jarrett / unexceptional

Unexceptional

Provides a Result class for more elegant, exception-free error handling. Especially useful for processing input that could be invalid for many different reasons.

API Docs

http://www.rubydoc.info/github/jarrett/unexceptional/master/Unexceptional/Result

Examples

Result.try(
  ->    { Result.ok 2 },
  ->(i) { Result.ok 3 * i }
)
# => Result.ok(6)


Result.try(
  ->    { Result.ok 2 },
  ->(_) { Result.err :uh_oh },
  ->(i) { Result.ok 3 * i }
)
# => Result.err(:uh_oh)


Result.try(
  ->         { Result.ok [1, 2] },
  ->((a, b)) { Result.ok a + b }
)
# => Result.ok(3)


Result.map_while([1, 2]) do |i|
  Result.ok i * 2
end
# => Result.ok([1, 2])


Result.map_while([1, 2, 3]) do |i|
  if i == 2
    Result.err '2 is invalid'
  elsif i == 3
    raise 'This is never executed because Result.map_while aborts on the previous element.'
  else
    Result.ok i * 2
  end
end
# => Result.err('2 is invalid')


Result
  .err(:uh_oh)
  .and_then { 'This block never executes' }
# => Result.err(:uh_oh)


Result
  .ok('This value gets dropped')
  .and_then(Result.ok('This is the final value'))
# => Result.ok('This is the final value')


Result
  .ok(3)
  .and_then { |v| v * 2 }
# => Result.ok(6)


Result
  .ok('This value gets dropped')
  .and_then
# => Result.ok