gleam/int

Functions for working with integers.

Division by zero

In Erlang division by zero results in a crash, however Gleam does not have partial functions and operators in core so instead division by zero returns zero, a behaviour taken from Pony, Coq, and Lean.

This may seem unexpected at first, but it is no less mathematically valid than crashing or returning a special value. Division by zero is undefined in mathematics.

Types

InvalidBase

</>

Error value when trying to operate with a base out of the allowed range.

pub type InvalidBase {
  InvalidBase
}

Constructors

```
InvalidBase
```

Functions

absolute_value

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pub fn absolute_value(x: Int) -> Int

Returns the absolute value of the input.

Examples

> absolute_value(-12)
12

> absolute_value(10)
10

add

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pub fn add(a: Int, b: Int) -> Int

Adds two integers together.

It’s the function equivalent of the + operator. This function is useful in higher order functions or pipes.

Examples

> add(1, 2)
3

import gleam/list
> list.fold([1, 2, 3], 0, add)
6

> 3 |> add(2)
5

base_parse

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pub fn base_parse(string: String, base: Int) -> Result(Int, Nil)

Parses a given string as an int in a given base if possible. Supports only bases 2 to 36, for values outside of which this function returns an Error(Nil).

Examples

> base_parse("10", 2)
Ok(2)

> base_parse("30", 16)
Ok(48)

> base_parse("1C", 36)
Ok(48)

> base_parse("48", 1)
Error(Nil)

> base_parse("48", 37)
Error(Nil)

bitwise_and

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pub fn bitwise_and(x: Int, y: Int) -> Int

Calculates the bitwise AND of its arguments.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

bitwise_exclusive_or

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pub fn bitwise_exclusive_or(x: Int, y: Int) -> Int

Calculates the bitwise XOR of its arguments.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

bitwise_not

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pub fn bitwise_not(x: Int) -> Int

Calculates the bitwise NOT of its argument.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

bitwise_or

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pub fn bitwise_or(x: Int, y: Int) -> Int

Calculates the bitwise OR of its arguments.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

bitwise_shift_left

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pub fn bitwise_shift_left(x: Int, y: Int) -> Int

Calculates the result of an arithmetic left bitshift.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

bitwise_shift_right

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pub fn bitwise_shift_right(x: Int, y: Int) -> Int

Calculates the result of an arithmetic right bitshift.

The exact behaviour of this function depends on the target platform. On Erlang it is equivalent to bitwise operations on ints, on JavaScript it is equivalent to bitwise operations on big-ints.

clamp

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pub fn clamp(
  x: Int,
  min min_bound: Int,
  max max_bound: Int,
) -> Int

Restricts an int between a lower and upper bound.

Examples

> clamp(40, min: 50, max: 60)
50

compare

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pub fn compare(a: Int, with b: Int) -> Order

Compares two ints, returning an order.

Examples

> compare(2, 3)
Lt

> compare(4, 3)
Gt

> compare(3, 3)
Eq

digits

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pub fn digits(
  x: Int,
  base: Int,
) -> Result(List(Int), InvalidBase)

Splits an integer into its digit representation in the specified base

Examples

> digits(234, 10)
Ok([2,3,4])

> digits(234, 1)
Error(InvalidBase)

divide

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pub fn divide(dividend: Int, by divisor: Int) -> Result(Int, Nil)

Performs a truncated integer division.

Returns division of the inputs as a Result: If the given divisor equals 0, this function returns an Error.

Examples

> divide(0, 1)
Ok(1)

> divide(1, 0)
Error(Nil)

> divide(5, 2)
Ok(2)

> divide(-99, 2)
Ok(-49)

floor_divide

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pub fn floor_divide(
  dividend: Int,
  by divisor: Int,
) -> Result(Int, Nil)

Performs a floored integer division, which means that the result will always be rounded towards negative infinity.

If you want to perform truncated integer division (rounding towards zero), use int.divide() or the / operator instead.

Returns division of the inputs as a Result: If the given divisor equals 0, this function returns an Error.

Examples

> floor_divide(1, 0)
Error(Nil)

> floor_divide(5, 2)
Ok(2)

> floor_divide(6, -4)
Ok(-2)

> floor_divide(-99, 2)
Ok(-50)

is_even

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pub fn is_even(x: Int) -> Bool

Returns whether the value provided is even.

Examples

> is_even(2)
True

> is_even(3)
False

is_odd

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pub fn is_odd(x: Int) -> Bool

Returns whether the value provided is odd.

Examples

> is_odd(3)
True

> is_odd(2)
False

max

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pub fn max(a: Int, b: Int) -> Int

Compares two ints, returning the larger of the two.

Examples

> max(2, 3)
3

min

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pub fn min(a: Int, b: Int) -> Int

Compares two ints, returning the smaller of the two.

Examples

> min(2, 3)
2

modulo

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pub fn modulo(dividend: Int, by divisor: Int) -> Result(Int, Nil)

Computes the modulo of an integer division of inputs as a Result.

Returns division of the inputs as a Result: If the given divisor equals 0, this function returns an Error.

Most the time you will want to use the % operator instead of this function.

