Other Functions

Other Useful Functions

requireTrue

Returns the specified error if the async-wrapped value is false.

'a -> Async<bool> -> Async<Result<unit, 'a>>`

requireFalse

Returns the specified error if the async-wrapped value is true.

'a -> Async<bool> -> Async<Result<unit, 'a>>`

requireSome

Converts an async-wrapped Option to a Result, using the given error if None.

'a -> Async<'b option> -> Async<Result<'b, 'a>>`

requireSomeWith

Converts an async-wrapped Option to a Result, using the given error factory if None. The error factory is only called when the value is None.

(unit -> 'a) -> Async<'b option> -> Async<Result<'b, 'a>>

requireNone

Converts an async-wrapped Option to a Result, using the given error if Some.

'a -> Async<'b option> -> Async<Result<unit, 'a>>`

requireNoneWith

Converts an async-wrapped Option to a Result, using the given error factory if Some. The error factory is only called when the value is Some.

(unit -> 'a) -> Async<'b option> -> Async<Result<unit, 'a>>

requireValueSome

Converts an async-wrapped ValueOption to a Result, using the given error if ValueNone.

'a -> Async<'b voption> -> Async<Result<'b, 'a>>

requireValueNone

Converts an async-wrapped ValueOption to a Result, using the given error if ValueSome.

'a -> Async<'b voption> -> Async<Result<unit, 'a>>

requireEqual

Returns Ok if the async-wrapped value and the provided value are equal, or the specified error if not. Same as requireEqualTo, but with a parameter order that fits normal function application better than piping.

'a -> Async<'a> -> 'b -> Async<Result<unit, 'b>>

requireEqualTo

Returns Ok if the async-wrapped value and the provided value are equal, or the specified error if not. Same as requireEqual, but with a parameter order that fits piping better than normal function application.

'a -> 'b -> Async<'a> -> Async<Result<unit, 'b>>

requireEmpty

Returns Ok if the async-wrapped sequence is empty, or the specified error if not.

'a -> Async<'b> -> Async<Result<unit, 'a>>

requireNotEmpty

Returns Ok if the async-wrapped sequence is non-empty, or the specified error if not.

'a -> Async<'b> -> Async<Result<unit, 'a>>

requireHead

Returns the first item of the sequence if it exists, or the specified error if the sequence is empty

'a -> Async<'b> -> Async<Result<'c, 'a>>

require

Returns the provided async-wrapped result if it is Ok and the predicate is true, or if the async-wrapped result is Error. If the predicate is false, returns a new async-wrapped Error result with the error value.

('a -> bool) -> 'b -> Async<Result<'a,'b>> -> Async<Result<'a,'b>>

setError

Replaces an error value of an async-wrapped result with a custom error value

'a -> Async<Result<'b, 'c>> -> Async<Result<'b, 'a>>

withError

Replaces a unit error value of an async-wrapped result with a custom error value. Safer than setError since you're not losing any information.

'a -> Async<Result<'b, unit> -> Async<Result<'b, 'a>>

defaultValue

Extracts the contained value of an async-wrapped result if Ok, otherwise uses the provided value.

'a -> Async<Result<'a, 'b>> -> Async<'a>

defaultWith

Extracts the contained value of an async-wrapped result if Ok, otherwise evaluates the given function and uses the result.

(unit -> 'a) -> Async<Result<'a, 'b>> -> Async<'a>

ignoreError

Same as defaultValue for a result where the Ok value is unit. The name describes better what is actually happening in this case.

Async<Result<unit, 'a>> -> Async<unit>

tee

If the async-wrapped result is Ok, executes the function on the Ok value. Passes through the input value unchanged.

('a -> unit) -> Async<Result<'a, 'b>> -> Async<Result<'a, 'b>>

teeError

If the async-wrapped result is Error, executes the function on the Error value. Passes through the input value unchanged.

('a -> unit) -> Async<Result<'b, 'a>> -> Async<Result<'b, 'a>>

teeIf

If the async-wrapped result is Ok and the predicate returns true for the wrapped value, executes the function on the Ok value. Passes through the input value unchanged.

('a -> bool) -> ('a -> unit) -> Async<Result<'a, 'b>> -> Async<Result<'a, 'b>>

teeErrorIf

If the async-wrapped result is Error and the predicate returns true for the wrapped value, executes the function on the Error value. Passes through the input value unchanged.

('a -> bool) -> ('a -> unit) -> Async<Result<'b, 'a>> -> Async<Result<'b, 'a>>

defaultError

Extracts the contained error value of an async-wrapped result if Error, otherwise uses the provided value.

'error -> Async<Result<'ok, 'error>> -> Async<'error>

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bindRequire Functions

The bindRequire* functions combine a bind and a require check in one step. They bind the inner Ok value through a function, then assert a condition on the result, returning Error with the given error value if the condition is not met.

bindRequireSome

Binds the async result and requires the inner Ok value to be Some, returning Error with the given error if it is None.

'error -> Async<Result<'ok option, 'error>> -> Async<Result<'ok, 'error>>

bindRequireNone

Binds the async result and requires the inner Ok value to be None, returning Error with the given error if it is Some.

'error -> Async<Result<'ok option, 'error>> -> Async<Result<unit, 'error>>

bindRequireValueSome

Binds the async result and requires the inner Ok value to be ValueSome, returning Error with the given error if it is ValueNone.

'error -> Async<Result<'ok voption, 'error>> -> Async<Result<'ok, 'error>>

bindRequireValueNone

Binds the async result and requires the inner Ok value to be ValueNone, returning Error with the given error if it is ValueSome.

'error -> Async<Result<'ok voption, 'error>> -> Async<Result<unit, 'error>>

bindRequireTrue

Binds the async result and requires the inner Ok value to be true, returning Error with the given error if it is false.

'error -> Async<Result<bool, 'error>> -> Async<Result<unit, 'error>>

bindRequireFalse

Binds the async result and requires the inner Ok value to be false, returning Error with the given error if it is true.

'error -> Async<Result<bool, 'error>> -> Async<Result<unit, 'error>>

bindRequireNotNull

Binds the async result and requires the inner Ok value to be non-null, returning Error with the given error if it is null.

'error -> Async<Result<'ok, 'error>> -> Async<Result<'ok, 'error>>

bindRequireEqual

Binds the async result and requires the inner Ok value to equal the provided value, returning Error with the given error if they differ.

'ok -> 'error -> Async<Result<'ok, 'error>> -> Async<Result<unit, 'error>>

bindRequireEmpty

Binds the async result and requires the inner Ok sequence to be empty, returning Error with the given error if it is not.

'error -> Async<Result<#seq<'ok>, 'error>> -> Async<Result<unit, 'error>>

bindRequireNotEmpty

Binds the async result and requires the inner Ok sequence to be non-empty, returning Error with the given error if it is empty.

'error -> Async<Result<#seq<'ok>, 'error>> -> Async<Result<unit, 'error>>

bindRequireHead

Binds the async result and returns the first element of the inner Ok sequence, returning Error with the given error if the sequence is empty.

'error -> Async<Result<#seq<'ok>, 'error>> -> Async<Result<'ok, 'error>>