A Simple (Custom) Lisp Interpreter

SCLI (A Simple (Custom) Lisp Interpreter) is a custom Lisp interpreter built in Python 2.7.x. It is meant to follow the language I developed that is an offshoot of Lisp.

Motivation

I have been interested in creating a programming language for the past year. So, I decided to read a bunch of manuals and then one day I finally tried writing one. This is the outcome of that day.

Usage

In the Python console, import the interpreter. Once the interpreter has been imported, run the read-evaluate-prompt-loop function like so:

python SCLI.py

The output of this should be

scli >

To exit the prompt type

scli > !quit

To use SCLI as a compiler instead of a repl, you can run it like so:

python SCLI.py file.scli

Now you’re ready to program in SCLI!

Releases

Currently, we have the alpha release here: github.com/sv4u/scli-interpreter/releases/tag/alpha

Install

To install, clone the repository into any directory you wish. Then, add that directory to your PATH so that you can execute scli from anywhere.

Documentation

To import the math package, type

scli > (import 'math)

To import a user package, type

scli > (user-import '*user library*)

Note: The file name must have no spaces in it and must end in “.scli”.

Current Libraries

The current libraries that have been implemented fully are:

• Math
• Strings

Libraries that are under development are:

• Solver

Libraries that have not been developed yet are:

• Statistics

Math Library

Some math functions that have been implemented in the math package are:

• Exponentiation
• Modular exponentiation
• sqrt(x)
• nroot(x, n): the nth root of x
• ceil(x) and floor(x)
• ln(x), log10(x), and log2(x)

Strings Library

Some string functions that have been implemented in the strings package are:

• Concatenation
• Substrings
• Character At
• Length
• Split on a regular expression

Solver Library

Some solver functions that have been implemented in the solver package are:

• Linear Solving
  • Format:

    (linear-solve a b)
    

    solves

    ax = b
    

• Quadratic Solving
  • Format:

    (quadraticr-solve a b c)
    

    solves

    ax^2 + bx = c
    

• Cubic Solving
  • Format:

    (linear-solve a b)
    

    solves

    ax^3 + bx^2 + cx = d
    

Note: this packages uses the SymPy library.

Contact

If you are interested in seeing this project grow or helping me, feel free to contact me at svvishnu@andrew.cmu.edu. I’m always looking for help.

License

MIT License

Copyright (c) 2017 Sasank Venkata Vishnubhatla

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

• Give full credit to the author
• Properly cite this repository

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.