PHP Monad API Reference

PhpMonad

Interfaces

Monad: Monad interface.
Option: Option monad as a `Maybe monad`.
Result: Result monad as a `Either monad`.

Classes

Some
Err
Ok

Enums

None

Functions

some() : Some<string|int, T>: Return a `Option\Some` option containing `$value`.
none() : None: Return a `Option\None` option containing no values.
fromValue() : NoneValue>): Transform a value into an `Option`.
of() : NoneValue>): Execute a callable and transform the result into an `Option`.
tryOf() : NoneValue>): Execute a callable and transform the result into an `Option` as `Option\of()` does but also return `Option\None` if it an exception matching $exceptionClass was thrown.
flatten() : Option<string|int, U>: Converts from `Option<Option<T>>` to `Option<T>`.
ok_or() : Result<T, E>: Convert an Option to a Result.
traverse() : Result<U|null, E>: Apply a function that returns Result if Some, or ok(null) if None.
transpose() : Result<Option<string|int, U>, E>: Transposes an `Option` of a `Result` into a `Result` of an `Option`.
map() : callable(Option<string|int, T>): Option<string|int, U>: Pipeline function: Maps the Some value using the callback.
andThen() : callable(Option<string|int, T>): Option<string|int, U>: Pipeline function: Chains an Option-returning operation on Some value.
orElse() : callable(Option<string|int, mixed>): Option<string|int, mixed|U>: Pipeline function: Handles None by calling an Option-returning function.
filter() : callable(Option<string|int, mixed>): Option<string|int, mixed>: Pipeline function: Filters Some value by predicate, returning None if false.
inspect() : callable(Option<string|int, mixed>): Option<string|int, mixed>: Pipeline function: Performs a side-effect on Some value, passing through the Option.
unwrapOr() : callable(Option<string|int, mixed>): mixed: Pipeline function: Unwraps the Some value or returns the default.
unwrapOrElse() : callable(Option<string|int, mixed>): mixed: Pipeline function: Unwraps the Some value or computes a default.
expect() : callable(Option<string|int, mixed>): mixed: Pipeline function: Unwraps the Some value or throws RuntimeException with the message.
okOr() : callable(Option<string|int, mixed>): Result<mixed, E>: Pipeline function: Converts Option to Result with a fixed error value.
okOrElse() : callable(Option<string|int, mixed>): Result<mixed, E>: Pipeline function: Converts Option to Result with a lazy error value.
ok() : Ok<string|int, U>: Return a `Result\Ok` Result containing `$value`.
err() : Err<string|int, F>: Return a `Result\Err` result.
fromThrowable() : Result<T, E>: Creates a Result from a Closure that may throw an exception.
flatten() : Result<T, E>: Converts from `Result<Result<T, E>, E>` to `Result<T, E>`.
transpose() : Option<string|int, Result<U, F>>: Transposes a `Result` of an `Option` into an `Option` of a `Result`.
map_all() : Result<mixed, E>: Applies a callback to the values of multiple `Result`s if all are `Ok`.
flat_map_all() : Result<mixed, E>: Applies a `Result`-returning callback to the values of multiple `Result`s if all are `Ok`.
combine() : Result<bool, array<int, E>>
map() : callable(Result<T, mixed>): Result<U, mixed>: Pipeline function: Maps the Ok value using the callback.
mapErr() : callable(Result<mixed, E>): Result<mixed, F>: Pipeline function: Maps the Err value using the callback.
andThen() : callable(Result<T, mixed>): Result<U, mixed>: Pipeline function: Chains a Result-returning operation on Ok value.
orElse() : callable(Result<mixed, E>): Result<mixed, F>: Pipeline function: Handles Err by calling a Result-returning function.
inspect() : callable(Result<T, mixed>): Result<T, mixed>: Pipeline function: Performs a side-effect on Ok value, passing through the Result.
inspectErr() : callable(Result<mixed, E>): Result<mixed, E>: Pipeline function: Performs a side-effect on Err value, passing through the Result.
unwrapOr() : callable(Result<mixed, mixed>): mixed: Pipeline function: Unwraps the Ok value or returns the default.
unwrapOrElse() : callable(Result<mixed, E>): mixed: Pipeline function: Unwraps the Ok value or computes a default from the Err.
expect() : callable(Result<mixed, mixed>): mixed: Pipeline function: Unwraps the Ok value or throws RuntimeException with the message.

some()

Return a `Option\Some` option containing `$value`.


