Remove support for the legacy lambda syntax.

This fixes #664.

0.18.0-release-notes.md

@@ -3,6 +3,8 @@ This is the draft release notes for 0.18.0, scheduled to be released around
 
 # Breaking changes
 
+-   All features deprecated in 0.17.0 have been removed.
+
 -   Within double quotes, `\x` followed by two hexadecimal digits and `\`
     followed by three octal digits now encode an individual byte, rather than a
     codepoint.

pkg/edit/init.elv

@@ -3,7 +3,7 @@ set after-command = [
   # as a convenience for prompt functions. Note: The first time this is run is after
   # shell.sourceRC() finishes so the initial value of command-duration is the time
   # to execute the user's interactive configuration script.
-  [m]{
+  {|m|
     set command-duration = $m[duration]
   }
 ]

pkg/eval/compile_value.go

@@ -367,9 +367,6 @@ func (op outputCaptureOp) exec(fm *Frame) ([]interface{}, Exception) {
 }
 
 func (cp *compiler) lambda(n *parse.Primary) valuesOp {
-	if n.LegacyLambda {
-		cp.deprecate(n, "legacy lambda syntax is deprecated; migrate scripts with https://go.elv.sh/u0.17", 17)
-	}
 	// Parse signature.
 	var (
 		argNames      []string

pkg/eval/compile_value_test.go

@@ -220,7 +220,3 @@ func TestClosure(t *testing.T) {
 		That("{|@a @b| }").DoesNotCompile(),
 	)
 }
-
-func TestClosure_LegacySyntaxIsDeprecated(t *testing.T) {
-	testCompileTimeDeprecation(t, "a = []{ }", "legacy lambda syntax is deprecated", 17)
-}

pkg/parse/parse.go

@@ -493,8 +493,6 @@ type Primary struct {
 	node
 	ExprCtx ExprCtx
 	Type    PrimaryType
-	// Legacy lambda uses [args]{ body } instead of { |args| body }
-	LegacyLambda bool
 	// The unquoted string value. Valid for Bareword, SingleQuoted,
 	// DoubleQuoted, Variable, Wildcard and Tilde.
 	Value    string
@@ -828,45 +826,38 @@ items:
 	if !parseSep(pn, ps, ']') {
 		ps.error(errShouldBeRBracket)
 	}
-	if parseSep(pn, ps, '{') {
-		pn.LegacyLambda = true
-		pn.lambda(ps)
-	} else {
-		if loneAmpersand || len(pn.MapPairs) > 0 {
-			if len(pn.Elements) > 0 {
-				// TODO(xiaq): Add correct position information.
-				ps.error(errBothElementsAndPairs)
-			}
-			pn.Type = Map
-		} else {
-			pn.Type = List
+	if loneAmpersand || len(pn.MapPairs) > 0 {
+		if len(pn.Elements) > 0 {
+			// TODO(xiaq): Add correct position information.
+			ps.error(errBothElementsAndPairs)
 		}
+		pn.Type = Map
+	} else {
+		pn.Type = List
 	}
 }
 
 // lambda parses a lambda expression. The opening brace has been seen.
 func (pn *Primary) lambda(ps *parser) {
 	pn.Type = Lambda
-	if !pn.LegacyLambda {
+	parseSpacesAndNewlines(pn, ps)
+	if parseSep(pn, ps, '|') {
 		parseSpacesAndNewlines(pn, ps)
-		if parseSep(pn, ps, '|') {
+	items:
+		for {
+			r := ps.peek()
+			switch {
+			case r == '&':
+				ps.parse(&MapPair{}).addTo(&pn.MapPairs, pn)
+			case startsCompound(r, NormalExpr):
+				ps.parse(&Compound{}).addTo(&pn.Elements, pn)
+			default:
+				break items
+			}
 			parseSpacesAndNewlines(pn, ps)
-		items:
-			for {
-				r := ps.peek()
-				switch {
-				case r == '&':
-					ps.parse(&MapPair{}).addTo(&pn.MapPairs, pn)
-				case startsCompound(r, NormalExpr):
-					ps.parse(&Compound{}).addTo(&pn.Elements, pn)
-				default:
-					break items
-				}
-				parseSpacesAndNewlines(pn, ps)
-			}
-			if !parseSep(pn, ps, '|') {
-				ps.error(errShouldBePipe)
-			}
+		}
+		if !parseSep(pn, ps, '|') {
+			ps.error(errShouldBePipe)
 		}
 	}
 	ps.parse(&Chunk{}).addAs(&pn.Chunk, pn)

