Add initial support for Try

[jlmorgan]

Requires an implementation of Tuple.

Must include the following:

• A Try type.
• The following static constructors:
  • failure a
  • success b
• The following static methods:
  • attempt :: (() -> a) → Try a: Wraps a successful execution in a Successand a thrownExeptionin aFailure`.
  • failures :: [Try a b] → [a]: Extracts from a list of Try all of the Failure elements in extracted order.
  • fromFailure :: a → Try a b → a: Extracts the value of a Failure; otherwise, returns the defaultValue.
  • fromSuccess :: b → Try a b → b: Extracts the value of a Success; otherwise, returns the defaultValue.
  • isFailure :: Try a b → Boolean: Determines whether or not the argument is a Failure.
  • isSuccess :: Try a b → Boolean: Determines whether or not the argument is a Success.
  • partitionTries :: [Try a b] → ([a], [b]): Partitions a list of Try into two lists. All Failure elements are extracted, in order, to the first position of the output. Similarly for the Success elements in the second position.
  • successes :: [Try a b] → [b]: Extracts from a list of Try all of the Success elements in extracted order.
  • tryMap :: ([a] → c) → (b → c) → Try a b → c: If the value is Failure a, apply the first function to [a]; otherwise, apply the second function to b.