Lisp::Interpreter

Lisp interpreter implemented in Ruby.

Installation

Add this line to your application's Gemfile:

gem 'lisp-interpreter'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lisp-interpreter

Usage

booleans:

#t; #t

#f; #f

(not #t); #f

(equal? 5 5); #t

(if (<= 2 3) 'TRUE 'FALSE); TRUE

numbers:

(+ 1 2); 3

(- 1 2); -1

(* 1 2); 2

(/ 1 2); 0.5

(quotient 10 3); 3

(remainder 10 3); 1

(modulo 10 3); 1

(numerator 5); 5

(denominator 5); 1

(abs -10); 10

(add1 1); 2

(sub1 1); 0

(min 5 3 1 2 4); 1

(max 5 3 1 2 4); 5

(< 1 2); #t

(<= 2 2); #t

(> 1 2); #f

(>= 2 2); #t

strings:

(string-length "Hello world"); 11

(substring "Hello world" 4); "o world"

(string-upcase "sample"); "SAMPLE"

(string-downcase "SAMPLE"); "sample"

(string-contains? "Racket" "Rac"); #t

(string->list "Sample"); (#\S #\a #\m #\p #\l #\e)

(string-split "  foo bar  baz \r\n\t"); ("foo" "bar" "baz")

(string? "str"); #t

(string-replace "foo bar baz" "bar" "blah"); "foo blah baz"

(string-prefix? "Racket" "Rac"); #t

(string-sufix? "Racket" "cket"); #t

(string-join '(1 2) "potato"); "1potato2"

list and pairs:

(null? '()); #t

(cons 1 2); (1 . 2)

null; ()

(list 1 "s"); (1 "s")

(car (list #f 2 3 4)); #f

(cdr (list #f 2 3 4)); (2 3 4)

(cadr (list 1 2 3 4)); 2

(cdar (list (list 1 2) 2 3 4)); (2)

(list? (list 1 2)); #t

(pair? (list 1 2)); #t

(length (list 1 2 3)); 3

(reverse (list 1 2 3)); (3 2 1)

(remove 1 (list 1 2 3)); (2 3)

(shuffle (list 1 2 3)); permutation of [1, 2, 3]

(map (lambda (n)(+ 1 n)) '(1 2 3 4)); (2 3 4 5)

(foldl cons '() '(1 2 3 4 5)); (5 4 3 2 1)

(foldr cons '() '(1 2 3 4 5)); (1 2 3 4 5)

(filter (lambda (x) (<= x 3)) '(1 2 3 4 5)); (1 2 3)

(member 2 (list 1 2 3 4)); (2 3 4)

functions and procedures:

(lambda (x) (* 2 x)); <#Closure>

((lambda (x) (* 2 x)) 5); 10

(apply + '(1 2 3)); 6

((compose fn1 fn2) val); (fn1 (fn2 val))

(compose fn1 fn2); #<Closure>

errors:

(+ 1 2 #t); "Invalid data type, expected <number> got <boolean>"

(string-length 123); "Invalid data type, expected <string> got <number>"

(string-join "SAMPLE"); "Invalid data type, expected <list> got <string>"

(substring "sample"); "Incorrect number of arguments, expected [2, 3] got 1"

(x); "x is not a function"

x; "Unbound symbol x"

other:

(define x 5); 5

(define x (lambda (x) (* 2 x))); <#Closure>

(define (even? x) (if (equal? (remainder x 2) 0) #t #f)); <#Closure>

(define map foldl); <Function foldl>

(even? 4); #t

(even? 3); #f

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/zaki1993/Ruby-Project/lisp-interpreter. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the Lisp::Interpreter project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.