Examples

> modulo(3, 2)
Ok(1)

> modulo(1, 0)
Error(Nil)

> modulo(10, -1)
Ok(0)

> modulo(13, by: 3)
Ok(1)

> modulo(-13, by: 3)
Ok(2)

> modulo(13, by: -3)
Ok(-2)

> modulo(-13, by: -3)
Ok(-1)

multiply

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pub fn multiply(a: Int, b: Int) -> Int

Multiplies two integers together.

It’s the function equivalent of the * operator. This function is useful in higher order functions or pipes.

Examples

> multiply(2, 4)
8

import gleam/list
> list.fold([2, 3, 4], 1, multiply)
24

> 3 |> multiply(2)
6

negate

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pub fn negate(x: Int) -> Int

Returns the negative of the value provided.

Examples

> negate(1)
-1

parse

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pub fn parse(string: String) -> Result(Int, Nil)

Parses a given string as an int if possible.

Examples

> parse("2")
Ok(2)

> parse("ABC")
Error(Nil)

power

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pub fn power(base: Int, of exponent: Float) -> Result(Float, Nil)

Returns the results of the base being raised to the power of the exponent, as a Float.

Examples

> power(2, -1.0)
Ok(0.5)

> power(2, 2.0)
Ok(4.0)

> power(8, 1.5)
Ok(22.627416997969522)

> 4 |> power(of: 2.0)
Ok(16.0)

> power(-1, 0.5)
Error(Nil)

product

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pub fn product(numbers: List(Int)) -> Int

Multiplies a list of ints and returns the product.

Example

> product([2, 3, 4])
24

random

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pub fn random(min: Int, max: Int) -> Int

Generates a random int between the given minimum and maximum values.

Examples

> random(1, 5)
2

remainder

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pub fn remainder(
  dividend: Int,
  by divisor: Int,
) -> Result(Int, Nil)

Computes the remainder of an integer division of inputs as a Result.

Returns division of the inputs as a Result: If the given divisor equals 0, this function returns an Error.

Most the time you will want to use the % operator instead of this function.

Examples

> remainder(3, 2)
Ok(1)

> remainder(1, 0)
Error(Nil)

> remainder(10, -1)
Ok(0)

> remainder(13, by: 3)
Ok(1)

> remainder(-13, by: 3)
Ok(-1)

> remainder(13, by: -3)
Ok(1)

> remainder(-13, by: -3)
Ok(-1)

square_root

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pub fn square_root(x: Int) -> Result(Float, Nil)

Returns the square root of the input as a Float.

Examples

> square_root(4)
Ok(2.0)

> square_root(-16)
Error(Nil)

subtract

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pub fn subtract(a: Int, b: Int) -> Int

Subtracts one int from another.

It’s the function equivalent of the - operator. This function is useful in higher order functions or pipes.

Examples

> subtract(3, 1)
2.0

import gleam/list
> list.fold([1, 2, 3], 10, subtract)
4

> 3 |> subtract(2)
1

> 3 |> subtract(2, _)
-1

sum

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pub fn sum(numbers: List(Int)) -> Int

Sums a list of ints.

Example

> sum([1, 2, 3])
6

to_base16

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pub fn to_base16(x: Int) -> String

Prints a given int to a string using base-16.

Examples

> to_base16(48)
"30"

to_base2

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pub fn to_base2(x: Int) -> String

Prints a given int to a string using base-2.

Examples

> to_base2(2)
"10"

to_base36

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pub fn to_base36(x: Int) -> String

Prints a given int to a string using base-36.

Examples

> to_base36(48)
"1C"

to_base8

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pub fn to_base8(x: Int) -> String

Prints a given int to a string using base-8.

Examples

> to_base8(15)
"17"

to_base_string

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pub fn to_base_string(
  x: Int,
  base: Int,
) -> Result(String, InvalidBase)

Prints a given int to a string using the base number provided. Supports only bases 2 to 36, for values outside of which this function returns an Error(InvalidBase). For common bases (2, 8, 16, 36), use the to_baseN functions.

Examples

> to_base_string(2, 2)
Ok("10")

> to_base_string(48, 16)
Ok("30")

> to_base_string(48, 36)
Ok("1C")

> to_base_string(48, 1)
Error(InvalidBase)

> to_base_string(48, 37)
Error(InvalidBase)

to_float

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pub fn to_float(x: Int) -> Float

Takes an int and returns its value as a float.

Examples

> to_float(5)
5.0

> to_float(0)
0.0

> to_float(-3)
-3.0

to_string

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pub fn to_string(x: Int) -> String

Prints a given int to a string.

Examples

> to_string(2)
"2"

undigits

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pub fn undigits(
  numbers: List(Int),
  base: Int,
) -> Result(Int, InvalidBase)

Joins a list of digits into a single value. Returns an error if the base is less than 2 or if the list contains a digit greater than or equal to the specified base.

Examples

> undigits([2,3,4], 10)
Ok(234)

> undigits([2,3,4], 1)
Error(InvalidBase)

> undigits([2,3,4], 2)
Error(InvalidBase)

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