specification: composite literal example invalid after gofmt #1243
Description
A parsing ambiguity arises when a composite literal using the TypeName form of the
LiteralType appears between the keyword and the opening brace of the block of an
"if", "for", or "switch" statement, because the braces
surrounding the expressions in the literal are confused with those introducing the block
of statements. To resolve the ambiguity in this rare case, the composite literal must
appear within parentheses.
if x == (T{a,b,c}[i]) { ... }
if (x == T{a,b,c}[i]) { ... }
Composite literals, The Go Programming Language Specification.
http://golang.org/doc/go_spec.html#Composite_literals
The second example is invalid because it does not survive gofmt.
package main
type T [3]int
func main() {
var a, b, c, i, x int
if (x == T{a, b, c}[i]) {
}
}
After gofmt -w,
package main
type T [3]int
func main() {
var a, b, c, i, x int
if x == T{a, b, c}[i] {
}
}
6g error:
7: syntax error: unexpected }, expecting := or = or comma
hg id 4c76cc96e113 tip