pkg/parse/parse_test.go

@@ -343,49 +343,23 @@ var testCases = []struct {
 		),
 	},
 	{
-		name: "lambda",
-		code: "a []{} [ ]{ } []{ echo 233 } [ x y ]{puts $x $y} { put haha}",
-		node: &Chunk{},
-		want: a(
-			ast{"Compound/Indexing/Primary", fs{
-				"Type": Lambda, "LegacyLambda": true, "Elements": []ast{}, "Chunk": "",
-			}},
-			ast{"Compound/Indexing/Primary", fs{
-				"Type": Lambda, "LegacyLambda": true, "Elements": []ast{}, "Chunk": " ",
-			}},
-			ast{"Compound/Indexing/Primary", fs{
-				"Type": Lambda, "LegacyLambda": true, "Elements": []ast{}, "Chunk": " echo 233 ",
-			}},
-			ast{"Compound/Indexing/Primary", fs{
-				"Type": Lambda, "LegacyLambda": true, "Elements": []string{"x", "y"}, "Chunk": "puts $x $y",
-			}},
-			ast{"Compound/Indexing/Primary", fs{
-				"Type": Lambda, "Elements": []ast{}, "Chunk": "put haha",
-			}},
-		),
-	},
-	{
-		name: "new-style lambda with arguments and options",
-		code: "{|a b &k=v|}",
+		name: "lambda without signature",
+		code: "{ echo}",
 		node: &Primary{},
 		want: ast{"Primary", fs{
-			"Type":         Lambda,
-			"LegacyLambda": false,
-			"Elements":     []string{"a", "b"},
-			"MapPairs":     []string{"&k=v"},
-			"Chunk":        "",
+			"Type":  Lambda,
+			"Chunk": "echo",
 		}},
 	},
 	{
-		name: "legacy lambda with arguments and options",
-		code: "[a b &k=v]{}",
+		name: "new-style lambda with arguments and options",
+		code: "{|a b &k=v| echo}",
 		node: &Primary{},
 		want: ast{"Primary", fs{
-			"Type":         Lambda,
-			"LegacyLambda": true,
-			"Elements":     []string{"a", "b"},
-			"MapPairs":     []string{"&k=v"},
-			"Chunk":        "",
+			"Type":     Lambda,
+			"Elements": []string{"a", "b"},
+			"MapPairs": []string{"&k=v"},
+			"Chunk":    " echo",
 		}},
 	},
 	{

pkg/parse/pprint_test.go

@@ -13,19 +13,19 @@ var pprintASTTests = tt.Table{
 	tt.Args(n).Rets(
 		`Chunk
   Pipeline/Form
-    Compound/Indexing/Primary ExprCtx=CmdExpr Type=Bareword LegacyLambda=false Value="ls"
+    Compound/Indexing/Primary ExprCtx=CmdExpr Type=Bareword Value="ls"
     Compound ExprCtx=NormalExpr
       Indexing ExprCtx=NormalExpr
-        Primary ExprCtx=NormalExpr Type=Variable LegacyLambda=false Value="x"
-        Array/Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword LegacyLambda=false Value="0"
+        Primary ExprCtx=NormalExpr Type=Variable Value="x"
+        Array/Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword Value="0"
       Indexing ExprCtx=NormalExpr
-        Primary ExprCtx=NormalExpr Type=Variable LegacyLambda=false Value="y"
-        Array/Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword LegacyLambda=false Value="1"
+        Primary ExprCtx=NormalExpr Type=Variable Value="y"
+        Array/Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword Value="1"
   Pipeline/Form
-    Compound/Indexing/Primary ExprCtx=CmdExpr Type=Bareword LegacyLambda=false Value="echo"
-    Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword LegacyLambda=false Value="done"
+    Compound/Indexing/Primary ExprCtx=CmdExpr Type=Bareword Value="echo"
+    Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword Value="done"
     Redir Mode=Write RightIsFd=false
-      Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword LegacyLambda=false Value="/redir-dest"
+      Compound/Indexing/Primary ExprCtx=NormalExpr Type=Bareword Value="/redir-dest"
 `),
 }