| // run |
| |
| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| // Test switch statements. |
| |
| package main |
| |
| import "os" |
| |
| func assert(cond bool, msg string) { |
| if !cond { |
| print("assertion fail: ", msg, "\n") |
| panic(1) |
| } |
| } |
| |
| func main() { |
| i5 := 5 |
| i7 := 7 |
| hello := "hello" |
| |
| switch true { |
| case i5 < 5: |
| assert(false, "<") |
| case i5 == 5: |
| assert(true, "!") |
| case i5 > 5: |
| assert(false, ">") |
| } |
| |
| switch { |
| case i5 < 5: |
| assert(false, "<") |
| case i5 == 5: |
| assert(true, "!") |
| case i5 > 5: |
| assert(false, ">") |
| } |
| |
| switch x := 5; true { |
| case i5 < x: |
| assert(false, "<") |
| case i5 == x: |
| assert(true, "!") |
| case i5 > x: |
| assert(false, ">") |
| } |
| |
| switch x := 5; true { |
| case i5 < x: |
| assert(false, "<") |
| case i5 == x: |
| assert(true, "!") |
| case i5 > x: |
| assert(false, ">") |
| } |
| |
| switch i5 { |
| case 0: |
| assert(false, "0") |
| case 1: |
| assert(false, "1") |
| case 2: |
| assert(false, "2") |
| case 3: |
| assert(false, "3") |
| case 4: |
| assert(false, "4") |
| case 5: |
| assert(true, "5") |
| case 6: |
| assert(false, "6") |
| case 7: |
| assert(false, "7") |
| case 8: |
| assert(false, "8") |
| case 9: |
| assert(false, "9") |
| default: |
| assert(false, "default") |
| } |
| |
| switch i5 { |
| case 0, 1, 2, 3, 4: |
| assert(false, "4") |
| case 5: |
| assert(true, "5") |
| case 6, 7, 8, 9: |
| assert(false, "9") |
| default: |
| assert(false, "default") |
| } |
| |
| switch i5 { |
| case 0: |
| case 1: |
| case 2: |
| case 3: |
| case 4: |
| assert(false, "4") |
| case 5: |
| assert(true, "5") |
| case 6: |
| case 7: |
| case 8: |
| case 9: |
| default: |
| assert(i5 == 5, "good") |
| } |
| |
| switch i5 { |
| case 0: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 1: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 2: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 3: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 4: |
| dummy := 0 |
| _ = dummy |
| assert(false, "4") |
| case 5: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 6: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 7: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 8: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 9: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| default: |
| dummy := 0 |
| _ = dummy |
| assert(i5 == 5, "good") |
| } |
| |
| fired := false |
| switch i5 { |
| case 0: |
| dummy := 0 |
| _ = dummy |
| fallthrough // tests scoping of cases |
| case 1: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 2: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 3: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 4: |
| dummy := 0 |
| _ = dummy |
| assert(false, "4") |
| case 5: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 6: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 7: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 8: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| case 9: |
| dummy := 0 |
| _ = dummy |
| fallthrough |
| default: |
| dummy := 0 |
| _ = dummy |
| fired = !fired |
| assert(i5 == 5, "good") |
| } |
| assert(fired, "fired") |
| |
| count := 0 |
| switch i5 { |
| case 0: |
| count = count + 1 |
| fallthrough |
| case 1: |
| count = count + 1 |
| fallthrough |
| case 2: |
| count = count + 1 |
| fallthrough |
| case 3: |
| count = count + 1 |
| fallthrough |
| case 4: |
| count = count + 1 |
| assert(false, "4") |
| case 5: |
| count = count + 1 |
| fallthrough |
| case 6: |
| count = count + 1 |
| fallthrough |
| case 7: |
| count = count + 1 |
| fallthrough |
| case 8: |
| count = count + 1 |
| fallthrough |
| case 9: |
| count = count + 1 |
| fallthrough |
| default: |
| assert(i5 == count, "good") |
| } |
| assert(fired, "fired") |
| |
| switch hello { |
| case "wowie": |
| assert(false, "wowie") |
| case "hello": |
| assert(true, "hello") |
| case "jumpn": |
| assert(false, "jumpn") |
| default: |
| assert(false, "default") |
| } |
| |
| fired = false |
| switch i := i5 + 2; i { |
| case i7: |
| fired = true |
| default: |
| assert(false, "fail") |
| } |
| assert(fired, "var") |
| |
| // switch on nil-only comparison types |
| switch f := func() {}; f { |
| case nil: |
| assert(false, "f should not be nil") |
| default: |
| } |
| |
| switch m := make(map[int]int); m { |
| case nil: |
| assert(false, "m should not be nil") |
| default: |
| } |
| |
| switch a := make([]int, 1); a { |
| case nil: |
| assert(false, "m should not be nil") |
| default: |
| } |
| |
| i := 0 |
| switch x := 5; { |
| case i < x: |
| os.Exit(0) |
| case i == x: |
| case i > x: |
| os.Exit(1) |
| } |
| } |