Replace regular expression matches with values of a slice-CodePudding

My goal is to replace matches of a regular expression in a string. My code:

func ReplaceBase64ToDecodedImage(data string) string {
imageSrc := make(chan []string)
go base64toPng(content, imageSrc)
result := <-imageSrc

fmt.Println("received string: ", result)
re := regexp.MustCompile(`data:image/png;base64,[^] ["']([^"'] )["']`)

s := re.ReplaceAllString(data, "slice replacement values")

return s
}

I'm streaming slice of strings via channel to replacement function. In Javascript this can be done easily using shift() function:

const paragraph = 'This ??? is ??? and ???. Have you seen the ????';
const regex = /(\?\?\?)/g;
const replacements = ['cat', 'cool', 'happy', 'dog'];
const found = paragraph.replace(regex, () => replacements.shift());

console.log(found);

but I haven't found analog for this in go and ReplaceAllString() doesn't accept slices of strings. Is there a way to achieve this in golang? I'm very new to golang, so don't know much about it's capabilities yet.

CodePudding user response：

You can do this via the ReplaceAllStringFunc method. Using this we can create a method that will iterate through the slice and return each value:


import (
    "fmt"
    "regexp"
)

func main() {
    paragraph := "This ??? is ??? and ???. Have you seen the ????"
    re := regexp.MustCompile(`(\?\?\?)`)
    replacements := []string{"cat", "cool", "happy", "dog"}
    count := 0
    replace := func(string) string {
        count  
        return replacements[count-1]
    }
    s := re.ReplaceAllStringFunc(paragraph, replace)
    fmt.Println(s)
}

CodePudding user response：

You can use ReplaceAllStringFunc function available on *regexp.Regexp. To achieve the similar functionality you did in JavaScript like this:

input := "This ??? is ??? and ???. Have you seen the ????"
replacements := []string{"cat", "cl", "happyjaxvin", "dog"}
r, _ := regexp.Compile(`\?\?\?`)

res := r.ReplaceAllStringFunc(input, func(_ string) string {
    var repl string
    repl, replacements = replacements[0], replacements[1:]
    return repl
})

fmt.Println(res)