Merge pull request #1285 from xushiwei/cls

parseErrWrapExpr: ErrWrapExpr as PrimaryExpr

parser/_testdata/errwrap3/errwrap3.gop

@@ -0,0 +1,2 @@
+mkdir! "foo"
+println foo()!.fields

parser/_testdata/errwrap3/parser.expect

@@ -0,0 +1,47 @@
+package main
+
+file errwrap3.gop
+noEntrypoint
+ast.FuncDecl:
+ Name:
+ ast.Ident:
+ Name: main
+ Type:
+ ast.FuncType:
+ Params:
+ ast.FieldList:
+ Body:
+ ast.BlockStmt:
+ List:
+ ast.ExprStmt:
+ X:
+ ast.CallExpr:
+ Fun:
+ ast.ErrWrapExpr:
+ X:
+ ast.Ident:
+ Name: mkdir
+ Tok: !
+ Args:
+ ast.BasicLit:
+ Kind: STRING
+ Value: "foo"
+ ast.ExprStmt:
+ X:
+ ast.CallExpr:
+ Fun:
+ ast.Ident:
+ Name: println
+ Args:
+ ast.SelectorExpr:
+ X:
+ ast.ErrWrapExpr:
+ X:
+ ast.CallExpr:
+ Fun:
+ ast.Ident:
+ Name: foo
+ Tok: !
+ Sel:
+ ast.Ident:
+ Name: fields

parser/_testdata/fncall/fncall.gop

@@ -0,0 +1 @@
+fn(1)(x)

parser/_testdata/fncall/parser.expect

@@ -0,0 +1,30 @@
+package main
+
+file fncall.gop
+noEntrypoint
+ast.FuncDecl:
+ Name:
+ ast.Ident:
+ Name: main
+ Type:
+ ast.FuncType:
+ Params:
+ ast.FieldList:
+ Body:
+ ast.BlockStmt:
+ List:
+ ast.ExprStmt:
+ X:
+ ast.CallExpr:
+ Fun:
+ ast.CallExpr:
+ Fun:
+ ast.Ident:
+ Name: fn
+ Args:
+ ast.BasicLit:
+ Kind: INT
+ Value: 1
+ Args:
+ ast.Ident:
+ Name: x

parser/parser.go

@@ -1354,7 +1354,7 @@ func (p *parser) parseFuncTypeOrLit() ast.Expr {
 
 func (p *parser) isCommand(x ast.Expr) bool {
  switch x.(type) {
- case *ast.Ident, *ast.SelectorExpr:
+ case *ast.Ident, *ast.SelectorExpr, *ast.ErrWrapExpr:
  default:
  return false
  }
@@ -1908,6 +1908,9 @@ L:
  } else {
  break L
  }
+ case token.NOT, token.QUESTION:
+ x = &ast.ErrWrapExpr{X: x, Tok: p.tok, TokPos: p.pos}
+ p.next()
  default:
  if allowCmd && p.isCommand(x) {
  if lhs {
@@ -1923,6 +1926,18 @@ L:
  return x
 }
 
+// parseErrWrapExpr: expr! expr? expr?:defval
+func (p *parser) parseErrWrapExpr(lhs, allowTuple, allowCmd bool) ast.Expr {
+ x := p.parsePrimaryExpr(lhs, allowTuple, allowCmd)
+ if expr, ok := x.(*ast.ErrWrapExpr); ok {
+ if p.tok == token.COLON {
+ p.next()
+ expr.Default = p.parseUnaryExpr(false, true, false)
+ }
+ }
+ return x
+}
+
 // If lhs is set and the result is an identifier, it is not resolved.
 func (p *parser) parseUnaryExpr(lhs, allowTuple, allowCmd bool) ast.Expr {
  if p.trace {
@@ -1993,27 +2008,6 @@ func (p *parser) parseUnaryExpr(lhs, allowTuple, allowCmd bool) ast.Expr {
  return p.parseErrWrapExpr(lhs, allowTuple, allowCmd)
 }
 
-// parseErrWrapExpr: expr! expr? expr?:defval
-func (p *parser) parseErrWrapExpr(lhs, allowTuple, allowCmd bool) ast.Expr {
- x := p.parsePrimaryExpr(lhs, allowTuple, allowCmd)
- switch p.tok {
- case token.NOT: // expr!
- expr := &ast.ErrWrapExpr{X: x, Tok: token.NOT, TokPos: p.pos}
- p.next()
- return expr
- case token.QUESTION: // expr? expr?:defval
- expr := &ast.ErrWrapExpr{X: x, Tok: token.QUESTION, TokPos: p.pos}
- p.next()
- if p.tok == token.COLON {
- p.next()
- expr.Default = p.parseUnaryExpr(false, true, false)
- }
- return expr
- default:
- return x
- }
-}
-
 func (p *parser) tokPrec() (token.Token, int) {
  tok := p.tok
  if p.inRHS && tok == token.ASSIGN {