1 // Copyright 2012 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 main 6 7 import ( 8 "io/ioutil" 9 "regexp" 10 ) 11 12 func AppendByte(slice []byte, data ...byte) []byte { 13 m := len(slice) 14 n := m + len(data) 15 if n > cap(slice) { // if necessary, reallocate 16 // allocate double what's needed, for future growth. 17 newSlice := make([]byte, (n+1)*2) 18 copy(newSlice, slice) 19 slice = newSlice 20 } 21 slice = slice[0:n] 22 copy(slice[m:n], data) 23 return slice 24 } 25 26 // STOP OMIT 27 28 // Filter returns a new slice holding only 29 // the elements of s that satisfy fn. 30 func Filter(s []int, fn func(int) bool) []int { 31 var p []int // == nil 32 for _, i := range s { 33 if fn(i) { 34 p = append(p, i) 35 } 36 } 37 return p 38 } 39 40 // STOP OMIT 41 42 var digitRegexp = regexp.MustCompile("[0-9]+") 43 44 func FindDigits(filename string) []byte { 45 b, _ := ioutil.ReadFile(filename) 46 return digitRegexp.Find(b) 47 } 48 49 // STOP OMIT 50 51 func CopyDigits(filename string) []byte { 52 b, _ := ioutil.ReadFile(filename) 53 b = digitRegexp.Find(b) 54 c := make([]byte, len(b)) 55 copy(c, b) 56 return c 57 } 58 59 // STOP OMIT 60 61 func main() { 62 // place holder; no need to run 63 } 64
