Increment/decrement the value by one for a given base

[c0ncentus]

hi,

use case

hexadecimal - increment or decrement #FFFFFF to # 000000 vice et versa
or increment or decrement binary system (combinaisons system wich 1 is true and 0 false)

decrement or increment by 1 can be usefull. I ask it beacause easy to make if you enjoy the idea ...

[ryasmi]

Hi @c0ncentus - that's a really interesting idea. Would you propose doing that by introducing a new increment parameter to the convertBase function? I think perhaps an options object parameter that contains an increment option might be a good idea if so. Could potentially utilise that same options parameter to allow custom alphabets to be used what do you think?

[c0ncentus]

Hi ,

If you like, I code it but very functionnal way and free to you to implement what you like.

My idea is mainly to do only via string,

not base16=> base10 and then +1 and redo base 10 => base 16 because excpected to be a lot of calcul with hight numbers ...

[ryasmi]

@c0ncentus yeah please do, sounds interesting.

[c0ncentus]

console.log(incrAnyBase("4", NUMERALS_10.join(''), true))// 5
console.log(incrAnyBase("107", NUMERALS_10.join(''), true))// 108
console.log(incrAnyBase("107.205", NUMERALS_10.join(''), true))// 108.205
console.log(incrAnyBase("9", NUMERALS_10.join(''), true)) // 10

console.log(incrAnyBase("-7", NUMERALS_10.join(''), false))// decrement  -8

all these tests works but i have to deal with

// console.log(incrAnyBase("199", NUMERALS_10.join(''), true)) // 200

now it's equal to "2290" ... i will investigate later ... also would have some code to review for decrement ....

[c0ncentus]

// Support float number
// Support negatif/positif
// Support add/ remoove
// treat negative number like "-" and "30" ...


// dont support if alphabet contains "-"


function incrAnyDigitBase(digit: string, alphabet: string, isPlus: boolean = true) {
    return isPlus === true
        ? cloneDeep(alphabet[indexNext(alphabet.indexOf(digit), alphabet.length)])
        : cloneDeep(alphabet[indexPrvs(alphabet.indexOf(digit), alphabet.length)])
}

export function incrAnyNumberBase(value: string, alphabet: string, isPlus: boolean = true) {
    let incrNext: boolean = false;
    let decrNext: boolean = false;
    const numP = numSplit(value);
    let newValue = numP.intPart.split('')
    const DECIMAL_PART = `${numP.decPart === alphabet[0] ? "" : `.${numP.decPart}`}`;

    // when negative, or 0 (decrement) or -1 (increment, int part)
    if (value[0] === "-") {
        return value === `-${alphabet[1]}` && isPlus === true
            ? alphabet[0] + DECIMAL_PART
            : `-${incrAnyNumberBase(value.replace("-", ""), alphabet, !isPlus)}`
    }
    if (value === alphabet[0] && isPlus === false) { return `-${alphabet[1]}${DECIMAL_PART}` }


    let index = newValue.length - 1
    let letter: string = newValue[index];
    incrNext = letter === alphabet[alphabet.length - 1];
    decrNext = letter === alphabet[0]

    // none special operation to do ... 
    if ((incrNext === false && isPlus === true) || (decrNext === false && isPlus === false)) {
        newValue[index] = incrAnyDigitBase(letter, alphabet, isPlus)
    }
    // hardest case ...
    else {
        if (isPlus === true) {
            while (isPlus === true && index >= 0 && incrNext === true) {
                newValue[index] = incrAnyDigitBase(letter, alphabet, isPlus)
                incrNext = letter === alphabet[alphabet.length - 1];
                decrNext = letter === alphabet[1];
                if (
                    (incrNext === true
                        && index === 0
                        && isPlus === true)
                ) { newValue = arrInsertAt(newValue, alphabet[1], 0) }
                index = index - 1;
                letter = newValue[index];
            }
        }
        else {
            while (isPlus === false && index >= 0 && decrNext === true) {

                const res = cloneDeep(alphabet[indexPrvs(alphabet.indexOf(letter), alphabet.length)]);

                newValue[index] = cloneDeep(res)
                if (index === 0 && res === alphabet[0]) { newValue.splice(0, 1) }
                index = index - 1
                letter = newValue[index];
            }
        }
    }
    return `${newValue.join("")}${DECIMAL_PART}`
}

