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Module

x/rimbu/typical/strnum.ts>Subtract

Rimbu is a TypeScript library focused on immutable, performant, and type-safe collections and other tools.
rimbu-org/rimbu
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type alias Subtract
import { type Subtract } from "https://deno.land/x/rimbu@0.13.1/typical/strnum.ts";

Returns the result of subtracting the second from the first given string-number, or never if the second value is greater than the first. (Only natural numbers currently supported)

Examples

Example 1

SSubtract<'13', '8'> => '5'
SSubtract<'5371', '139'> => '5232'
SSubtract<'100', '101'> => never

Type Parameters

N1 extends string
N2 extends string
definition: N1 extends N2 ? "0" : N1 extends Str.Append<infer N1Start, Digit> ? N2 extends Str.Append<infer N2Start, Digit> ? N1 extends Str.Append<N1Start, infer N1LastDigit> ? N2 extends Str.Append<N2Start, infer N2LastDigit> ? SubDigit<Digit & N1LastDigit, Digit & N2LastDigit> extends [infer NewDigit, infer Underflow] ? Underflow extends true ? N1Start extends "" ? never : Subtract<Subtract<N1Start, N2Start>, "1"> extends infer Start ? Start extends "0" ? Digit & NewDigit : Str.Append<string & Start, Digit & NewDigit> : never : Subtract<N1Start, N2Start> extends infer Start ? Start extends "0" ? Digit & NewDigit : Str.Append<string & Start, Digit & NewDigit> : never : never : never : never : N1 : never