go提供对正则表达式的内置支持。 下面是go中常见的regexp相关任务的一些例子。

具体的每个函数，可参考示例中的代码 -

所有的示例代码，都放在 f:\worksp\golang 目录下。安装go编程环境请参考：http://www.h3.com/go/go_environment.html

string-formatting.go的完整代码如下所示 -

package main

import "bytes"
import "fmt"
import "regexp"

func main() {

    // this tests whether a pattern matches a string.
    match, _ := regexp.matchstring("p([a-z]+)ch", "peach")
    fmt.println(match)

    // above we used a string pattern directly, but for
    // other regexp tasks you'll need to `compile` an
    // optimized `regexp` struct.
    r, _ := regexp.compile("p([a-z]+)ch")

    // many methods are available on these structs. here's
    // a match test like we saw earlier.
    fmt.println(r.matchstring("peach"))

    // this finds the match for the regexp.
    fmt.println(r.findstring("peach punch"))

    // this also finds the first match but returns the
    // start and end indexes for the match instead of the
    // matching text.
    fmt.println(r.findstringindex("peach punch"))

    // the `submatch` variants include information about
    // both the whole-pattern matches and the submatches
    // within those matches. for example this will return
    // information for both `p([a-z]+)ch` and `([a-z]+)`.
    fmt.println(r.findstringsubmatch("peach punch"))

    // similarly this will return information about the
    // indexes of matches and submatches.
    fmt.println(r.findstringsubmatchindex("peach punch"))

    // the `all` variants of these functions apply to all
    // matches in the input, not just the first. for
    // example to find all matches for a regexp.
    fmt.println(r.findallstring("peach punch pinch", -1))

    // these `all` variants are available for the other
    // functions we saw above as well.
    fmt.println(r.findallstringsubmatchindex(
        "peach punch pinch", -1))

    // providing a non-negative integer as the second
    // argument to these functions will limit the number
    // of matches.
    fmt.println(r.findallstring("peach punch pinch", 2))

    // our examples above had string arguments and used
    // names like `matchstring`. we can also provide
    // `[]byte` arguments and drop `string` from the
    // function name.
    fmt.println(r.match([]byte("peach")))

    // when creating constants with regular expressions
    // you can use the `mustcompile` variation of
    // `compile`. a plain `compile` won't work for
    // constants because it has 2 return values.
    r = regexp.mustcompile("p([a-z]+)ch")
    fmt.println(r)

    // the `regexp` package can also be used to replace
    // subsets of strings with other values.
    fmt.println(r.replaceallstring("a peach", "<fruit>"))

    // the `func` variant allows you to transform matched
    // text with a given function.
    in := []byte("a peach")
    out := r.replaceallfunc(in, bytes.toupper)
    fmt.println(string(out))
}

执行上面代码，将得到以下输出结果 -

f:\worksp\golang>go run regular-expressions.go
true
true
peach
[0 5]
[peach ea]
[0 5 1 3]
[peach punch pinch]
[[0 5 1 3] [6 11 7 9] [12 17 13 15]]
[peach punch]
true
p([a-z]+)ch
a <fruit>
a peach