arktype•6d ago

How to ensure comma delimited set of numbers or fallback to undefined?

I'm trying to parse in some query string parameters, like "2,3,5" that I want parsed to [2, 3, 5]. I want to fail if any any number doesn't parse to an integer. When it fails I want to return undefined. Note that this will be part of a larger type:

{
  param1: "",
  param2: "2,3,5",
}

{
  param1: "",
  param2: "2,3,5",
}

If param2 fails and fallback to undefined, I want the whole object to still parse and return { param1: "", param2: undefined }

12 Replies

TizzySaurus•6d ago

You can implement custom logic like this with a pipe (morph): https://arktype.io/docs/intro/morphs-and-more

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TizzySaurus•6d ago

const stringNumberArray = type("string.numeric.parse[]")

const foo = type({
    param1: "string",
    param2: ["string", "=>", (data) => {
        const split = data.split(","));
    
        const asNumbers = stringNumberArray(split);
        return (asNumbers instanceof type.errors) ? undefined : asNumbers;
    }]
})

const stringNumberArray = type("string.numeric.parse[]")

const foo = type({
    param1: "string",
    param2: ["string", "=>", (data) => {
        const split = data.split(","));
    
        const asNumbers = stringNumberArray(split);
        return (asNumbers instanceof type.errors) ? undefined : asNumbers;
    }]
})

or w/e

ssalbdivad•6d ago

Yeah this is almost exactly what I wrote:

import { type } from "arktype"

const parseToIntegers = type("string.integer.parse[]")

const T = type({
    param1: "string",
    param2: type.string.pipe(s => {
        const substrings = s.split(",")
        const parsed = parseToIntegers(substrings)
        if (parsed instanceof type.errors) return undefined
        return parsed
    })
})

import { type } from "arktype"

const parseToIntegers = type("string.integer.parse[]")

const T = type({
    param1: "string",
    param2: type.string.pipe(s => {
        const substrings = s.split(",")
        const parsed = parseToIntegers(substrings)
        if (parsed instanceof type.errors) return undefined
        return parsed
    })
})

Only meaningful difference is string.integer.parse if you need them to be integers

rosteroOP•6d ago

very nice. thank you both Haven't tried ark before this. I'm sure I could figure this out, but

const out = Thing({
    param1: "TypeScript",
    param2: 3
})

const out = Thing({
    param1: "TypeScript",
    param2: 3
})

Causes the whole thing to fail instead of returning { param1: "TypeScript", param2: undefined }. I forgot to mention that requirement

ssalbdivad•6d ago

That should be true of the current implementation If you read about morphs and look at the way that is written, it would have to be a string otherwise it would be an error

rosteroOP•6d ago

https://arktype.io/playground?code=import%2520%257B%2520type%2520%257D%2520from%2520%2522arktype%2522%250A%250Aconst%2520Thing%2520%253D%2520type%28%257B%250A%2509name%253A%2520%2522string%2522%252C%250A%2509%2522versions%253F%2522%253A%2520%2522%28number%2520%257C%2520string%29%255B%255D%2522%250A%257D%29%250A%250Aconst%2520out%2520%253D%2520Thing%28%257B%250A%2520%2520%2520%2520name%253A%2520%2522TypeScript%2522%252C%250A%2520%2520%2520%2520versions%253A%2520%255B%25225.8.2%2522%252C%25206%252C%25207n%255D%250A%257D%29%250A

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rosteroOP•6d ago

hmm.. I may be copying and pasting wrong ahh.. hotlinking doesn't seem to be working

ssalbdivad•6d ago

Are you clicking this?

rosteroOP•6d ago

oops. nope. i was looking at the top for that https://arktype.io/playground?code=import%2520%257B%2520type%2520%257D%2520from%2520%2522arktype%2522%250A%250Aconst%2520parseToIntegers%2520%253D%2520type%28%2522string.integer.parse%255B%255D%2522%29%250A%250Aconst%2520Thing%2520%253D%2520type%28%257B%250A%2520%2520%2520%2520param1%253A%2520%2522string%2522%252C%250A%2520%2520%2520%2520param2%253A%2520type.string.pipe%28s%2520%253D%253E%2520%257B%250A%2520%2520%2520%2520%2520%2520%2520%2520const%2520substrings%2520%253D%2520s.split%28%2522%252C%2522%29%250A%2520%2520%2520%2520%2520%2520%2520%2520const%2520parsed%2520%253D%2520parseToIntegers%28substrings%29%250A%2520%2520%2520%2520%2520%2520%2520%2520if%2520%28parsed%2520instanceof%2520type.errors%29%2520return%2520undefined%250A%2520%2520%2520%2520%2520%2520%2520%2520return%2520parsed%250A%2520%2520%2520%2520%257D%29%250A%257D%29%250A%250Aconst%2520out%2520%253D%2520Thing%28%257B%250A%2520%2520%2520%2520param1%253A%2520%2522TypeScript%2522%252C%250A%2520%2520%2520%2520param2%253A%25203%250A%257D%29%250A

ssalbdivad•6d ago

Oh I see you're saying that shouldn't fail Then you should just pipe from unknown instead and return undefined in that case

rosteroOP•6d ago

yeah, looking for a fallback to default. could be undefined or another string ok. i'll have to check out the docs later. too late in the day for me to figure this out. thanks again

ssalbdivad•6d ago

This is what I mean: https://arktype.io/playground?code=import%2520%257B%2520type%2520%257D%2520from%2520%2522arktype%2522%250A%250Aconst%2520parseToIntegers%2520%253D%2520type%28%2522string.integer.parse%255B%255D%2522%29%250A%250Aconst%2520Thing%2520%253D%2520type%28%257B%250A%2520%2520%2520%2520param1%253A%2520%2522string%2522%252C%250A%2520%2520%2520%2520param2%253A%2520type.unknown.pipe%28v%2520%253D%253E%2520%257B%250A%2520%2520%2520%2520%2520%2520%2520%2520if%28typeof%2520v%2520%21%253D%253D%2520%2522string%2522%29%2520return%2520undefined%250A%2520%2520%2520%2520%2520%2520%2520%2520const%2520substrings%2520%253D%2520v.split%28%2522%252C%2522%29%250A%2520%2520%2520%2520%2520%2520%2520%2520const%2520parsed%2520%253D%2520parseToIntegers%28substrings%29%250A%2520%2520%2520%2520%2520%2520%2520%2520if%2520%28parsed%2520instanceof%2520type.errors%29%2520return%2520undefined%250A%2520%2520%2520%2520%2520%2520%2520%2520return%2520parsed%250A%2520%2520%2520%2520%257D%29%250A%257D%29%250A%250Aconst%2520out%2520%253D%2520Thing%28%257B%250A%2520%2520%2520%2520param1%253A%2520%2522TypeScript%2522%252C%250A%2520%2520%2520%2520param2%253A%25203%250A%257D%29%250A

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How to ensure comma delimited set of numbers or fallback to undefined?

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