('! #t)
('= #t)
('bool->int #t)
+ ('print #t)
(else #f)))
(cond
((list? x)
('let 'let)
('lambda 'lambda)
('closure 'closure) ; only available in codegen
+ ('static-string 'static-string) ; only available in codegen
(else 'app)))
((builtin? x) 'builtin)
((symbol? x) 'var)
((integer? x) 'int-literal)
- ((boolean? x) 'bool-literal)))
+ ((boolean? x) 'bool-literal)
+ ((string? x) 'string-literal)))
(define (ast-traverse f x)
(case (ast-type x)
('let `(let ,(map (lambda (x) (list (car x) (f (cadr x))))
(let-bindings x))
- ,@(map f (let-body e))))
+ ,@(map f (let-body x))))
('app (map f x))
- ('lambda `(lambda ,(lambda-args x) ,(f lambda-body)))
+ ('lambda `(lambda ,(lambda-args x) ,(f (lambda-body x))))
('if `(if ,@(map f (cdr x))))
(else x)))
-(define let-bindings cadr)
+(define (ast-collect f x)
+ (define (inner y) (ast-collect f y))
+ (case (ast-type x)
+ ['let (append (f x)
+ (flat-map inner (let-bindings x))
+ (flat-map inner (let-body x)))]
+ ['app (append (f x)
+ (flat-map inner x))]
+ ['lambda (append (f x)
+ (inner (lambda-body x)))]
+ ['if (append (f x)
+ (flat-map inner (cdr x)))]
+ [else (f x)]))
+
+(define (ast-find p x)
+ (define (inner y) (ast-find p y))
+ (define (any p x) (fold-left
+ (lambda (acc y) (if acc #t (p y)))
+ #f
+ x))
+ (define (either . fs)
+ (if (null? fs) #f
+ (if (car fs) (car fs)
+ (apply either (cdr fs)))))
+
+ (case (ast-type x)
+ ['let (either (p x)
+ (any inner (let-bindings x))
+ (any inner (let-body x)))]
+ ['app (either (p x)
+ (any inner x))]
+ ['lambda (either (p x)
+ (inner (lambda-body x)))]
+ ['if (either (p x) (any inner (cdr x)))]
+ [else (p x)]))
+
+(define (let-bindings e)
+ (define (extract x) ) ; TODO
+ (flat-map extract (cadr e))
(define let-body cddr)
(define (lambda? x)
(and (list? x) (eq? (car x) 'lambda)))
+
+(define (statement-type x)
+ (cond
+ [(and (list? x)
+ (eqv? (car x) 'data)) 'data]
+ [(and (list? x)
+ (eqv? (car x) 'define)) 'define]
+ [else 'expr]))
+
+(define (program-datas program)
+ (filter (lambda (x) (eqv? (statement-type x) 'data))
+ program))
+
+(define (program-defines program)
+ (filter (lambda (x) (eqv? (statement-type x) 'defines))
+ program))
+
+(define (program-body program)
+ `(let ()
+ ,@(filter (lambda (x) (eqv? (statement-type x) 'expr))
+ program)))
+
; for use in normalized form
(define lambda-arg caadr)
; for use elsewhere
(define lambda-args cadr)
(define lambda-body caddr)
+
+; utils
+(define (flat-map f x) (fold-left append '() (map f x)))
+(define (repeat x n) (if (<= n 0) '()
+ (cons x (repeat x (- n 1)))))
+
+
+(define-syntax push!
+ (syntax-rules ()
+ ((_ s x) (set! s (cons x s)))))
+
+(define-syntax pop!
+ (syntax-rules ()
+ ((_ s) (let ([x (car s)])
+ (set! s (cdr s))
+ x))))