lollipop is a general purpose, functional programming language with support for linear types. This is a bachelor thesis project at Chalmers University of Technology, Gothenburg.

Goal

The main goal is to develop a proof-of-concept of linear types in a basic functional language. This is to enable easy access to the concept for developers that are interested in learning about linear types, in a practical environment.

The project thesis can be found HERE!

Running programs in lollipop

The lollipop interpreter, loli, (loli.hs) is used to load and run programs written in lollipop (.lp).

Requirements

The lollipop interpreter is built in Haskell and therefore requires the Glasgow Haskell Compiler, GHC to run.

Running the lollipop interpreter

To run the lollipop interpreter, fire up a terminal, move to the lollipop root directory and execute

runghc -iAST/:grammar/ loli.hs

It will take some time loading the interpreter, but when it's done the terminal will prompt:

>

From here you can load lollipop programs (ending with .lp) by using :l, reloading programs using :r and leaving the interpreter by :q.

E.g: Loading of the program sugar (filename sugar.lp):

>:l sugar
Successfully loaded sugar
sugar>

From here you can execute functions and expressions in the loaded program

E.g: Running some basic functions in sugar

 >:l sugar
Successfully loaded sugar
sugar> fac 5
120
sugar> head [7,8,9]
7
sugar> map (\x -> x+2) [4,6,8]
[6,8,10]

Disclaimer

As for now the lollipop interpreter is in a beta-phase and syntax-errors and unsuccessfully loaded programs can cause it to crash. In this case, restart it using the same command again:

runghc -iAST/:grammar/ loli.hs

In rare cases the interpreter gets stuck in an evaluation loop. If the interpreter does this, try ending the process using ctrl+c, or by killing the ghc-process.