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// Copyright 2013 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.
package regexp_test
import (
"fmt"
"regexp"
"strings"
)
func Example() {
// Compile the expression once, usually at init time.
// Use raw strings to avoid having to quote the backslashes.
var validID = regexp.MustCompile(`^[a-z]+\[[0-9]+\]$`)
fmt.Println(validID.MatchString("adam[23]"))
fmt.Println(validID.MatchString("eve[7]"))
fmt.Println(validID.MatchString("Job[48]"))
fmt.Println(validID.MatchString("snakey"))
// Output:
// true
// true
// false
// false
}
func ExampleMatch() {
matched, err := regexp.Match(`foo.*`, []byte(`seafood`))
fmt.Println(matched, err)
matched, err = regexp.Match(`bar.*`, []byte(`seafood`))
fmt.Println(matched, err)
matched, err = regexp.Match(`a(b`, []byte(`seafood`))
fmt.Println(matched, err)
// Output:
// true <nil>
// false <nil>
// false error parsing regexp: missing closing ): `a(b`
}
func ExampleMatchString() {
matched, err := regexp.MatchString(`foo.*`, "seafood")
fmt.Println(matched, err)
matched, err = regexp.MatchString(`bar.*`, "seafood")
fmt.Println(matched, err)
matched, err = regexp.MatchString(`a(b`, "seafood")
fmt.Println(matched, err)
// Output:
// true <nil>
// false <nil>
// false error parsing regexp: missing closing ): `a(b`
}
func ExampleQuoteMeta() {
fmt.Println(regexp.QuoteMeta(`Escaping symbols like: .+*?()|[]{}^$`))
// Output:
// Escaping symbols like: \.\+\*\?\(\)\|\[\]\{\}\^\$
}
func ExampleRegexp_Find() {
re := regexp.MustCompile(`foo.?`)
fmt.Printf("%q\n", re.Find([]byte(`seafood fool`)))
// Output:
// "food"
}
func ExampleRegexp_FindAll() {
re := regexp.MustCompile(`foo.?`)
fmt.Printf("%q\n", re.FindAll([]byte(`seafood fool`), -1))
// Output:
// ["food" "fool"]
}
func ExampleRegexp_FindAllSubmatch() {
re := regexp.MustCompile(`foo(.?)`)
fmt.Printf("%q\n", re.FindAllSubmatch([]byte(`seafood fool`), -1))
// Output:
// [["food" "d"] ["fool" "l"]]
}
func ExampleRegexp_FindSubmatch() {
re := regexp.MustCompile(`foo(.?)`)
fmt.Printf("%q\n", re.FindSubmatch([]byte(`seafood fool`)))
// Output:
// ["food" "d"]
}
func ExampleRegexp_Match() {
re := regexp.MustCompile(`foo.?`)
fmt.Println(re.Match([]byte(`seafood fool`)))
fmt.Println(re.Match([]byte(`something else`)))
// Output:
// true
// false
}
func ExampleRegexp_FindString() {
re := regexp.MustCompile(`foo.?`)
fmt.Printf("%q\n", re.FindString("seafood fool"))
fmt.Printf("%q\n", re.FindString("meat"))
// Output:
// "food"
// ""
}
func ExampleRegexp_FindStringIndex() {
re := regexp.MustCompile(`ab?`)
fmt.Println(re.FindStringIndex("tablett"))
fmt.Println(re.FindStringIndex("foo") == nil)
// Output:
// [1 3]
// true
}
func ExampleRegexp_FindStringSubmatch() {
re := regexp.MustCompile(`a(x*)b(y|z)c`)
fmt.Printf("%q\n", re.FindStringSubmatch("-axxxbyc-"))
fmt.Printf("%q\n", re.FindStringSubmatch("-abzc-"))
// Output:
// ["axxxbyc" "xxx" "y"]
// ["abzc" "" "z"]
}
func ExampleRegexp_FindAllString() {
re := regexp.MustCompile(`a.`)
fmt.Println(re.FindAllString("paranormal", -1))
fmt.Println(re.FindAllString("paranormal", 2))
fmt.Println(re.FindAllString("graal", -1))
fmt.Println(re.FindAllString("none", -1))
// Output:
// [ar an al]
// [ar an]
// [aa]
// []
}
func ExampleRegexp_FindAllStringSubmatch() {
re := regexp.MustCompile(`a(x*)b`)
fmt.Printf("%q\n", re.FindAllStringSubmatch("-ab-", -1))
fmt.Printf("%q\n", re.FindAllStringSubmatch("-axxb-", -1))
fmt.Printf("%q\n", re.FindAllStringSubmatch("-ab-axb-", -1))
