regexp: add examples
Update #4125
R=minux.ma, rsc
CC=golang-dev
https://golang.org/cl/6847107
diff --git a/src/pkg/regexp/example_test.go b/src/pkg/regexp/example_test.go
index aa92e0b..b0ad9d3 100644
--- a/src/pkg/regexp/example_test.go
+++ b/src/pkg/regexp/example_test.go
@@ -20,3 +20,125 @@
// false
// false
}
+
+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 ExampleRegexp_FindString() {
+ re := regexp.MustCompile("fo.?")
+ fmt.Printf("%q\n", re.FindString("seafood"))
+ fmt.Printf("%q\n", re.FindString("meat"))
+ // Output:
+ // "foo"
+ // ""
+}
+
+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_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_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
+}
