Micro stat collector for a DevfestToulouse survey

main.kt

import java.io.File

typealias Talk = String

typealias Counter<T> = Map<T, Int>

operator fun <T> Counter<T>.plus(value: T): Counter<T> {
    val current = this.getOrDefault(value, 0)
    return this + (value to (current + 1))
}

operator fun <T> Counter<T>.plus(values: List<T>): Counter<T> =
    values.fold(this) { acc, value -> acc + value }

fun <T> Counter<T>.display(): String =
    this.toList()
        .sortedByDescending { it.second }
        .joinToString(separator = "\n") { (talk, count) -> "[$count] $talk" }


data class LineInfo(val count: Int = 0,
                    val talks: Counter<Talk> = emptyMap(),
                    val quickies: Counter<Talk> = emptyMap(),
                    val meal: Counter<String> = emptyMap()) {
    operator fun plus(line: List<String>): LineInfo =
        LineInfo(
            count = count + 1,
            talks = talks + line[1].split("/, "),
            quickies = quickies + line[2].split("/, "),
            meal = meal + line[3].split("/, ")
        )

    override fun toString(): String = """
        |----
        |Count: $count
        |-----
        |Meal:
        |${meal.display().prependIndent("\t")}
        |-----
        |Talks:
        |${talks.display().prependIndent("\t")}
        |-----
        |Quickies:
        |${quickies.display().prependIndent("\t")}
        |""".trimMargin("|")

}

const val defaultFileName = "./Devfest Toulouse 2018 - Sessions - V2 (Responses) - Form responses 1.tsv"

fun main(args: Array<String>): Unit =
    File(args.firstOrNull() ?: defaultFileName)
        .readLines()
        .drop(1)
        .map { it.split('\t') }
        .fold(LineInfo()) { acc, line -> acc + line }
        .run { println(this) }