fmt.Printf("%q\n", re.FindAllStringSubmatch("-axxb-ab-", -1))
// Output:
// [["ab" ""]]
// [["axxb" "xx"]]
// [["ab" ""] ["axb" "x"]]
// [["axxb" "xx"] ["ab" ""]]
}
func ExampleRegexp_FindAllStringSubmatchIndex() {
re := regexp.MustCompile(`a(x*)b`)
// Indices:
// 01234567 012345678
// -ab-axb- -axxb-ab-
fmt.Println(re.FindAllStringSubmatchIndex("-ab-", -1))
fmt.Println(re.FindAllStringSubmatchIndex("-axxb-", -1))
fmt.Println(re.FindAllStringSubmatchIndex("-ab-axb-", -1))
fmt.Println(re.FindAllStringSubmatchIndex("-axxb-ab-", -1))
fmt.Println(re.FindAllStringSubmatchIndex("-foo-", -1))
// Output:
// [[1 3 2 2]]
// [[1 5 2 4]]
// [[1 3 2 2] [4 7 5 6]]
// [[1 5 2 4] [6 8 7 7]]
// []
}
func ExampleRegexp_FindSubmatchIndex() {
re := regexp.MustCompile(`a(x*)b`)
// Indices:
// 01234567 012345678
// -ab-axb- -axxb-ab-
fmt.Println(re.FindSubmatchIndex([]byte("-ab-")))
fmt.Println(re.FindSubmatchIndex([]byte("-axxb-")))
fmt.Println(re.FindSubmatchIndex([]byte("-ab-axb-")))
fmt.Println(re.FindSubmatchIndex([]byte("-axxb-ab-")))
fmt.Println(re.FindSubmatchIndex([]byte("-foo-")))
// Output:
// [1 3 2 2]
// [1 5 2 4]
// [1 3 2 2]
// [1 5 2 4]
// []
}
func ExampleRegexp_Longest() {
re := regexp.MustCompile(`a(|b)`)
fmt.Println(re.FindString("ab"))
re.Longest()
fmt.Println(re.FindString("ab"))
// Output:
// a
// ab
}
func ExampleRegexp_MatchString() {
re := regexp.MustCompile(`(gopher){2}`)
fmt.Println(re.MatchString("gopher"))
fmt.Println(re.MatchString("gophergopher"))
fmt.Println(re.MatchString("gophergophergopher"))
// Output:
// false
// true
// true
}
func ExampleRegexp_NumSubexp() {
re0 := regexp.MustCompile(`a.`)
fmt.Printf("%d\n", re0.NumSubexp())
re := regexp.MustCompile(`(.*)((a)b)(.*)a`)
fmt.Println(re.NumSubexp())
// Output:
// 0
// 4
}
func ExampleRegexp_ReplaceAll() {
re := regexp.MustCompile(`a(x*)b`)
fmt.Printf("%s\n", re.ReplaceAll([]byte("-ab-axxb-"), []byte("T")))
fmt.Printf("%s\n", re.ReplaceAll([]byte("-ab-axxb-"), []byte("$1")))
fmt.Printf("%s\n", re.ReplaceAll([]byte("-ab-axxb-"), []byte("$1W")))
fmt.Printf("%s\n", re.ReplaceAll([]byte("-ab-axxb-"), []byte("${1}W")))
// Output:
// -T-T-
// --xx-
// ---
// -W-xxW-
}
func ExampleRegexp_ReplaceAllLiteralString() {
re := regexp.MustCompile(`a(x*)b`)
fmt.Println(re.ReplaceAllLiteralString("-ab-axxb-", "T"))
fmt.Println(re.ReplaceAllLiteralString("-ab-axxb-", "$1"))
fmt.Println(re.ReplaceAllLiteralString("-ab-axxb-", "${1}"))
// Output:
// -T-T-
// -$1-$1-
// -${1}-${1}-
}
func ExampleRegexp_ReplaceAllString() {
re := regexp.MustCompile(`a(x*)b`)
fmt.Println(re.ReplaceAllString("-ab-axxb-", "T"))
fmt.Println(re.ReplaceAllString("-ab-axxb-", "$1"))
fmt.Println(re.ReplaceAllString("-ab-axxb-", "$1W"))
fmt.Println(re.ReplaceAllString("-ab-axxb-", "${1}W"))
// Output:
// -T-T-
// --xx-
// ---
// -W-xxW-
}
func ExampleRegexp_ReplaceAllStringFunc() {
re := regexp.MustCompile(`[^aeiou]`)
fmt.Println(re.ReplaceAllStringFunc("seafood fool", strings.ToUpper))
// Output:
// SeaFooD FooL
}
func ExampleRegexp_SubexpNames() {
re := regexp.MustCompile(`(?P<first>[a-zA-Z]+) (?P<last>[a-zA-Z]+)`)
fmt.Println(re.MatchString("Alan Turing"))
fmt.Printf("%q\n", re.SubexpNames())
reversed := fmt.Sprintf("${%s} ${%s}", re.SubexpNames()[2], re.SubexpNames()[1])
fmt.Println(reversed)
fmt.Println(re.ReplaceAllString("Alan Turing", reversed))
// Output:
// true
// ["" "first" "last"]
// ${last} ${first}
// Turing Alan
}
func ExampleRegexp_SubexpIndex() {
re := regexp.MustCompile(`(?P<first>[a-zA-Z]+) (?P<last>[a-zA-Z]+)`)