Not optimized but whatever ... you can split into 2 functions also ...
Note: clonedeep is made for copy value from array,

have external function like

export function numSplit(value: number | string): { intPart: string, decPart: string } {
    const [integerPart, decimalPart] = typeNumAmbiToStr(value).split('.')
    return {
        intPart: integerPart
            ? integerPart === "-"
                ? "-0"
                : integerPart
            : "0",
        decPart: decimalPart
            ? decimalPart
            : "0"
    }
}

export function indexPrvs(index: number, lenghtItems: number) { return numCropByInter([0, lenghtItems - 1], index - 1) }
export function indexNext(index: number, lenghtItems: number) { return numCropByInter([0, lenghtItems - 1], index + 1) }


export function numCropByInter(inter: [number, number], res: number, isForcedInclude: boolean = false) {
    if (isForcedInclude === true) { return inter[1] < res ? inter[1] : inter[0] > res ? inter[0] : res }
    const TO = Math.abs(inter[1] - inter[0]);
    const into = mod((res - inter[0]), TO + 1) + inter[0];
    return into
}

Test made

console.log(incrAnyNumberBase("-1", NUMERALS_10.join(''), true))// 0
console.log(incrAnyNumberBase("0", NUMERALS_10.join(''), false))// -1



console.log(incrAnyNumberBase("4", NUMERALS_10.join(''), true))// 5
console.log(incrAnyNumberBase("107", NUMERALS_10.join(''), true))// 108
console.log(incrAnyNumberBase("107.205", NUMERALS_10.join(''), true))// 108.205
console.log(incrAnyNumberBase("-7", NUMERALS_10.join(''), false))// -8
console.log(incrAnyNumberBase("9", NUMERALS_10.join(''), true)) // 10
console.log(incrAnyNumberBase("19", NUMERALS_10.join(''), true))// 20
console.log(incrAnyNumberBase("199.99", NUMERALS_10.join(''), true))// 200.99


console.log(incrAnyNumberBase("2.78", NUMERALS_10.join(''), false))// 1.78
console.log(incrAnyNumberBase("-3.78", NUMERALS_10.join(''), true))// -2.78
console.log(incrAnyNumberBase("33", NUMERALS_10.join(''), false))// 32
console.log(incrAnyNumberBase("30", NUMERALS_10.join(''), false))// 29
console.log(incrAnyNumberBase("10", NUMERALS_10.join(''), false))// 9
console.log(incrAnyNumberBase("10000", NUMERALS_10.join(''), false))// 9999

the last thing will be to made banchmark on small and hight numbers ...

[ryasmi]

Hi @c0ncentus - not got around to fully reviewing this yet and figuring out how to get it into the code. Will get to it soon 👍

[ryasmi]

Hi @c0ncentus this is really interesting. I guess it feels a bit limited in the sense that you can only increment of decrement by 1. Is the primary use case for this incrementing and decrementing RGB colour values?

[c0ncentus]

you got what you have, do you have others ideas ? :o
PS : Rgb is obviously not the main way to acheve this ... Use Hex color instead ....

[ryasmi]

@c0ncentus I guess I'd just do the increment after the base 10 conversion in the existing code so that you can increment by floats, etc. It's not ideal to convert from a base to base 10 and back again, particularly with large numbers like you say, but I guess that non optimal solution will highlight if anyone needs it to work for extremely large numbers before investing too much time in a solution that is restricted to incrementing by 1/-1. What do you think?

[c0ncentus]

I dont know what you expect from me, I suggest idea, I suggest a solution.

Do what you think it is the best.