From: Robert Griesemer <gri@golang.org>
Date: Thu, 27 Oct 2016 18:20:20 +0000 (-0700)
Subject: cmd/compile, go/parser: disallow "type T = p.T" - must use "=>"
X-Git-Tag: go1.8beta1~548
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=89632aa1832a02e36acd458b3b35257d8133ae0c;p=gostls13.git

cmd/compile, go/parser: disallow "type T = p.T" - must use "=>"

I had added this originally so we can play with different notations
but it doesn't make sense to keep it around since gofmt will convert
a type alias declaration using "=" into one using "=>" anyhow. More
importantly, the spec doesn't permit it.

Change-Id: Icb010b5a9976aebf877e48b3ce9d7245559ca494
Reviewed-on: https://go-review.googlesource.com/32105
Run-TryBot: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
---

diff --git a/src/cmd/compile/internal/gc/bexport.go b/src/cmd/compile/internal/gc/bexport.go
index ea0f6d7aaf..933fd72fa0 100644
--- a/src/cmd/compile/internal/gc/bexport.go
+++ b/src/cmd/compile/internal/gc/bexport.go
@@ -11,7 +11,7 @@
 The export data is a serialized description of the graph of exported
 "objects": constants, types, variables, and functions. Aliases may be
 directly reexported, and unaliased types may be indirectly reexported
-(as part of the type of a directly exorted object). More generally,
+(as part of the type of a directly exported object). More generally,
 objects referred to from inlined function bodies can be reexported.
 We need to know which package declares these reexported objects, and
 therefore packages are also part of the export graph.
diff --git a/src/cmd/compile/internal/syntax/parser.go b/src/cmd/compile/internal/syntax/parser.go
index d0dec3ab1b..fcf4f5b692 100644
--- a/src/cmd/compile/internal/syntax/parser.go
+++ b/src/cmd/compile/internal/syntax/parser.go
@@ -365,8 +365,7 @@ func (p *parser) typeDecl(group *Group) Decl {
 	}
 
 	name := p.name()
-	// permit both: type T => p.T and: type T = p.T for now
-	if p.got(_Rarrow) || p.got(_Assign) {
+	if p.got(_Rarrow) {
 		return p.aliasDecl(Type, name, group)
 	}
 
diff --git a/src/go/parser/parser.go b/src/go/parser/parser.go
index 0cff9f005e..375ae03e86 100644
--- a/src/go/parser/parser.go
+++ b/src/go/parser/parser.go
@@ -2343,8 +2343,7 @@ func (p *parser) parseTypeSpec(doc *ast.CommentGroup, _ token.Token, _ int) ast.
 	}
 
 	ident := p.parseIdent()
-	// permit both: type T => p.T and: type T = p.T for now
-	if p.tok == token.ALIAS || p.tok == token.ASSIGN {
+	if p.tok == token.ALIAS {
 		p.next()
 		return p.parseAliasSpec(doc, ast.Typ, ident)
 	}
diff --git a/src/go/parser/short_test.go b/src/go/parser/short_test.go
index 0360cea0a6..514dd4c90c 100644
--- a/src/go/parser/short_test.go
+++ b/src/go/parser/short_test.go
@@ -47,7 +47,7 @@ var valids = []string{
 	`package p; var _ = map[P]int{P{}:0, {}:1}`,
 	`package p; var _ = map[*P]int{&P{}:0, {}:1}`,
 	`package p; const c => p.C; var x => X; type T => p.T; func F => p.F`,
-	`package p; var (_ int; x => p.X; y => Y); type (t => T; t1 = p.T1)`,
+	`package p; var (_ int; x => p.X; y => Y); type (t => T; t1 => p.T1)`,
 }
 
 func TestValid(t *testing.T) {
diff --git a/src/go/printer/testdata/declarations.golden b/src/go/printer/testdata/declarations.golden
index 4d888cc8a4..ff14aba1a7 100644
--- a/src/go/printer/testdata/declarations.golden
+++ b/src/go/printer/testdata/declarations.golden
@@ -1015,8 +1015,6 @@ type c => p.C
 type (
 	s	struct{}
 	a	=> A
-	b	=> A
-	c	=> foo
 	ddd	=> p.Foo
 )
 
diff --git a/src/go/printer/testdata/declarations.input b/src/go/printer/testdata/declarations.input
index c3a76858b7..748db3b6b1 100644
--- a/src/go/printer/testdata/declarations.input
+++ b/src/go/printer/testdata/declarations.input
@@ -1029,8 +1029,6 @@ type c => p.C
 type (
 	s struct{}
 	a => A
-	b = A
-	c = foo
 	ddd => p.Foo
 )