fmt.Println(re.MatchString("Alan Turing"))
matches := re.FindStringSubmatch("Alan Turing")
lastIndex := re.SubexpIndex("last")
fmt.Printf("last => %d\n", lastIndex)
fmt.Println(matches[lastIndex])
// Output:
// true
// last => 2
// Turing
}
func ExampleRegexp_Split() {
a := regexp.MustCompile(`a`)
fmt.Println(a.Split("banana", -1))
fmt.Println(a.Split("banana", 0))
fmt.Println(a.Split("banana", 1))
fmt.Println(a.Split("banana", 2))
zp := regexp.MustCompile(`z+`)
fmt.Println(zp.Split("pizza", -1))
fmt.Println(zp.Split("pizza", 0))
fmt.Println(zp.Split("pizza", 1))
fmt.Println(zp.Split("pizza", 2))
// Output:
// [b n n ]
// []
// [banana]
// [b nana]
// [pi a]
// []
// [pizza]
// [pi a]
}
func ExampleRegexp_Expand() {
content := []byte(`
# comment line
option1: value1
option2: value2
# another comment line
option3: value3
`)
// Regex pattern captures "key: value" pair from the content.
pattern := regexp.MustCompile(`(?m)(?P<key>\w+):\s+(?P<value>\w+)$`)
// Template to convert "key: value" to "key=value" by
// referencing the values captured by the regex pattern.
template := []byte("$key=$value\n")
result := []byte{}
// For each match of the regex in the content.
for _, submatches := range pattern.FindAllSubmatchIndex(content, -1) {
// Apply the captured submatches to the template and append the output
// to the result.
result = pattern.Expand(result, template, content, submatches)
}
fmt.Println(string(result))
// Output:
// option1=value1
// option2=value2
// option3=value3
}
func ExampleRegexp_ExpandString() {
content := `
# comment line
option1: value1
option2: value2
# another comment line
option3: value3
`
// Regex pattern captures "key: value" pair from the content.
pattern := regexp.MustCompile(`(?m)(?P<key>\w+):\s+(?P<value>\w+)$`)
// Template to convert "key: value" to "key=value" by
// referencing the values captured by the regex pattern.
template := "$key=$value\n"
result := []byte{}
// For each match of the regex in the content.
for _, submatches := range pattern.FindAllStringSubmatchIndex(content, -1) {
// Apply the captured submatches to the template and append the output
// to the result.
result = pattern.ExpandString(result, template, content, submatches)
}
fmt.Println(string(result))
// Output:
// option1=value1
// option2=value2
// option3=value3
}
func ExampleRegexp_FindIndex() {
content := []byte(`
# comment line
option1: value1
option2: value2
`)
// Regex pattern captures "key: value" pair from the content.
pattern := regexp.MustCompile(`(?m)(?P<key>\w+):\s+(?P<value>\w+)$`)
loc := pattern.FindIndex(content)
fmt.Println(loc)
fmt.Println(string(content[loc[0]:loc[1]]))
// Output:
// [18 33]
// option1: value1
}
func ExampleRegexp_FindAllSubmatchIndex() {
content := []byte(`
# comment line
option1: value1
option2: value2
`)
// Regex pattern captures "key: value" pair from the content.
pattern := regexp.MustCompile(`(?m)(?P<key>\w+):\s+(?P<value>\w+)$`)
allIndexes := pattern.FindAllSubmatchIndex(content, -1)
for _, loc := range allIndexes {
fmt.Println(loc)
fmt.Println(string(content[loc[0]:loc[1]]))
fmt.Println(string(content[loc[2]:loc[3]]))
fmt.Println(string(content[loc[4]:loc[5]]))
}
// Output:
// [18 33 18 25 27 33]
// option1: value1
// option1
// value1
// [35 50 35 42 44 50]
// option2: value2
// option2
// value2
}
func ExampleRegexp_FindAllIndex() {
content := []byte("London")
re := regexp.MustCompile(`o.`)
fmt.Println(re.FindAllIndex(content, 1))
fmt.Println(re.FindAllIndex(content, -1))
// Output:
// [[1 3]]
// [[1 3] [4 6]]
}