Golang : Removes punctuation or defined delimiter from the user's input

Problem :

You need to clean up your user's input from punctuation or certain delimiter defined by you. For example, you need to parse the user's input, but only want to deal with words and certain symbols for tokenizing purpose. How to do that?

Solution :

First, we will write a function to test if the single character is a punctuation or defined delimiter.

 package main

 import (
 "fmt"
 "strings"
 )

 const delim = "?!.;,*"

 func isDelim(c string) bool {
 if strings.Contains(delim, c) {
 return true
 }
 return false
 }

 func main() {

 char := "i"

 fmt.Printf("Is [%v] a delim : %v\n", char, isDelim(char))

 char = ","

 fmt.Printf("Is [%v] a delim : %v\n", char, isDelim(char))

 char = ";"

 fmt.Printf("Is [%v] a delim : %v\n", char, isDelim(char))

 char = "s"

 fmt.Printf("Is [%v] a delim : %v\n", char, isDelim(char))

 }

Output :

Is [i] a delim : false

Is [,] a delim : true

Is [;] a delim : true

Is [s] a delim : false

Then, iterate each of the characters in a string to test out if the character is a punctuation or delimiter defined by you.

 package main

 import (
 "fmt"
 "strings"
 )

 const delim = "?!.;,*"

 func isDelim(c string) bool {
 if strings.Contains(delim, c) {
 return true
 }
 return false
 }

 func cleanString(input string) string {

 size := len(input)
 temp := ""
 var prevChar string

 for i := 0; i < size; i++ {
 //fmt.Println(input[i])
 str := string(input[i]) // convert to string for easier operation
 if (str == " " && prevChar != " ") || !isDelim(str) {
 temp += str
 prevChar = str
 } else if prevChar != " " && isDelim(str) {
 temp += " "
 }
 }
 return temp
 }

 func main() {

 str := "H ello! Who are you?!, What are you?"

 newStr := cleanString(str)

 fmt.Println("Original : ", str)

 fmt.Println("Cleaned : ", newStr)

 }

Output :

Original : H ello! Who are you?!, What are you?

Cleaned : H ello Who are you What are you

Reference :

https://en.wikipedia.org/wiki/Delimiter