cue/parser: disallow deprecated language features in API

In the tool this was already the case for a long time.
This basically means that API operations will now
fail on deprectaed features whereas before they were
handled in compatibility mode. The parser.FromVersion
feature can be used to reenable these deprecated
features.

Issue cue-lang#1543

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: Ie40afd22143a46799373745cbeb4973a3f387487
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/546763
Reviewed-by: Paul Jolly <[email protected]>
Unity-Result: CUEcueckoo <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

Author: mpvl

cmd/cue/cmd/common.go

@@ -34,24 +34,19 @@ import (
 	"cuelang.org/go/cue/load"
 	"cuelang.org/go/cue/parser"
 	"cuelang.org/go/cue/token"
+	"cuelang.org/go/internal"
 	"cuelang.org/go/internal/core/adt"
 	"cuelang.org/go/internal/encoding"
 	"cuelang.org/go/internal/filetypes"
 	"cuelang.org/go/internal/value"
 )
 
-// Disallow
-// - block comments
-// - old-style field comprehensions
-// - space separator syntax
-const syntaxVersion = -1000 + 100*2 + 1
-
 var requestedVersion = os.Getenv("CUE_SYNTAX_OVERRIDE")
 
 var defaultConfig = config{
 	loadCfg: &load.Config{
 		ParseFile: func(name string, src interface{}) (*ast.File, error) {
-			version := syntaxVersion
+			version := internal.APIVersionSupported
 			if requestedVersion != "" {
 				switch {
 				case strings.HasPrefix(requestedVersion, "v0.1"):

cue/format/testdata/simplify.golden

@@ -32,7 +32,7 @@ quux: 5
 
 (x): "foo"
 
-a :: {
+a: {
 	foo: 2
 	...
 }

cue/format/testdata/simplify.input

@@ -34,7 +34,7 @@ a:
 
 (x): "foo"
 
-a :: {
+a: {
     [string]: _
     foo: 2
 }

cue/parser/interface.go

@@ -21,6 +21,7 @@ import (
 	"cuelang.org/go/cue/ast/astutil"
 	"cuelang.org/go/cue/errors"
 	"cuelang.org/go/cue/token"
+	"cuelang.org/go/internal"
 	"cuelang.org/go/internal/source"
 )
 
@@ -83,10 +84,6 @@ func FromVersion(version int) Option {
 	return func(p *parser) { p.version = version }
 }
 
-func version0(minor, patch int) int {
-	return -1000 + 100*minor + patch
-}
-
 // DeprecationError is a sentinel error to indicate that an error is
 // related to an unsupported old CUE syntax.
 type DeprecationError struct {
@@ -97,11 +94,19 @@ func (e *DeprecationError) Error() string {
 	return "try running `cue fix` (possibly with an earlier version, like v0.2.2) to upgrade"
 }
 
-// Latest specifies the latest version of the parser, effectively setting
-// the strictest implementation.
-const Latest = latest
+const (
+	// Latest specifies the latest version of the parser, effectively setting
+	// the strictest implementation.
+	Latest = latest
+
+	latest = -1000 + (100 * internal.MinorCurrent) + 0
+
+	// FullBackwardCompatibility enables all deprecated features that are
+	// currently still supported by the parser.
+	FullBackwardCompatibility = fullCompatibility
 
-const latest = -600
+	fullCompatibility = -1000
+)
 
 // FileOffset specifies the File position info to use.
 func FileOffset(pos int) Option {

cue/parser/parser.go

@@ -24,6 +24,7 @@ import (
 	"cuelang.org/go/cue/literal"
 	"cuelang.org/go/cue/scanner"
 	"cuelang.org/go/cue/token"
+	"cuelang.org/go/internal"
 	"cuelang.org/go/internal/astinternal"
 )
 
@@ -393,8 +394,12 @@ func (p *parser) next() {
 // assertV0 indicates the last version at which a certain feature was
 // supported.
 func (p *parser) assertV0(pos token.Pos, minor, patch int, name string) {
-	v := version0(minor, patch)
-	if p.version != 0 && p.version > v {
+	v := internal.Version(minor, patch)
+	base := p.version
+	if base == 0 {
+		base = internal.APIVersionSupported
+	}
+	if base > v {
 		p.errors = errors.Append(p.errors,
 			errors.Wrapf(&DeprecationError{v}, pos,
 				"use of deprecated %s (deprecated as of v0.%d.%d)", name, minor, patch+1))

cue/parser/parser_test.go

@@ -212,12 +212,12 @@ func TestParse(t *testing.T) {
 		`package k8s, import a "foo", import "bar/baz"`,
 	}, {
 		"collapsed fields",
-		`a: b:: c?: [Name=_]: d: 1
+		`a: #b: c?: [Name=_]: d: 1
 		"g\("en")"?: 4
 		 // job foo { bar: 1 } // TODO error after foo
 		 job: "foo": [_]: { bar: 1 }
 		`,
-		`a: {b :: {c?: {[Name=_]: {d: 1}}}}, "g\("en")"?: 4, job: {"foo": {[_]: {bar: 1}}}`,
+		`a: {#b: {c?: {[Name=_]: {d: 1}}}}, "g\("en")"?: 4, job: {"foo": {[_]: {bar: 1}}}`,
 	}, {
 		"identifiers",
 		`// 	$_: 1,

