coco

A simple Scheme interpreter, created as a Haskell exercise project. It only implements a subset of R5RS for now. Needs proper testing still as well.

Install

1. Prerequisites: Stack.
2. Build it:

$ stack build

3. Run it:
   • As an interactive interpreter:

   $ make run

   • Use it to run a Scheme (.scm) file:

   $ stack exec coco-exe -- FILENAME ARG1 ARG2 ARG3

   Args are passed into the program in the file as a list bound to a variable called args.

What can it do?

Types

• Lists (:information_desk_person:)
• Dotted Lists
• Numbers (Integers, signed)
• Floats (signed) (Note that type isn't strictly enforced in some operations, like addition, etc)
• Strings
• Bools
• Characters
• Functions

All supported types (and errors) are in the ValueLib module. Numbers can be written as decimals, hexadecimals, octals, or binary, given the proper Scheme notation.

Patterns

• Primitive patterns (patterns that are the types themselves).
• Quoted types (e.g. '(1 2 3))
• If conditions.
• Set and define variables (e.g. (set! x 3) or (define x 3))
• Define functions.
• Lambda functions.
• Load file (e.g. (load "test.scm")).
• Evaluate function (e.g. (func 1 2)).

Built-in Functions

• +
• -
• *
• /
• mod
• quotient
• remainder
• number?
• string?
• boolean?
• list?
• zero?
• char?
• symbol?
• not
• length
• symbol->string
• string->symbol
• list->string
• string->list
• =
• /=
• <
• >
• <=
• >=
• &&
• ||
• string=?
• string>?
• string<?
• string<=?
• string>=?
• char=?
• char>?
• char<?
• char>=?
• char<=?
• cons
• car
• cdr
• eq?
• eqv?
• make-string
• string
• string-length
• string-ref
• substring
• string-append
• string-copy
• apply
• open-input-file
• open-output-file
• close-input-port
• close-output-port
• read
• write
• read-contents
• read-all

The complete list of built-in functions can be found in primitives and ioPrimitives in the Eval module.

References

• R5RS (Scheme standard doc)
• Write Yourself a Scheme In 48 Hours (Book)
• Haskell Wiki and official docs in general, to adapt depracated methods/patterns and as a general reference.