    
                    some(T $value) : Some<string|int, T>

Parameters

$value : T

Return values

Some<string|int, T>

none()

Return a `Option\None` option containing no values.


    
                    none() : None

Return values

None

fromValue()

Transform a value into an `Option`.


    
                    fromValue(U $value[, NoneValue|null $noneValue = null ]) : NoneValue>)

It will be a Some option containing $value if $value is different from $noneValue (default null)

Parameters

$value : U
$noneValue : NoneValue|null = null

Return values

NoneValue>)

of()

Execute a callable and transform the result into an `Option`.


    
                    of(callable(): U $callback[, NoneValue|null $noneValue = null ]) : NoneValue>)

It will be a Some option containing the result if it is different from $noneValue (default null).

Parameters

$callback : callable(): U
$noneValue : NoneValue|null = null

Return values

NoneValue>)

tryOf()

Execute a callable and transform the result into an `Option` as `Option\of()` does but also return `Option\None` if it an exception matching $exceptionClass was thrown.


    
                    tryOf(callable(): U $callback[, NoneValue|null $noneValue = null ][, E> $exceptionClass = Exception::class ]) : NoneValue>)

Parameters

$callback : callable(): U
$noneValue : NoneValue|null = null
$exceptionClass : E> = Exception::class

Return values

NoneValue>)

flatten()

Converts from `Option<Option<T>>` to `Option<T>`.


    
                    flatten(Option<string|int, Option<string|int, U>> $option) : Option<string|int, U>

Parameters

$option : Option<string|int, Option<string|int, U>>

Return values

Option<string|int, U>

ok_or()

Convert an Option to a Result.


    
                    ok_or(Option<string|int, T> $option, E $error) : Result<T, E>

Some($value) becomes ok($value). None becomes err($error).

Parameters

$option : Option<string|int, T>
$error : E

Return values

Result<T, E>

traverse()

Apply a function that returns Result if Some, or ok(null) if None.


    
                    traverse(Option<string|int, T> $option, callable(T): Result<U, E> $fn) : Result<U|null, E>

Parameters

$option : Option<string|int, T>
$fn : callable(T): Result<U, E>

Return values

Result<U|null, E>

transpose()

Transposes an `Option` of a `Result` into a `Result` of an `Option`.


    
                    transpose(Option<string|int, Result<U, E>> $option) : Result<Option<string|int, U>, E>

None will be mapped to Ok(None). Some(Ok(_)) and Some(Err(_)) will be mapped to Ok(Some(_)) and Err(_).

Parameters

$option : Option<string|int, Result<U, E>>

Return values

Result<Option<string|int, U>, E>

map()

Pipeline function: Maps the Some value using the callback.


    
                    map(callable(T): U $callback) : callable(Option<string|int, T>): Option<string|int, U>

Usage with PHP 8.5 pipeline operator: $option |> Option\map(fn($x) => $x * 2)

Parameters

$callback : callable(T): U

Return values

callable(Option<string|int, T>): Option<string|int, U>

andThen()

Pipeline function: Chains an Option-returning operation on Some value.


    
                    andThen(callable(T): Option<string|int, U> $callback) : callable(Option<string|int, T>): Option<string|int, U>

Usage with PHP 8.5 pipeline operator: $option |> Option\andThen(fn($x) => findUser($x))

Parameters

$callback : callable(T): Option<string|int, U>

Return values

callable(Option<string|int, T>): Option<string|int, U>

orElse()

Pipeline function: Handles None by calling an Option-returning function.


    
                    orElse(callable(): Option<string|int, U> $callback) : callable(Option<string|int, mixed>): Option<string|int, mixed|U>

Usage with PHP 8.5 pipeline operator: $option |> Option\orElse(fn() => getDefault())

Parameters

$callback : callable(): Option<string|int, U>

Return values

callable(Option<string|int, mixed>): Option<string|int, mixed|U>

filter()

Pipeline function: Filters Some value by predicate, returning None if false.


    
                    filter(callable(mixed): bool $predicate) : callable(Option<string|int, mixed>): Option<string|int, mixed>

Usage with PHP 8.5 pipeline operator: $option |> Option\filter(fn($x) => $x > 0)

Parameters

$predicate : callable(mixed): bool

Return values

callable(Option<string|int, mixed>): Option<string|int, mixed>

inspect()

Pipeline function: Performs a side-effect on Some value, passing through the Option.


