GoScheme

Just another shceme interpreter written in Go.

Installation

go get github.com/xrlin/goscheme/cmd/goscheme

Or you can download the corresponding pre-compiled executable file in release page.

Usage

# Just run goscheme to enter interactive shell
goscheme

# Run a scheme file
goscheme test.scm

Examples

• Calculate nth fibonacci number

  ; calculate nth fibonacci number
  (define (fib n)
     (if (<= n 2) 1 (+ (fib (- n 1)) (fib (- n 2)))))
  
  (fib 10)
   
  ;#=> 55
   
  ; calculate nth fibnacci number in tail recursion
  (define (fib2 n)
     (begin (define (fib-iter a b n)
           (if (= n 0) b (fib-iter b (+ a b) (- n 1))))
     (fib-iter 0 1 (- n 1))))
  (fib2 30)
  ;#=>832040
  

• Mutually recursion

  (letrec (
      (zero? (lambda (x) (= x 0)))
      (even?
      (lambda (n)
      (if (zero? n)
          #t
          (odd? (- n 1)))))
      (odd?
          (lambda (n)
          (if (zero? n)
              #f
              (even? (- n 1))))))
  (even? 88))
  ;#=>#t
  

Explore example.scm for more examples.

Features

• Interactive REPL shell

• Tail recursion optimization

• Lazy evaluation

• Short circut logic

• Type: String, Number, Quote, LambdaProcess, Pair, Bool ...

• syntax, builtin functions and procedures

  load define let let* letrec begin lambda and or not if cond delay map reduce force + - * / = cons list append list-length list-ref quote null? ' eval apply set! set-cdr! set-car! ... etc

Though it is a toy project just for fun and practice, Feel free to open an issue or make a merge request is you find bugs or have some suggestions.

Happy coding...