Result (FSharp.Core)

Result Module

Namespace: FSharp.Core
Assembly: FSharp.Core.dll

Contains operations for working with values of type Result.

Functions and values

Function or value	Description
`bind binder result` Full Usage: `bind binder result` Parameters: binder : `'T -> Result<'U, 'TError>` - A function that takes the value of type T from a result and transforms it into a result containing a value of type U. result : `Result<'T, 'TError>` - The input result. Returns: `Result<'U, 'TError>` A result of the output type of the binder.	`bind f inp` evaluates to `match inp with Error e -> Error e \| Ok x -> f x` binder : `'T -> Result<'U, 'TError>` A function that takes the value of type T from a result and transforms it into a result containing a value of type U. result : `Result<'T, 'TError>` The input result. Returns: `Result<'U, 'TError>` A result of the output type of the binder. Example let tryParse (input: string) = match System.Int32.TryParse input with \| true, v -> Ok v \| false, _ -> Error "couldn't parse" Error "message" \|> Result.bind tryParse // evaluates to Error "message" Ok "42" \|> Result.bind tryParse // evaluates to Ok 42 Ok "Forty-two" \|> Result.bind tryParse // evaluates to Error "couldn't parse"
`map mapping result` Full Usage: `map mapping result` Parameters: mapping : `'T -> 'U` - A function to apply to the OK result value. result : `Result<'T, 'TError>` - The input result. Returns: `Result<'U, 'TError>` A result of the input value after applying the mapping function, or Error if the input is Error.	`map f inp` evaluates to `match inp with Error e -> Error e \| Ok x -> Ok (f x)`. mapping : `'T -> 'U` A function to apply to the OK result value. result : `Result<'T, 'TError>` The input result. Returns: `Result<'U, 'TError>` A result of the input value after applying the mapping function, or Error if the input is Error. Example Ok 1 \|> Result.map (fun x -> "perfect") // evaluates to Ok "perfect" Error "message" \|> Result.map (fun x -> "perfect") // evaluates to Error "message"
`mapError mapping result` Full Usage: `mapError mapping result` Parameters: mapping : `'TError -> 'U` - A function to apply to the Error result value. result : `Result<'T, 'TError>` - The input result. Returns: `Result<'T, 'U>` A result of the error value after applying the mapping function, or Ok if the input is Ok.	`map f inp` evaluates to `match inp with Error x -> Error (f x) \| Ok v -> Ok v`. mapping : `'TError -> 'U` A function to apply to the Error result value. result : `Result<'T, 'TError>` The input result. Returns: `Result<'T, 'U>` A result of the error value after applying the mapping function, or Ok if the input is Ok. Example Ok 1 \|> Result.mapError (fun x -> "bar") // evaluates to Ok 1 Error "foo" \|> Result.mapError (fun x -> "bar") // evaluates to Error "bar"