_try

Runs a function that may raise an exception, trapping it. Returns an Ok with the return value of the function, if it has finished successfully, or an Error with the raised exception.

Signature

_try(f)

Type(what is this?)

forall a, b: (() => b :: throws a) => Result a b

Documentation

Runs a function that may raise an exception, trapping it. Returns an Ok with the return value of the function, if it has finished successfully, or an Error with the raised exception.

Example:

function successor(natural) {
  if (natural < 0) {
    throw `Not a natural number: ${natural}`;
  } else {
    return natural + 1;
  }
}

const Result = require('folktale/result');

Result.try(() => successor(-1));
// ==> Result.Error('Not a natural number: -1')

Result.try(() => successor(1));
// ==> Result.Ok(2)

Properties

Source Code

Defined in source/result/try.js at line 20, column 0

(f) => {
  try {
    return Ok(f());
  } catch (e) {
    return Error(e);
  }
}