    
                    inspect(callable(mixed): mixed $callback) : callable(Option<string|int, mixed>): Option<string|int, mixed>

Usage with PHP 8.5 pipeline operator: $option |> Option\inspect(fn($x) => logger()->info("Got: {$x}"))

Parameters

$callback : callable(mixed): mixed

Return values

callable(Option<string|int, mixed>): Option<string|int, mixed>

unwrapOr()

Pipeline function: Unwraps the Some value or returns the default.


    
                    unwrapOr(U $default) : callable(Option<string|int, mixed>): mixed

Usage with PHP 8.5 pipeline operator: $option |> Option\unwrapOr(0)

Parameters

$default : U

Return values

callable(Option<string|int, mixed>): mixed

unwrapOrElse()

Pipeline function: Unwraps the Some value or computes a default.


    
                    unwrapOrElse(callable(): mixed $callback) : callable(Option<string|int, mixed>): mixed

Usage with PHP 8.5 pipeline operator: $option |> Option\unwrapOrElse(fn() => computeDefault())

Parameters

$callback : callable(): mixed

Return values

callable(Option<string|int, mixed>): mixed

expect()

Pipeline function: Unwraps the Some value or throws RuntimeException with the message.


    
                    expect(string $message) : callable(Option<string|int, mixed>): mixed

Usage with PHP 8.5 pipeline operator: $option |> Option\expect('Value must be present')

Parameters

$message : string

Return values

callable(Option<string|int, mixed>): mixed

okOr()

Pipeline function: Converts Option to Result with a fixed error value.


    
                    okOr(E $err) : callable(Option<string|int, mixed>): Result<mixed, E>

Usage with PHP 8.5 pipeline operator: $option |> Option\okOr('not found')

Parameters

$err : E

Return values

callable(Option<string|int, mixed>): Result<mixed, E>

okOrElse()

Pipeline function: Converts Option to Result with a lazy error value.


    
                    okOrElse(callable(): E $err) : callable(Option<string|int, mixed>): Result<mixed, E>

Usage with PHP 8.5 pipeline operator: $option |> Option\okOrElse(fn() => new NotFoundException())

Parameters

$err : callable(): E

Return values

callable(Option<string|int, mixed>): Result<mixed, E>

ok()

Return a `Result\Ok` Result containing `$value`.


    
                    ok([U $value = true ]) : Ok<string|int, U>

Parameters

$value : U = true

Return values

Ok<string|int, U>

err()

Return a `Result\Err` result.


    
                    err(F $value) : Err<string|int, F>

Parameters

$value : F

Return values

Err<string|int, F>

fromThrowable()

Creates a Result from a Closure that may throw an exception.


    
                    fromThrowable(callable(): T $closure, callable(Throwable): E $errorHandler) : Result<T, E>

Parameters

$closure : callable(): T
$errorHandler : callable(Throwable): E

Return values

Result<T, E>

flatten()

Converts from `Result<Result<T, E>, E>` to `Result<T, E>`.


    
                    flatten(Result<Result<T, E>, E> $result) : Result<T, E>

Parameters

$result : Result<Result<T, E>, E>

Return values

Result<T, E>

transpose()

Transposes a `Result` of an `Option` into an `Option` of a `Result`.


    
                    transpose(Result<Option<string|int, U>, F> $result) : Option<string|int, Result<U, F>>

Ok(None) will be mapped to None. Ok(Some(_)) and Err(_) will be mapped to Some(Ok(_)) and Some(Err(_)).

Parameters

$result : Result<Option<string|int, U>, F>

Return values

Option<string|int, Result<U, F>>

map_all()

Applies a callback to the values of multiple `Result`s if all are `Ok`.


    
                    map_all(Closure $fn, Result<mixed, E> ...$results) : Result<mixed, E>

Returns the first Err encountered, or Ok wrapping the callback's return value.

Parameters

$fn : Closure
$results : Result<mixed, E>

Return values

Result<mixed, E>

flat_map_all()

Applies a `Result`-returning callback to the values of multiple `Result`s if all are `Ok`.


    
                    flat_map_all(Closure $fn, Result<mixed, E> ...$results) : Result<mixed, E>

Returns the first Err encountered, or the Result returned by the callback.

Parameters

$fn : Closure
$results : Result<mixed, E>

Return values

Result<mixed, E>

combine()


    
                    combine(Result<T, E> ...$results) : Result<bool, array<int, E>>

Parameters

$results : Result<T, E>

Return values

Result<bool, array<int, E>>

map()

Pipeline function: Maps the Ok value using the callback.


