Idris-style fallback for do comprehensions.
purescript-fallback allows you to short-circuit a do-comprehension.
spago install fallbackwithFallback do
i :: String <- Nothing |> const (Just 0)
result <- Int.fromString i |> const (Just 1)
pure result
-- Just 0
withFallback do
i :: String <- Just "abc" |> const (Just 0)
result <- Int.fromString i |> const (Just 1)
pure result
-- Just 1
withFallback do
i :: String <- Just "10" |> const (Just 0)
result <- Int.fromString i |> const (Just 1)
pure result
-- Just 10