mplisp

A C++ interpreter for a simple LISP dialect, made for educational purposes.

I wrote about what I learned with this project here.

Features

The following language features are supported:

• Data types: Number, Symbol, Boolean, List
• Lexical scope
• Arithmetic functions +, -, *, /
• Number comparison functions >, <, >=, <=, =
• lambda functions
• define
• quote or ' to quote data
• if for conditional evaluation
• car, cdr, and cons for list manipulation
• boolean function empty? to check if a list is empty

Standard Library:

• filter, map, max, and sum.
• boolean functions and and or.

Non-Features

• Garbage collection

  • When I designed this interpreter, I wrote it as a recursive tree-walking AST interpreter with each new expression being new on the heap. I have tried messing around with implementing garbage collection but it has proven to be a lot harder than I imagined and quite difficult to debug.

• Strings and characters