Created
March 10, 2020 16:22
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64id - an id encoding for more readable urls, but still keeping a long number
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function EncodeDigit(digit) { | |
if (digit < 10) | |
return digit + 48 | |
else if (digit < 36) | |
return digit + 97 - 10 | |
else if (digit < 62) | |
return digit + 65 - 36 | |
else if (digit == 62) | |
return "_" | |
else if (digit == 63) | |
return "$" | |
} | |
function EncodeNumber(number) { | |
let digit = EncodeDigit(number % 64); | |
// console.log(`char[${number % 64}] = ${digit} => ${String.fromCodePoint(digit)}`) | |
let x = (number >= 64 ? EncodeNumber(Math.floor(number / 64)) : "") + String.fromCodePoint(digit); | |
return x; | |
} | |
function DecodeDigit(char) { | |
let digit = char.charCodeAt(0); | |
if (digit == 95) | |
return 62 | |
if (digit == 36) | |
return 63 | |
if (digit >= 97) | |
return digit - 87 | |
if (digit >= 65) | |
return digit - 29 | |
if (digit >= 48) | |
return digit - 48 | |
} | |
function DecodeNumber(number) { | |
return [...number].reduceRight((acc, x, i) => { | |
let digit = DecodeDigit(x) | |
let index = Math.pow(64, number.length - i - 1) | |
let value = index * digit | |
// console.log(`[${x}] = ${digit} * 64^${index} = ${value} | acc: ${acc}`) | |
return acc + value | |
}, 0) | |
} | |
let encoded = EncodeNumber(123454321) | |
console.log(encoded); | |
console.log(DecodeNumber(encoded)); |
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