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error ​

Handy alias to create an Left with the info fixed to "error". Useful to signal a generic error without manually providing the info.

TIP

error is equivalent to left("error", value). To understand the full mechanics (custom info, pattern matching), see the left page.

Interactive example ​

Syntax ​

typescript
function error<
	const GenericInput extends unknown
>(
  input: GenericInput
): Error<GenericInput>

Parameters ​

  • input: Data to attach to the error (message, object, context...)

Return value ​

An Left<"error", GenericInput> that you can consume with E.isLeft, E.whenHasInformation, or E.hasInformation(result, "error").

Use cases ​

  • Signal a generic error when you do not need specialized information.
  • Harmonize your returns with E.success when there is only one type of success.

See also ​

  • left – Generic version with custom info.
  • fail – Error without payload (left("fail")).
  • success – Right counterpart with the "success" info.

Released under the MIT license.