Popularity
8.9
Stable
Activity
0.0
Stable
91
8
0

Monthly Downloads: 7
Programming language: Haskell
License: BSD 3-clause "New" or "Revised" License
Tags: Language     Compiler    

ntha alternatives and similar packages

Based on the "Compiler" category.
Alternatively, view ntha alternatives based on common mentions on social networks and blogs.

Do you think we are missing an alternative of ntha or a related project?

Add another 'Compiler' Package

README

Ntha Programming Language

Build Status zjhmale Haskell Hackage Hackage-Deps

a tiny statically typed functional programming language.

Installation

  • brew install z3
  • cabal install ntha

Features

  • Global type inference with optional type annotations.
  • Lisp flavored syntax with Haskell like semantic inside.
  • Support basic types: Integer, Character, String, Boolean, Tuple, List and Record.
  • Support unicode keywords.
  • Support destructuring.
  • ADTs and pattern matching.
  • Haskell like type signature for type checking.
  • Refined types (still in early stage, just support basic arithmetic operations and propositinal logic, here is some examples), based on z3-encoding
  • Module system (still in early stage, lack of namespace control).
  • Support pattern matching on function parameters.
  • Lambdas and curried function by default.
  • Global and Local let binding.
  • Recursive functions.
  • If-then-else / Cond control flow.
  • Type alias.
  • Do notation.
  • Begin block.

Future Works

Screenshot

cleantha

Example

(type Name String)
(type Env [(Name . Expr)])

(data Op Add Sub Mul Div Less Iff)

(data Expr
  (Num Number)
  (Bool Boolean)
  (Var Name)
  (If Expr Expr Expr)
  (Let [Char] Expr Expr)
  (LetRec Name Expr Expr)
  (Lambda Name Expr)
  (Closure Expr Env)
  (App Expr Expr)
  (Binop Op (Expr . Expr)))

(let op-map {:add +
             :sub -
             :mul *
             :div /
             :less <
             :iff =})

(arith-eval : (α → (β → Z)) → ((α × β) → (Maybe Expr)))
(ƒ arith-eval [fn (v1 . v2)]
  (Just (Num (fn v1 v2))))

(logic-eval : (α → (β → B)) → ((α × β) → (Maybe Expr)))
(ƒ logic-eval [fn (v1 . v2)]
  (Just (Bool (fn v1 v2))))

(let eval-op
  (λ op v1 v2 ⇒
    (match (v1 . v2)
      (((Just (Num v1)) . (Just (Num v2))) ⇒
        (match op
          (Add ⇒ (arith-eval (:add op-map) (v1 . v2)))
          (Sub ⇒ (arith-eval (:sub op-map) (v1 . v2)))
          (Mul ⇒ (arith-eval (:mul op-map) (v1 . v2)))
          (Div ⇒ (arith-eval (:div op-map) (v1 . v2)))
          (Less ⇒ (logic-eval (:less op-map) (v1 . v2)))
          (Iff ⇒ (logic-eval (:iff op-map) (v1 . v2)))))
      (_ ⇒ Nothing))))

(eval : [(S × Expr)] → (Expr → (Maybe Expr)))
(ƒ eval [env expr]
  (match expr
    ((Num _) ⇒ (Just expr))
    ((Bool _) → (Just expr))
    ((Var x) ⇒ (do Maybe
                 (val ← (lookup x env))
                 (return val)))
    ((If condition consequent alternative) →
          (match (eval env condition)
            ((Just (Bool true)) → (eval env consequent))
            ((Just (Bool false)) → (eval env alternative))
            (_ → (error "condition should be evaluated to a boolean value"))))
    ((Lambda _ _) → (Just (Closure expr env)))
    ((App fn arg) → (let [fnv (eval env fn)]
                      (match fnv
                        ((Just (Closure (Lambda x e) innerenv)) →
                            (do Maybe
                              (argv ← (eval env arg))
                              (eval ((x . argv) :: innerenv) e)))
                        (_ → (error "should apply arg to a function")))))
    ((Let x e1 in-e2) ⇒ (do Maybe
                          (v ← (eval env e1))
                          (eval ((x . v) :: env) in-e2)))
    ;; use fix point combinator to approach "Turing-complete"
    ((LetRec x e1 in-e2) → (eval env (Let "Y" (Lambda "h" (App (Lambda "f" (App (Var "f") (Var "f")))
                                                               (Lambda "f" (App (Var "h")
                                                                                (Lambda "n" (App (App (Var "f") (Var "f"))
                                                                                                 (Var "n")))))))
                                              (Let x (App (Var "Y") (Lambda x e1))
                                                     in-e2))))
    ((Binop op (e1 . e2)) => (let [v1 (eval env e1)
                                   v2 (eval env e2)]
                               (eval-op op v1 v2)))))

(begin
  (print "start")
  (let result (match (eval [] (LetRec "fact" (Lambda "n" (If (Binop Less ((Var "n") . (Num 2)))
                                                             (Num 1)
                                                             (Binop Mul ((Var "n") . (App (Var "fact")
                                                                                          (Binop Sub ((Var "n") . (Num 1))))))))
                                             (App (Var "fact") (Num 5))))
                ((Just (Num num)) ⇒ (print (int2str num)))
                (Nothing ⇒ (error "oops"))))
  (print result)
  (print "finish"))

License

Copyright © 2016 zjhmale

Distributed under the license BSD


*Note that all licence references and agreements mentioned in the ntha README section above are relevant to that project's source code only.