arguments.kt

src/jvmMain/kotlin/afield/app/server/arguments.kt · 53 lines

package afield.app.server

import afield.data.table.div
import afield.data.table.get
import afield.data.table.minus
import afield.data.table.plus
import afield.data.table.rem
import afield.data.table.times
import afield.runtime.execution.plus
import afield.runtime.lifecycle.plus
import afield.runtime.lifecycle.rem
import afield.ui.notation.with

import afield.audio.synth.*
import afield.graphics.vulkan.*
import afield.media.stream.*
import afield.media.video.*
import afield.app.server.Server
import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly

Command-line option parsing for the server: option reads a typed --name value pair and flag tests for a bare --name.

inline fun <reified T> option(name: String, def: () -> T): T {

The value following --name on the command line, converted to T by convertTo, or def() when the flag is absent. Throws when the flag is the last argument.

inline fun <reified T> option(name: String, def: () -> T): T {
    val i = Server.args.indexOfFirst { it.equals("--" + name, true) }
    if (i == -1) {
        return def()
    }
    if (i == Server.args.size - 1) throw IllegalArgumentException("expected argument after $name")
    return convertTo(T::class.java, Server.args[i + 1])
}

fun flag(name: String): Boolean = Server.args.any { it.equals("--$name", true) }

True when --name was given on the command line, with or without a value.

option cannot express this: it demands a following argument and throws when the flag is last.

fun <T> convertTo(target: Class<T>, value: String): T

@Suppress("UNCHECKED_CAST")
fun <T> convertTo(target: Class<T>, value: String): T {
    if (target == String::class.java) return value as T
    if (target == Int::class.java || target == Int::class.javaObjectType) return value.toInt() as T
    if (target == Double::class.java || target == Double::class.javaObjectType) return value.toDouble() as T
    if (target == Float::class.java || target == Float::class.javaObjectType) return value.toFloat() as T
    throw IllegalArgumentException("can't convert String to $target")
}