1 /* 2 Parenthesized type switch expressions originally 3 accepted by gofmt must continue to be rewritten 4 into the correct unparenthesized form. 5 6 Only type-switches that didn't declare a variable 7 in the type switch type assertion and which 8 contained only "expression-like" (named) types in their 9 cases were permitted to have their type assertion parenthesized 10 by go/parser (due to a weak predicate in the parser). All others 11 were rejected always, either with a syntax error in the 12 type switch header or in the case. 13 14 See also issue 4470. 15 */ 16 package p 17 18 func f() { 19 var x interface{} 20 switch x.(type) { // should remain the same 21 } 22 switch x.(type) { // should become: switch x.(type) { 23 } 24 25 switch x.(type) { // should remain the same 26 case int: 27 } 28 switch x.(type) { // should become: switch x.(type) { 29 case int: 30 } 31 32 switch x.(type) { // should remain the same 33 case []int: 34 } 35 36 // Parenthesized (x.(type)) in type switches containing cases 37 // with unnamed (literal) types were never permitted by gofmt; 38 // thus there won't be any code in the wild using this style if 39 // the code was gofmt-ed. 40 /* 41 switch (x.(type)) { 42 case []int: 43 } 44 */ 45 46 switch t := x.(type) { // should remain the same 47 default: 48 _ = t 49 } 50 51 // Parenthesized (x.(type)) in type switches declaring a variable 52 // were never permitted by gofmt; thus there won't be any code in 53 // the wild using this style if the code was gofmt-ed. 54 /* 55 switch t := (x.(type)) { 56 default: 57 _ = t 58 } 59 */ 60 } 61
