Pretty Print Kotlin Data Class

PrettyPrint.kt

fun Any.prettyPrint(): String {

    var indentLevel = 0
    val indentWidth = 4

    fun padding() = "".padStart(indentLevel * indentWidth)

    val toString = toString()

    val stringBuilder = StringBuilder(toString.length)

    var i = 0
    while (i < toString.length) {
        when (val char = toString[i]) {
            '(', '[', '{' -> {
                indentLevel++
                stringBuilder.appendLine(char).append(padding())
            }
            ')', ']', '}' -> {
                indentLevel--
                stringBuilder.appendLine().append(padding()).append(char)
            }
            ',' -> {
                stringBuilder.appendLine(char).append(padding())
                // ignore space after comma as we have added a newline
                val nextChar = toString.getOrElse(i + 1) { char }
                if (nextChar == ' ') i++
            }
            else -> {
                stringBuilder.append(char)
            }
        }
        i++
    }

    return stringBuilder.toString()
}

@thought-police-000 definitely love the buildString builder, i didn't know about that!

regarding the ): you could count the " as well in a "stringLevel" to decide whether one is still inside a string or to decrement the indentation level? adds complexity obviously :/

@thought-police-000 I cleaned it up more, replaced "=" by " = " and ruined it again by packing the code :)

fun Any.toPrettyDebugString(indentWidth : Int = 4) = buildString {
    fun StringBuilder.indent(level : Int) = append("".padStart(level * indentWidth))
    var ignoreSpace = false
    var indentLevel = 0
    [email protected]().onEach {
        when (it) {
            '(', '[', '{' -> appendLine(it).indent(++indentLevel)
            ')', ']', '}' -> appendLine().indent(--indentLevel).append(it)
            ','           -> appendLine(it).indent(indentLevel).also { ignoreSpace = true }
            ' '           -> if (ignoreSpace) ignoreSpace = false else append(it)
            '='           -> append(" = ")
            else          -> append(it)
        }
    }
}

công đức vô lượng