Walter Programming Language

Programming language operating on potentially unbounded streams of integers.

Installation

Language is built in Haskell hence to install you will need: ghc compiler, lexical analyzer alex and parser generator happy.

Download walter_1.0 directory then run the following command inside.

make

In order to run a program type the following.

./myinterpreter <your_file> < <your_input>

Example

For full documentation please refer to Walter User Guide included in this repository.

Read two streams of data. Interpret first as integer second as boolean. If boolean is true then increment the number.

Example1: {}

-- define input
[a : Int, b : Bool] -> if(b){
                       [a + 1]; -- output a + 1
                       [a + 2]; -- output a + 2
                       }

To run the function place it inside Main.

Main:
     stdin >> Example1 >> stdout

Example input and output.

Input:  Output:
1 1      2
2 0      3
3 1      4
         5

Piping feature

In Walter you can define multiple functions and then pipe them together.
We are going to illustrate it with a simple example.

IncrementConstant: {k  : Int = 5;}
[a : Int] -> [a + k]

Negate: {}
[a : Int] -> [-a]

Main:
stdin >> SumConstant >> Negate >> stdout

Input:  Output:
 1       -6
-2        7
 3       -8

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

MIT