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effect-extras

NumberX overview

Generic, framework-agnostic extensions to Effect’s Number module.

Added in v0.0.0

Table of contents

conversions

indexToExcel

Converts a 0-indexed column number into its bijective base-26 spreadsheet label (A, B, …, Z, AA, AB, …).

Returns None for a negative index; every non-negative index maps to a Some label. Indexing is 0-based here, so 0 is "A" and 25 is "Z", unlike the 1-based numbering shown in most spreadsheet references.

Signature

export declare const indexToExcel: (index: number) => Option.Option<string>

Example

import { Option } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

assert.deepStrictEqual(NumberX.indexToExcel(0), Option.some("A"))
assert.deepStrictEqual(NumberX.indexToExcel(26), Option.some("AA"))
assert.deepStrictEqual(NumberX.indexToExcel(-1), Option.none())

Added in v0.0.0

padLeftZeroes

Renders number as a string, left-padded with zeroes to at least numberDigits characters.

If the number’s string representation is already as long as (or longer than) numberDigits, it is returned unchanged.

Signature

export declare const padLeftZeroes: ((numberDigits: number) => (number: number) => string) &
  ((number: number, numberDigits: number) => string)

Example

import { pipe } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

// data-first
assert.deepStrictEqual(NumberX.padLeftZeroes(1, 3), "001")

// longer than the target width is returned unchanged
assert.deepStrictEqual(NumberX.padLeftZeroes(1000, 3), "1000")

// data-last (piped)
assert.deepStrictEqual(pipe(10, NumberX.padLeftZeroes(3)), "010")

Added in v0.0.0

toFixed

Formats number with a fixed number of decimal places, returning a string.

A pipeable wrapper around Number.prototype.toFixed — the result is rounded (not truncated) to numberDigits decimals and always carries exactly that many digits after the point.

Signature

export declare const toFixed: ((numberDigits: number) => (number: number) => string) &
  ((number: number, numberDigits: number) => string)

Example

import { pipe } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

// data-first
assert.deepStrictEqual(NumberX.toFixed(3.236242, 2), "3.24")

// data-last (piped)
assert.deepStrictEqual(pipe(3.236242, NumberX.toFixed(0)), "3")

Added in v0.0.0

mapping

indexToRank

Converts a 0-indexed value to its 1-indexed rank by adding 1.

Handy for presentation where humans count from one (e.g. the element at index 0 is shown as “item 1”).

Signature

export declare const indexToRank: (index: number) => number

Example

import { NumberX } from "@nunofyobiz/effect-extras"

assert.deepStrictEqual(NumberX.indexToRank(0), 1)
assert.deepStrictEqual(NumberX.indexToRank(4), 5)

Added in v0.0.0

roundToDigits

Rounds number to a fixed number of decimal places, returning a number.

Unlike {@link toFixed}, the result stays a number (no trailing zeroes) — it formats via toFixed then parses back, which sidesteps the usual floating-point rounding artifacts. See https://stackoverflow.com/a/29494612/22875620.

Signature

export declare const roundToDigits: ((numberDigits: number) => (number: number) => number) &
  ((number: number, numberDigits: number) => number)

Example

import { pipe } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

// data-first
assert.deepStrictEqual(NumberX.roundToDigits(3.236242, 2), 3.24)

// data-last (piped)
assert.deepStrictEqual(pipe(3.736242, NumberX.roundToDigits(0)), 4)

Added in v0.0.0

unsafe

unsafeLogBase

Computes the logarithm of number in the given base, throwing when the inputs fall outside the domain of log.

Throws when number <= 0, when base is <= 0 or 1, or when number and base sit on opposite sides of 1 (a fractional base with number >= 1, or a base >= 1 with number < 1) — cases where the real logarithm is undefined or non-finite. Reach for it only when the inputs are already known to be valid.

Signature

export declare const unsafeLogBase: ((base: number) => (number: number) => number) &
  ((number: number, base: number) => number)

Example

import { pipe } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

// data-first
assert.deepStrictEqual(NumberX.unsafeLogBase(8, 2), 3)
assert.deepStrictEqual(NumberX.unsafeLogBase(100, 10), 2)

// data-last (piped)
assert.deepStrictEqual(pipe(8, NumberX.unsafeLogBase(2)), 3)

// throws outside the domain of log
assert.throws(() => NumberX.unsafeLogBase(0, 2))

Added in v0.0.0

unsafeToPercentOf

Expresses numerator as a percentage of total, throwing on division by zero.

Returns (numerator / total) * 100. When total is 0 the percentage is undefined, so this throws rather than returning Infinity or NaN — use it only when total is known to be non-zero.

Signature

export declare const unsafeToPercentOf: ((total: number) => (numerator: number) => number) &
  ((numerator: number, total: number) => number)

Example

import { pipe } from "effect"
import { NumberX } from "@nunofyobiz/effect-extras"

// data-first
assert.deepStrictEqual(NumberX.unsafeToPercentOf(1, 2), 50)
assert.deepStrictEqual(NumberX.unsafeToPercentOf(2, 1), 200)

// data-last (piped)
assert.deepStrictEqual(pipe(1, NumberX.unsafeToPercentOf(2)), 50)

// throws on division by zero
assert.throws(() => NumberX.unsafeToPercentOf(1, 0))

Added in v0.0.0