repeated conditionals returning values · beginners

Stream: beginners

Topic: repeated conditionals returning values

Brendan Hansknecht (Jan 15 2024 at 07:19):

Does anyone have a good idea of how to clean this code up. Currently I have 3 values that all depend on the same conditional:

actuallyFlap = !prev.lastFlap && flap && flapAllowed
yVel =
    if actuallyFlap then
        jumpSpeed
    else
        prev.player.yVel + gravity

nextAnim =
    if actuallyFlap then
        anim = prev.rocciFlapAnim
        { anim & index: 0, state: RunOnce }
    else
        updateAnimation prev.frameCount prev.rocciFlapAnim

flapSoundTask =
    if actuallyFlap then
        W4.tone {
            startFreq: 700,
            endFreq: 870,
            channel: Pulse1 Quarter,
            attackTime: 10,
            sustainTime: 0,
            decayTime: 3,
            releaseTime: 5,
            volume: 10,
            peakVolume: 20,
        }
    else
        Task.ok {}

full context

I originally had it all in one conditional returning a tuple, but I don't think that reads well:

(yVel, nextAnim, soundTask) =
    if !prev.lastFlap && flap && flapAllowed then
        anim = prev.rocciFlapAnim
        (
            jumpSpeed,
            { anim & index: 0, state: RunOnce },
            W4.tone {
                startFreq: 700,
                endFreq: 870,
                channel: Pulse1 Quarter,
                attackTime: 10,
                sustainTime: 0,
                decayTime: 3,
                releaseTime: 5,
                volume: 10,
                peakVolume: 20,
            },
        )
    else
        (
            prev.player.yVel + gravity,
            updateAnimation prev.frameCount prev.rocciFlapAnim,
            Task.ok {},
        )

full context

Brian Carroll (Jan 15 2024 at 07:52):

How about a record instead of a tuple? I have often done this in Elm.

{ yVel, nextAnim, soundTask } =
    if !prev.lastFlap && flap && flapAllowed then
        anim = prev.rocciFlapAnim
        {
            yVel : jumpSpeed,
            nextAnim : { anim & index: 0, state: RunOnce },
            soundTask : W4.tone {
                startFreq: 700,
                endFreq: 870,
                channel: Pulse1 Quarter,
                attackTime: 10,
                sustainTime: 0,
                decayTime: 3,
                releaseTime: 5,
                volume: 10,
                peakVolume: 20,
            },
        }
    else
        {
            yVel : prev.player.yVel + gravity,
            nextAnim : updateAnimation prev.frameCount prev.rocciFlapAnim,
            soundTask : Task.ok {},
        }

Brian Carroll (Jan 15 2024 at 07:57):

This way, you get to "label" each expression. And it doesn't count as shadowing because field names don't clash with variable names. And yet the record destructuring syntax makes them the same names. :thumbs_up:

Brendan Hansknecht (Jan 15 2024 at 16:02):

That works better than I would expect

Last updated: Jul 26 2025 at 12:14 UTC