I want to pass a compiled regex to golang function, e.g.
package main
import "fmt"
import "regexp"
func foo(r *Regexp) {
fmt.Println(r)
}
func main() {
r, _ := regexp.Compile("p([a-z]+)ch")
foo(r)
}
But it is showing "undefined: Regexp"
Any hints?
Use a qualified identifier. For example,
package main
import "fmt"
import "regexp"
func foo(r *regexp.Regexp) {
fmt.Println(r)
}
func main() {
r, _ := regexp.Compile("p([a-z]+)ch")
foo(r)
}
Output:
p([a-z]+)ch
A qualified identifier is an identifier qualified with a package name prefix. Both the package name and the identifier must not be blank.
QualifiedIdent = PackageName "." identifier .A qualified identifier accesses an identifier in a different package, which must be imported. The identifier must be exported and declared in the package block of that package.
math.Sin // denotes the Sin function in package math
You can also use a dot import:
package main
import (
"fmt"
. "regexp"
)
func foo(r *Regexp) {
fmt.Println(r)
}
func main() {
r := MustCompile("p([a-z]+)ch")
foo(r)
}
However, typically it will be better to use use the fully qualified name.
regexp.Regexp