    
                    map(callable(T): U $callback) : callable(Result<T, mixed>): Result<U, mixed>

Usage with PHP 8.5 pipeline operator: $result |> Result\map(fn($x) => $x * 2)

Parameters

$callback : callable(T): U

Return values

callable(Result<T, mixed>): Result<U, mixed>

mapErr()

Pipeline function: Maps the Err value using the callback.


    
                    mapErr(callable(E): F $callback) : callable(Result<mixed, E>): Result<mixed, F>

Usage with PHP 8.5 pipeline operator: $result |> Result\mapErr(fn($e) => "Error: {$e}")

Parameters

$callback : callable(E): F

Return values

callable(Result<mixed, E>): Result<mixed, F>

andThen()

Pipeline function: Chains a Result-returning operation on Ok value.


    
                    andThen(callable(T): Result<U, F> $callback) : callable(Result<T, mixed>): Result<U, mixed>

Usage with PHP 8.5 pipeline operator: $result |> Result\andThen(fn($x) => validate($x))

Parameters

$callback : callable(T): Result<U, F>

Return values

callable(Result<T, mixed>): Result<U, mixed>

orElse()

Pipeline function: Handles Err by calling a Result-returning function.


    
                    orElse(callable(E): Result<mixed, F> $callback) : callable(Result<mixed, E>): Result<mixed, F>

Usage with PHP 8.5 pipeline operator: $result |> Result\orElse(fn($e) => recover($e))

Parameters

$callback : callable(E): Result<mixed, F>

Return values

callable(Result<mixed, E>): Result<mixed, F>

inspect()

Pipeline function: Performs a side-effect on Ok value, passing through the Result.


    
                    inspect(callable(T): mixed $callback) : callable(Result<T, mixed>): Result<T, mixed>

Usage with PHP 8.5 pipeline operator: $result |> Result\inspect(fn($x) => logger()->info("Got: {$x}"))

Parameters

$callback : callable(T): mixed

Return values

callable(Result<T, mixed>): Result<T, mixed>

inspectErr()

Pipeline function: Performs a side-effect on Err value, passing through the Result.


    
                    inspectErr(callable(E): mixed $callback) : callable(Result<mixed, E>): Result<mixed, E>

Usage with PHP 8.5 pipeline operator: $result |> Result\inspectErr(fn($e) => logger()->error($e))

Parameters

$callback : callable(E): mixed

Return values

callable(Result<mixed, E>): Result<mixed, E>

unwrapOr()

Pipeline function: Unwraps the Ok value or returns the default.


    
                    unwrapOr(U $default) : callable(Result<mixed, mixed>): mixed

Usage with PHP 8.5 pipeline operator: $result |> Result\unwrapOr(0)

Parameters

$default : U

Return values

callable(Result<mixed, mixed>): mixed

unwrapOrElse()

Pipeline function: Unwraps the Ok value or computes a default from the Err.


    
                    unwrapOrElse(callable(E): U $callback) : callable(Result<mixed, E>): mixed

Usage with PHP 8.5 pipeline operator: $result |> Result\unwrapOrElse(fn($e) => fallback($e))

Parameters

$callback : callable(E): U

Return values

callable(Result<mixed, E>): mixed

expect()

Pipeline function: Unwraps the Ok value or throws RuntimeException with the message.


    
                    expect(string $message) : callable(Result<mixed, mixed>): mixed

Usage with PHP 8.5 pipeline operator: $result |> Result\expect('Value must be present')

Parameters

$message : string

Return values

callable(Result<mixed, mixed>): mixed

PhpMonad

Table of Contents

Interfaces

Classes

Enums

Functions

Functions

some()

Parameters

Tags

Return values

none()

Return values

fromValue()

Parameters

Tags

Return values

of()

Parameters

Tags

Return values

tryOf()

Parameters

Tags

Return values

flatten()

Parameters

Tags

Return values

ok_or()

Parameters

Tags

Return values

traverse()

Parameters

Tags

Return values

transpose()

Parameters

Tags

Return values

map()

Parameters

Tags

Return values

andThen()

Parameters

Tags

Return values

orElse()

Parameters

Tags

Return values

filter()

Parameters

Return values

inspect()

Parameters

Return values

unwrapOr()

Parameters

Tags

Return values

unwrapOrElse()

Parameters

Return values

expect()

Parameters

Return values

okOr()

Parameters

Tags

Return values

okOrElse()

Parameters

Tags

Return values

ok()

Parameters

Tags