kat

kat is a basic scheme interpreter written in C++. In order to build kat from sources, the following are required:

• cmake

If all requirements are met, perform the following steps:

mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release -G Ninja ../
ninja

You can run kat by typing:

./kat

and then you can type the well known Y-combinator to get yourself started :)

(define Y
  (lambda (f)
    ((lambda (x) (f (lambda (y) ((x x) y))))
     (lambda (x) (f (lambda (y) ((x x) y)))))))

(define factorial
  (Y (lambda (fact)
       (lambda (n)
         (if (= n 0)
           1
           (* n (fact (- n 1))))))))

(write (factorial 5))

kat is a work in progress and under heavy construction. Since no error handling is implemented, the interpreter will exit (or crash) on bad input.

The following functions are implemented:

• null?
• boolean?
• symbol?
• integer?
• char?
• string?
• pair?
• procedure?
• char->integer
• integer->char
• number->string
• string->number
• symbol->string
• string->symbol
• +
• -
• *
• quotient
• remainder
• =
• <
• >
• cons
• car
• cdr
• set-car!
• set-cdr!
• list
• eq?
• apply
• interaction-environment
• null-environment
• environment
• eval
• load
• open-input-port
• close-input-port
• input-port?
• open-output-port
• close-output-port
• output-port?
• read
• read-char
• peek-char
• write
• write-char
• eof-object?
• error
• display

changes

• v0.26 Added the display primitive procedure.
• v0.23 A very simple object pooling strategy is implemented. The number of memory allocations decreased dramatically.
• v0.22 A mark & sweep garbage collector is now used for memory hadling
• v0.21 Added stdlib.scm. This file contains more function definitions written in scheme.
• v0.20 Some basic I/O functions added.