https://github.com/calvin-l/minilang

A tiny, surprisingly turing-complete language
https://github.com/calvin-l/minilang

Last synced: 23 days ago
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A tiny, surprisingly turing-complete language

• Host: GitHub
• URL: https://github.com/calvin-l/minilang
• Owner: Calvin-L
• Created: 2012-02-06T08:21:33.000Z (almost 13 years ago)
• Default Branch: master
• Last Pushed: 2012-04-09T18:44:17.000Z (over 12 years ago)
• Last Synced: 2024-10-16T08:10:43.418Z (2 months ago)
• Language: Haskell
• Homepage:
• Size: 97.7 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README

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README

        

========================= MINI LANG =========================

---- Description

This is an implementation of a tiny turing-complete language.

The language has 3 constructs:

1. set a variable to zero

   x = 0

2. increment a variable

   x+

3. repeat for a specified number of times

   x { ... }

   (NOTE: if you increment x inside the loop, the number of

   iterations increases accordingly, thus allowing for

   infinite loops. Interestingly, changing this rule makes

   the language stop being turing complete.)

---- Additions

The interpreter (minii) also supports a few "syntactic sugar"

additions:

1. set a variable to an arbitrary integer

   x = 402311

   This is equivalent to saying "x = 0" and then incrementing

   x 402311 times.

2. defining functions

   def add(a, b) -> sum = {

       sum = 0

       a { sum+ }

       b { sum+ }

   }

   x = add(45, 29)

   The syntax is a little odd, but just means "this is a

   function that takes 'a' and 'b' and writes its result

   into 'sum.'"

3. builtin functions

   Since this language is very limited, implementations of

   even basic functions can be very slow. For that reason,

   rhe interpreter has builtin implementations of some

   other functions:

      - sub(a,b)           subtraction    (a-b)

      - div(a,b)           division       (a/b)

      - add(a,b)           addition       (a+b)

      - times(a,b)         multiplication (a*b)

      - pow(a,b)           exponentiation (a^b)

      - numFactors(a,b)    number of times b evenly divides a

   If you don't believe such a simple language could

   implement these on its own, check out the examples!

4. print functionality

   x = 12

   print(add(x, 45))

   A language without I/O is pretty boring. Minilang supports

   printing, and it shouldn't be too hard to hack in reading

   later as well.

---- Building

Minii can be built with GNU Make. You will need

 - GHC

 - Alex (http://www.haskell.org/alex/)

 - Happy (http://www.haskell.org/happy/)

Just type "make" to build.

---- Running

Minii takes input on stdin. For instance:

   $ ./minii < examples/cons.mini

---- Examples

There is one demo in the "examples" folder that builds

up to cons cells, implementing successor, subtraction,

division, and some other functions along the way.