FsToolkit.ErrorHandling
  • README
  • FsToolkit.ErrorHandling
    • Result
      • apply
      • bind
      • check
      • Computation Expression
      • either Functions
      • fold
      • ignore
      • map
      • map2
      • map3
      • mapError
      • Operators
      • orElse Functions
      • Other Functions
      • require Functions
      • tee Functions
      • tryCreate
      • zip
      • zipError
      • Lists
        • traverseResultM
        • sequenceResultM
        • traverseResultA
        • sequenceResultA
      • Sequences
        • traverseResultM
        • sequenceResultM
        • traverseResultA
        • sequenceResultA
      • Transforms
        • ofChoice
    • Option
      • bind
      • bindNull
      • Computation Expression
      • either
      • map
      • map2
      • map3
      • sequenceAsync
      • sequenceResult
      • sequenceTask
      • sequenceTaskResult
      • tee Functions
      • traverseAsync
      • traverseResult
      • traverseTask
      • traverseTaskResult
      • zip
      • Lists
        • traverseOptionM
        • sequenceOptionM
        • traverseVOptionM
        • sequenceVOptionM
      • Sequences
        • traverseOptionM
        • sequenceOptionM
        • traverseVOptionM
        • sequenceVOptionM
      • Transforms
        • ofNull
        • ofPair
        • ofResult
        • ofValueOption
        • toValueOption
    • ResultOption
      • apply
      • bind
      • Computation Expression
      • ignore
      • map
      • map2
      • map3
      • mapError
      • Operators
      • zip
      • zipError
      • Transforms
        • ofChoice
        • ofOption
        • ofResult
    • AsyncResult
      • apply
      • bind
      • check
      • Computation Expression
      • error
      • foldResult
      • ignore
      • map
      • map2
      • map3
      • mapError
      • Operators
      • Other Functions
      • zip
      • zipError
      • List
        • traverseAsyncResultM
        • sequenceAsyncResultM
        • traverseAsyncResultA
        • sequenceAsyncResultA
      • Sequences
        • traverseAsyncResultM
        • sequenceAsyncResultM
        • traverseAsyncResultA
        • sequenceAsyncResultA
      • Transforms
        • ofAsync
        • ofResult
        • ofTask
        • ofTaskAction
    • AsyncOption
      • apply
      • bind
      • Computation Expression
      • either
      • map
      • orElse Functions
      • Other Functions
    • AsyncResultOption
      • apply
      • bind
      • Computation Expression
      • ignore
      • map
      • map2
      • map3
      • Operators
      • Transforms
        • ofAsyncOption
        • ofAsyncResult
        • ofOption
        • ofResult
    • Task
      • apply
      • bind
      • bindV
      • catch
      • Computation Expression
      • ignore
      • map
      • mapV
      • map2
      • map3
      • zip
      • Transforms
        • ofUnit
    • TaskOption
      • apply
      • bind
      • Computation Expression
      • either
      • map
      • Other Functions
      • zip
    • TaskResult
      • apply
      • bind
      • check
      • catch
      • Computation Expression
      • ignore
      • map
      • map2
      • map3
      • mapError
      • Operators
      • Other Functions
      • error
      • zip
      • zipError
      • Lists
        • traverseTaskResultM
        • sequenceTaskResultM
        • traverseTaskResultA
        • sequenceTaskResultA
      • Transforms
        • ofAsync
        • ofResult
        • ofTask
    • TaskResultOption
      • apply
      • bind
      • Computation Expression
      • ignore
      • map
      • map2
      • map3
      • Operators
    • Validation
      • apply
      • Computation Expression
      • error
      • map
      • map2
      • map3
      • mapError
      • mapErrors
      • Operators
      • zip
      • Transforms
        • ofChoice
        • ofResult
    • AsyncValidation
      • apply
      • Computation Expression
      • error
      • map
      • map2
      • map3
      • mapError
      • mapErrors
      • Operators
      • zip
      • Transforms
        • ofChoice
        • ofResult
    • TaskValidation
      • apply
      • Computation Expression
      • error
      • map
      • map2
      • map3
      • mapError
      • mapErrors
      • Operators
      • zip
      • Transforms
        • ofChoice
        • ofResult
  • FsToolkit.ErrorHandling.AsyncSeq
    • AsyncSeq
      • Computation Expression
  • FsToolkit.ErrorHandling.IcedTasks
    • CancellableTaskResult
      • apply
      • bind
      • Computation Expression
      • getCancellationToken
      • map
      • Operators
      • Other Functions
      • zip
      • parallelZip
    • CancellableTaskValidation
      • apply
      • bind
      • Computation Expression
      • error
      • getCancellationToken
      • map
      • map2
      • map3
      • mapError
      • mapErrors
      • Operators
      • zip
      • parallelZip
      • Transforms
        • ofChoice
        • ofResult
  • FsToolkit.ErrorHandling.JobResult
    • Job
      • apply
      • map2
      • map3
      • singleton
      • zip
    • JobOption
      • apply
      • bind
      • ce
      • either
      • map
    • JobResult
      • apply
      • bind
      • catch
      • Computation Expression
      • error
      • fromTask
      • fromUnitTask
      • ignore
      • map
      • map2
      • map3
      • mapError
      • Operators
      • Other Functions
      • zip
      • zipError
      • Lists
        • traverseJobResultM
        • sequenceJobResultM
        • traverseJobResultA
        • sequenceJobResultA
      • Transforms
        • ofAsync
        • ofJob
        • ofResult
        • fromTask
        • fromUnitTask
    • JobResultOption
      • apply
      • bind
      • Computation Expression
      • ignore
      • map
      • map2
      • map3
  • General Docs
    • Bind Mappings
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  • Option Computation Expression
  • Examples:
  1. FsToolkit.ErrorHandling
  2. Option

Computation Expression

PreviousbindNullNexteither

Last updated 1 year ago

Option Computation Expression

Namespace: FsToolkit.ErrorHandling

Examples:

Example 1

// Option<int>
let addResult = option {
  let! x = tryParseInt "35"
  let! y = tryParseInt "5"
  let! z = tryParseInt "2"
  return add x y z
}

Example 2

Example taken from

// int -> int -> int option
let tryDivide x y =
    match y with
    | 0 -> None
    | _ -> Some (x / y)

// int -> int -> int option
let multiplyIfEven x y =
    match y % 2 with
    | 0 -> Some <| x * y
    | _ -> None
 
// int option  
let resultNone = option {        
    let! result = tryDivide 5 3
    let mapped = result * 5
    return! multiplyIfEven 5 mapped
}
// result: None

// int option  
let resultSome = option {        
    let! result = tryDivide 6 3
    let mapped = result * 5
    return! multiplyIfEven 5 mapped
}
// result: Some 50
here