https://github.com/wongsingfo/SimpleLisp

A dirty implement of scheme interpreter :)
https://github.com/wongsingfo/SimpleLisp

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A dirty implement of scheme interpreter :)

• Host: GitHub
• URL: https://github.com/wongsingfo/SimpleLisp
• Owner: wongsingfo
• Created: 2016-05-27T11:51:57.000Z (about 8 years ago)
• Default Branch: master
• Last Pushed: 2016-09-15T02:19:30.000Z (almost 8 years ago)
• Last Synced: 2024-01-29T06:17:51.323Z (5 months ago)
• Language: C
• Homepage:
• Size: 36.1 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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• AwesomeInterpreter - SimpleLisp

README

        
# SimpleLisp

An simple implement of scheme lisp :)

# Todo

- string type

- garbage collection

- lazy evaluate

# Brief explanation

## Compile 

```

gcc control.c symbol.c number.c exception.c eval.c parser.c atom.c -Wall -O2

```

## install package

These packages must be installed in order! 

Install `exception` first, then the `symbol` & `number`, then the `atom`, etc..

```

-- parser

-- eval

  -- atom

    -- symbol

    -- number

      -- exception

```

# Test

## lambda

```

> (define x 2)

< ()

> ((lambda (f)

           ((lambda (x)     

                    (f 3))

            4))

   (lambda (y) (+ x y)))

< 5

```

The representation of `lambda` and `environment` is shown below.

```

> (define f (lambda (x y) (+ x y)))

< ()

> f

< (lambda_tag (x y) (+ x y) ...env...)

```

## cons, car, cdr

```

> (define cons (lambda (x y) 

    (lambda (c)

      (if (= c 0) x y))))

< ()

> (define car (lambda (x)

    (x 0)))

< ()

> (define cdr (lambda (x)

    (x 1)))

< ()

> (define x (cons 100 200))

< ()

> (cdr x)

< 200

> (car x)

< 100

```

## stream

```

(define-syntax cons-stream

  (syntax-rules ()

    ((cons-stream a b)

     (cons a (lambda () b))))) 

```

`cons-tream` is a primitive procedure, so the code above is not needed.

```

> (define add-streams

  (lambda (x y)

    (cons-stream

      (+ (stream-car x) (stream-car y))

      (add-streams (stream-cdr x) (stream-cdr y)))))

< ()

> (define stream-car (lambda (stream) (car stream)))

< ()

> (define stream-cdr (lambda (stream) ((cdr stream))))

< ()

> (define fibs (cons-stream 0 (cons-stream 1 (add-streams (stream-cdr fibs) fibs))))

< ()

> (define stream-iter 

  (lambda (stream i)

    (if (= i 0) 

        (stream-car stream)

        (stream-iter (stream-cdr stream) (+ i -1)))))

< ()

> (stream-iter fibs 22)

< 17711

```