How to use dynamic string substitution in Kotlin?-CodePudding

I'm looking for a Kotlin way to do a dynamic values substitution into a string. It is clear how to implement it, just want to check if there is something similar in standard library.

Could you help me to find a function which given template and data map returns a resulting string with all template keys replaced with their values?

fun format(template: String, data: Map<String, Any>): String { /* magic */ }

format("${a} ${b} ${a}", mapOf("a" to "Home", "b" to "Sweet))   // -> "Home Sweet Home"

CodePudding user response：

fun format(template: String, data: Map<String, String>): String {
  var retval = template
  data.forEach { dataEntry ->
    retval = retval.replace("\${"   dataEntry.key   "}", dataEntry.value)
  }
  return retval
}

// The $ signs in the template string need to be escaped to prevent
// string interpolation
format("\${a} \${b} \${a}", mapOf("a" to "Home", "b" to "Sweet"))

CodePudding user response：

Not shorter than lukas.j's answer, just different (using Regex):

val regex = "\\\$\\{([a-z])}".toRegex()

fun format(template: String, data: Map<String, String>) =
    regex.findAll(template).fold(template) { result, matchResult ->
        val (match, key) = matchResult.groupValues
        result.replace(match, data[key] ?: match)
    }