PornLisp

A Lisp dialect implementation in OCaml5

Introduction

This project is the MLisp interpreter.

• This project is developed entirely in OCaml 5.0 (Current is OCaml5.0.0~alpha1)

Demo

• REPL

MLisp v0.1.2 (main, Aug 2 2022, 9:52:17) [OCaml 5.0.0~alpha1]

> (env)
- : pair = ((mergesort . #<closure>) (merge . #<closure>) (drop . #<closure>) (take . #<closure>) (length . #<closure>) (null? . #<closure>) (getline . #<closure>) (println . #<closure>) (space .  ) (newline . 
) (cons . #<primitive:pair>) (caddar . #<closure>) (cadar . #<closure>) (caddr . #<closure>) (cadr . #<closure>) (caar . #<closure>) (o . #<closure>) (eval. . #<closure>) (lookup. . #<closure>) (caddar . #<closure>) (cadar . #<closure>) (caddr . #<closure>) (cadr . #<closure>) (caar . #<closure>) (o . #<closure>) (zip. . #<closure>) (list. . #<closure>) (append. . #<closure>) (cons . #<primitive:pair>) (not. . #<closure>) (and. . #<closure>) (null. . #<closure>) (cat . #<primitive:cat>) (int->char . #<primitive:int->char>) (print . #<primitive:print>) (getchar . #<primitive:getchar>) (sym? . #<primitive:sym?>) (atom? . #<primitive:atom?>) (eq . #<primitive:eq>) (cdr . #<primitive:cdr>) (car . #<primitive:car>) (pair . #<primitive:pair>) (list . #<primitive:list>) (<= . #<primitive:<=>) (>= . #<primitive:>=>) (> . #<primitive:>>) (< . #<primitive:<>) (= . #<primitive:=>) (mod . #<primitive:mod>) (/ . #<primitive:/>) (* . #<primitive:*>) (- . #<primitive:->) (+ . #<primitive:+>) (empty-symbol . ))

> (+ 3 5)
- : int = 8

> (and #t #f)
- : boolean = #f

> (and #f #f)
- : boolean = #f

> (or #f #t)
- : boolean = #t

> (or #f #f)
- : boolean = #f

> (if (and #t #f) 3 4)
- : int = 4

> (if (or #t #f) 3 4)
- : int = 3

> (setq x 3)
- : int = 3

> (env)
- : pair = ((x . 3) (mergesort . #<closure>) (merge . #<closure>) (drop . #<closure>) (take . #<closure>) (length . #<closure>) (null? . #<closure>) (getline . #<closure>) (println . #<closure>) (space .  ) (newline . 
) (cons . #<primitive:pair>) (caddar . #<closure>) (cadar . #<closure>) (caddr . #<closure>) (cadr . #<closure>) (caar . #<closure>) (o . #<closure>) (eval. . #<closure>) (lookup. . #<closure>) (caddar . #<closure>) (cadar . #<closure>) (caddr . #<closure>) (cadr . #<closure>) (caar . #<closure>) (o . #<closure>) (zip. . #<closure>) (list. . #<closure>) (append. . #<closure>) (cons . #<primitive:pair>) (not. . #<closure>) (and. . #<closure>) (null. . #<closure>) (cat . #<primitive:cat>) (int->char . #<primitive:int->char>) (print . #<primitive:print>) (getchar . #<primitive:getchar>) (sym? . #<primitive:sym?>) (atom? . #<primitive:atom?>) (eq . #<primitive:eq>) (cdr . #<primitive:cdr>) (car . #<primitive:car>) (pair . #<primitive:pair>) (list . #<primitive:list>) (<= . #<primitive:<=>) (>= . #<primitive:>=>) (> . #<primitive:>>) (< . #<primitive:<>) (= . #<primitive:=>) (mod . #<primitive:mod>) (/ . #<primitive:/>) (* . #<primitive:*>) (- . #<primitive:->) (+ . #<primitive:+>) (empty-symbol . ))

> (+ x 7)
- : int = 10

> (apply pair (list 3 4))
- : pair = (3 . 4)