cue/testdata/compile/erralias.txtar

@@ -4,9 +4,6 @@
 [Y="foo"]: 3
 a:         Y
 
-"\(b)" :: 3
-b:        "foo"
-
 c: {}
 for x in c {a: E}
 
@@ -16,17 +13,13 @@ unreferenced alias or let clause X:
     ./in.cue:1:2
 a: reference "Y" not found:
     ./in.cue:4:12
-definitions not supported for interpolations:
-    ./in.cue:6:1
 for[].a: reference "E" not found:
-    ./in.cue:10:16
+    ./in.cue:7:16
 --- in.cue
 {
   let X#1 = {}
   ["foo"]: 3
   a: _|_(reference "Y" not found)
-  "\(〈0;b〉)": 3
-  b: "foo"
   c: {}
   for _, x in 〈0;c〉 {
     a: _|_(reference "E" not found)

cue/testdata/cycle/issue242.txtar

@@ -1,7 +1,5 @@
-# TODO: remove support for '::'; cuelang.org/issue/1543
-
 -- in.cue --
-size ::     2
+#size:     2
 #CellValue: 0 | 1 | 2 | 3
 cell: "0": "0": #CellValue
 cell: "0": "0": !=cell["0"]["1"]
@@ -100,7 +98,7 @@ Conjuncts:    191
 Disjuncts:    79
 -- out/eval --
 (struct){
-  size: (int){ 2 }
+  #size: (int){ 2 }
   #CellValue: (int){ |((int){ 0 }, (int){ 1 }, (int){ 2 }, (int){ 3 }) }
   cell: (struct){
     "0": (struct){
@@ -136,7 +134,7 @@ Disjuncts:    79
 -- out/compile --
 --- in.cue
 {
-  size:: 2
+  #size: 2
   #CellValue: (0|1|2|3)
   cell: {
     "0": {

internal/encoding/encoding_test.go

@@ -25,9 +25,10 @@ import (
 
 func TestValidate(t *testing.T) {
 	testCases := []struct {
-		form build.Form
-		in   string
-		err  string
+		form   build.Form
+		in     string
+		err    string
+		compat bool
 	}{{
 		form: "data",
 		in: `
@@ -40,7 +41,7 @@ func TestValidate(t *testing.T) {
 	}, {
 		form: "graph",
 		in: `
-		X=3
+		let X = 3
 		a: X
 		"b-b": 3
 		s: a
@@ -51,12 +52,12 @@ func TestValidate(t *testing.T) {
 		{form: "data", err: "references", in: `a: a`},
 		{form: "data", err: "expressions", in: `a: 1 + 3`},
 		{form: "data", err: "expressions", in: `a: 1 + 3`},
-		{form: "data", err: "definitions", in: `a :: 1`},
+		{form: "data", err: "definitions", in: `#a: 1`},
 		{form: "data", err: "constraints", in: `a: <1`},
 		{form: "data", err: "expressions", in: `a: !true`},
 		{form: "data", err: "expressions", in: `a: 1 | 2`},
 		{form: "data", err: "expressions", in: `a: 1 | *2`},
-		{form: "data", err: "references", in: `X=3, a: X`},
+		{form: "data", err: "references", in: `let X = 3, a: X`, compat: true},
 		{form: "data", err: "expressions", in: `2+2`},
 		{form: "data", err: "expressions", in: `"\(3)"`},
 		{form: "data", err: "expressions", in: `for x in [2] { a: 2 }`},
@@ -65,7 +66,11 @@ func TestValidate(t *testing.T) {
 	}
 	for _, tc := range testCases {
 		t.Run(path.Join(string(tc.form), tc.in), func(t *testing.T) {
-			f, err := parser.ParseFile("", tc.in, parser.ParseComments)
+			opts := []parser.Option{parser.ParseComments}
+			if tc.compat {
+				opts = append(opts, parser.FromVersion(-1000))
+			}
+			f, err := parser.ParseFile("", tc.in, opts...)
 			if err != nil {
 				t.Fatal(err)
 			}

internal/encoding/json/encode.go

@@ -24,6 +24,7 @@ import (
 	"cuelang.org/go/cue/errors"
 	"cuelang.org/go/cue/literal"
 	"cuelang.org/go/cue/token"
+	"cuelang.org/go/internal"
 	"cuelang.org/go/internal/astinternal"
 )
 
@@ -230,7 +231,7 @@ func (e *encoder) encodeDecls(decls []ast.Decl, endPos token.Pos) error {
 			continue
 
 		case *ast.Field:
-			if x.Token == token.ISA {
+			if internal.IsDefinition(x.Label) {
 				return errors.Newf(x.TokenPos, "json: definition not allowed")
 			}
 			if x.Optional != token.NoPos {