)
 

parser/parser_test.go

@@ -453,7 +453,7 @@ func TestParse(t *testing.T) {
 					&BoolNode{Value: true}}}},
 	}
 	for _, test := range parseTests {
-		actual, err := parser.Parse(test.input)
+		actual, err := parser.ParseWithConfig(test.input, parser.Config{Pipes: true})
 		if err != nil {
 			t.Errorf("%s:\n%v", test.input, err)
 			continue
@@ -657,7 +657,7 @@ func TestParse_pipe_operator(t *testing.T) {
 									Property: &StringNode{Value: "foo"},
 								}}}}}}}}
 
-	actual, err := parser.Parse(input)
+	actual, err := parser.ParseWithConfig(input, parser.Config{Pipes: true})
 	require.NoError(t, err)
 	assert.Equal(t, Dump(expect), Dump(actual.Node))
 }

test/pipes/pipes_test.go

@@ -37,7 +37,7 @@ func TestPipes(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.input, func(t *testing.T) {
-			program, err := expr.Compile(test.input, expr.Env(env))
+			program, err := expr.Compile(test.input, expr.Env(env), expr.ExperimentalPipes())
 			require.NoError(t, err)
 
 			out, err := expr.Run(program, env)
@@ -48,7 +48,7 @@ func TestPipes(t *testing.T) {
 }
 
 func TestPipes_map_filter(t *testing.T) {
-	program, err := expr.Compile(`1..9 | map(# + 1) | filter(# % 2 == 0)`)
+	program, err := expr.Compile(`1..9 | map(# + 1) | filter(# % 2 == 0)`, expr.ExperimentalPipes())
 	require.NoError(t, err)
 
 	out, err := expr.Run(program, nil)

test/time/time_test.go

@@ -120,15 +120,15 @@ func TestTime_date(t *testing.T) {
 		want  time.Time
 	}{
 		{
-			`'2017-10-23' | date()`,
+			`date('2017-10-23')`,
 			time.Date(2017, 10, 23, 0, 0, 0, 0, time.UTC),
 		},
 		{
-			`'24.11.1987 20:30' | date("02.01.2006 15:04", "Europe/Zurich")`,
+			`date('24.11.1987 20:30', "02.01.2006 15:04", "Europe/Zurich")`,
 			time.Date(1987, 11, 24, 20, 30, 0, 0, time.FixedZone("Europe/Zurich", 3600)),
 		},
 		{
-			`'24.11.1987 20:30 MSK' | date("02.01.2006 15:04 MST", "Europe/Zurich")`,
+			`date('24.11.1987 20:30 MSK', "02.01.2006 15:04 MST", "Europe/Zurich")`,
 			time.Date(1987, 11, 24, 20, 30, 0, 0, time.FixedZone("MSK", 0)),
 		},
 	}