src/regexp/example_test.go - go - Git at Google

 // 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`)))

 	// Output:
 	// true
 }

 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_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_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_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
 }
	// 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`)))

	// Output:
	// true
	}

	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_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_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_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
	}