Created
February 20, 2014 12:32
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Regular expressions are flexible, but that obviously comes with a time penalty. If you need to check for very specific cases, you may be better off writing the function yourself. Check this out...
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| package main | |
| import ( | |
| "regexp" | |
| "testing" | |
| ) | |
| func matches(str, pattern string) bool { | |
| p, s := 0, 0 | |
| matches := true | |
| for ; matches && p < len(pattern) && s < len(str); p++ { | |
| if pattern[p] == '%' { | |
| for s < len(str) && str[s] != '.' { | |
| s++ | |
| } | |
| } else { | |
| matches = (str[s] == pattern[p]) | |
| s++ | |
| } | |
| } | |
| return matches && p == len(pattern) && s == len(str) | |
| } | |
| var str = "os.disk.myfancydiskdrive.tput" | |
| var re = regexp.MustCompile("^os.disk.[^.]*.tput$") | |
| func BenchmarkMatch(b *testing.B) { | |
| for i := 0; i < b.N; i++ { | |
| if !matches(str, "os.disk.%.tput") { | |
| b.Fatal("string should match") | |
| } | |
| } | |
| } | |
| func BenchmarkRegex(b *testing.B) { | |
| for i := 0; i < b.N; i++ { | |
| if !re.MatchString(str) { | |
| b.Fatal("string should match") | |
| } | |
| } | |
| } |
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| BenchmarkMatch 20000000 76.7 ns/op | |
| BenchmarkRegex 500000 3119 ns/op |
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