main/libgo/go/exp/ebnf/ebnf_test.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package ebnf
   6
   7 import (
   8         "bytes"
   9         "testing"
  10 )
  11
  12 var goodGrammars = []string{
  13         `Program = .`,
  14
  15         `Program = foo .
  16          foo = "foo" .`,
  17
  18         `Program = "a" | "b" "c" .`,
  19
  20         `Program = "a" … "z" .`,
  21
  22         `Program = Song .
  23          Song = { Note } .
  24          Note = Do | (Re | Mi | Fa | So | La) | Ti .
  25          Do = "c" .
  26          Re = "d" .
  27          Mi = "e" .
  28          Fa = "f" .
  29          So = "g" .
  30          La = "a" .
  31          Ti = ti .
  32          ti = "b" .`,
  33 }
  34
  35 var badGrammars = []string{
  36         `Program = | .`,
  37         `Program = | b .`,
  38         `Program = a … b .`,
  39         `Program = "a" … .`,
  40         `Program = … "b" .`,
  41         `Program = () .`,
  42         `Program = [] .`,
  43         `Program = {} .`,
  44 }
  45
  46 func checkGood(t *testing.T, src string) {
  47         grammar, err := Parse("", bytes.NewBuffer([]byte(src)))
  48         if err != nil {
  49                 t.Errorf("Parse(%s) failed: %v", src, err)
  50                 return
  51         }
  52         if err = Verify(grammar, "Program"); err != nil {
  53                 t.Errorf("Verify(%s) failed: %v", src, err)
  54         }
  55 }
  56
  57 func checkBad(t *testing.T, src string) {
  58         _, err := Parse("", bytes.NewBuffer([]byte(src)))
  59         if err == nil {
  60                 t.Errorf("Parse(%s) should have failed", src)
  61         }
  62 }
  63
  64 func TestGrammars(t *testing.T) {
  65         for _, src := range goodGrammars {
  66                 checkGood(t, src)
  67         }
  68         for _, src := range badGrammars {
  69                 checkBad(t, src)
  70         }
  71 }