> (pair 5 6)
- : pair = (5 . 6)

> (setq x (lambda (y) (+ y 1)))
- : closure = #<closure>

> (x 10)
- : int = 11

> (defun x (y) (+ y 1))
- : closure = #<closure>

> (x 10)
- : int = 11

> (defun f (x)
    (if (< x 2)
      1
      (g (- x 1))))
- : closure = #<closure>

> (defun g (x)
    (if (< x 2)
      3
      (f (- x 2))))
- : closure = #<closure>

> (f 10)
- : int = 1

> (g 10)
- : int = 3

> (f (g 10))
- : int = 1

> (let ((x 10)
        (y 20))
    (+ x y))
- : int = 30

> (let* ((x 10)
         (y x))
    (+ x y))
- : int = 20

> (letrec ((f (lambda (x) (g (+ x 1))))
           (g (lambda (x) (+ x 3))))
    (f 0))
- : int = 4

> y

+----------------------------------------------------------------------------
| From : "stdin" , Line: 39 , Column: 0
| | Error: Not found : y
| | Help : Accessing an identifier that has not been defined in the context.
+----------------------------------------------------------------------------
> ())
- : nil = nil

> 
+---------------------------------------------------------------------------------
| From : "stdin" , Line: 39 , Column: 3
| | Error: Syntax error -> Unexcepted character : ')'
| | Help : Usually triggered by wrong characters, such as extra parentheses, etc.
+---------------------------------------------------------------------------------
> 

• File MLisp supports loading programs from files since version 0.1.2, just pass the MLisp source file as the first argument to mlisp, For example:

File: 05_mutually_recursive_functions.mlisp

 1 │ (defun f (x)
 2 │   (if (< x 2)
 3 │       1
 4 │       (g (- x 1))))
 5 │ 
 6 │ (defun g (x)
 7 │   (if (< x 2)
 8 │       3
 9 │       (f (- x 2))))
10 │ 
11 │ (println (f 10))

$ mlisp 05_mutually_recursive_functions.mlisp 
1

Compared to REPL, the error message of the file will be more colorful, For example:

File: end_test_errors.mlisp:

 1 │ (println "Please don't be nervous, we are just testing the display of error messages")
 2 │ 
 3 │ (defun f (x)
 4 │   (if (< x 2)
 5 │       1
 6 │       (g (- x 1))))
 7 │ 
 8 │ (defun g (x)
 9 │   (if (< x 2)
10 │       3
11 │       (f (- x 2))))
12 │ 
13 │ (f g)

$ mlisp end_test_errors.mlisp 
"Please don\'t be nervous, we are just testing the display of error messages"

+---------------------------------------------------------------------------------------------------------------------------------------
| From : "end_test_errors.mlisp" , Line: 31 , Column: 5
|------> (f g)
| +----------^
| | Error: Parse error -> Type error : (< int int)
| | Help : Possible type error due to a function call with parameters of a type different from that specified in the function definition.
+---------------------------------------------------------------------------------------------------------------------------------------

Build

From source

Since this project is developed using OCaml5, you need to install the OCaml5 environment. The current latest OCaml5 Release version is OCaml5.0.0~alpha1.You can install this version via opam update && opam switch create 5.0.0~alpha1 --repositories=default,beta=git+https://github.com/ocaml/ocaml-beta-repository.git to install this version of OCaml environment.

• This project is built with dune, you can install it with opam install dune.
• This project relies on camlp-streams for streaming operations, this library that is usually builtin, if you don't have, you can install it via opam install camlp-streams. See details: https://discuss.ocaml.org/t/module-stream-removed-from-5-0-standard-library
• This project relies on ocolor for error message printing, you can install it via opam install ocolor

1. Build and install with ocaml pom.ml install
2. Run all tests via ocaml pom.ml test
3. Execute via mlisp

NOTE: Uninstall via ocaml pom.ml uninstall

License

Copyright (C) 2022 Muqiu Han

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see https://www.gnu.org/licenses/.