Monadic Parser Combinator written in swift

A simple haskell-style monadic combinator-based parser written in Swift.

A minium interpreter is also implemented in this tiny project.

Try

let c: String = " i = 0 print i sum = 0 while i<100  {sum=sum+i i=i+1 }   print sum"
let ast = (space() >>= {_ in com()}).p(c)[0].0
interpreter(ast)

Features:

• Pure parser process without any side effects.
• Implemented with Haskell-like monad based operator return,>>=, and zero.
• Easy to scale up to deal with complex language parse and interprete.
• Concise code which extremely easy to understand and modify.

Drawbacks:

• In order to keep it simple and stupid, there are lots of string construct operation, which has pool performance.
• Same reason as above, there are lots of direct array construct/deconstruct operation, which has pool performance, consider replace it with swift lazy evaluation feature such as AnyGenerator/AnySequence if u want imporve it.