Refactoring

This commit is contained in:
Justin Ethier 2016-04-30 02:16:22 -04:00
parent e2d158bdd6
commit 6ed5d735f6

View file

@ -782,55 +782,50 @@
;; FUTURE: append the empty (unprinted) value
;; instead of #f
#f)))
((define-c? exp) exp)
((define-syntax? exp)
;(trace:info `(define-syntax ,exp))
(let* ((name (cadr exp))
(trans (caddr exp))
(body (cadr trans)))
(cond
((tagged-list? 'syntax-rules trans) ;; TODO: what if syntax-rules is renamed?
(expand
`(define-syntax ,name ,(expand trans env))
env))
(else
(set! *defined-macros* (cons (cons name body) *defined-macros*))
;; Keep track of macros added during compilation.
;; Previous list should eventually go away once macros are
;; moved from that static list to libraries
(macro:add! name body)
(env:define-variable! name (list 'macro body) env)
;; Keep as a 'define' form so available at runtime
;; TODO: may run into issues with expanding now, before some
;; of the macros are defined. may need to make a special pass
;; to do loading or expansion of macro bodies
;; TODO: would it be better to use *define-macros* directly instead
;; of trying to define it here? that might help prevent issues where
;; an expand is called here before all macros are defined yet
;; - no, we need to do this here so code is carried though all transforms
;; (alpha, cps, closure, etc). otherwise code has to be interpreted during expansion
;;
`(define ,name ,(expand body env))))))
((app? exp)
(cond
;; TODO: could check for a define-syntax here and load into memory
;; if found. would then want to continue expanding. may need to
;; return some value such as #t or NULL as a placeholder, since the
;; define-syntax form would not be carried forward in the compiled code
((define-syntax? exp) ;; TODO: not good enough, should do error checking, and make sure list is big enough for cadr
;(trace:info `(define-syntax ,exp))
(let* ((name (cadr exp))
(trans (caddr exp))
(body (cadr trans)))
(cond
((tagged-list? 'syntax-rules trans) ;; TODO: what if syntax-rules is renamed?
(expand
`(define-syntax ,name ,(expand trans env))
env))
(else
(set! *defined-macros* (cons (cons name body) *defined-macros*))
;; Keep track of macros added during compilation.
;; Previous list should eventually go away once macros are
;; moved from that static list to libraries
(macro:add! name body)
(env:define-variable! name (list 'macro body) env)
;; Keep as a 'define' form so available at runtime
;; TODO: may run into issues with expanding now, before some
;; of the macros are defined. may need to make a special pass
;; to do loading or expansion of macro bodies
;; TODO: would it be better to use *define-macros* directly instead
;; of trying to define it here? that might help prevent issues where
;; an expand is called here before all macros are defined yet
;; - no, we need to do this here so code is carried though all transforms
;; (alpha, cps, closure, etc). otherwise code has to be interpreted during expansion
;;
`(define ,name ,(expand body env))))))
((define-c? exp) exp)
((symbol? (car exp))
(let ((val (env:lookup (car exp) env #f)))
(if (tagged-list? 'macro val)
(expand ; Could expand into another macro
(macro:expand exp val env)
env)
(map
(lambda (expr) (expand expr env))
exp))))
(else
(map
(lambda (expr) (expand expr env))
exp))))
((symbol? (car exp))
(let ((val (env:lookup (car exp) env #f)))
(if (tagged-list? 'macro val)
(expand ; Could expand into another macro
(macro:expand exp val env)
env)
(map
(lambda (expr) (expand expr env))
exp))))
(else
(map
(lambda (expr) (expand expr env))
exp))))
(else
(error "unknown exp: " exp))))
@ -885,10 +880,10 @@
((or (const? this-exp)
(prim? this-exp)
(ref? this-exp)
(quote? this-exp))
(quote? this-exp)
(define-c? this-exp))
(expand-body (cons this-exp result) (cdr exp) env))
((or (define? this-exp)
(define-c? this-exp)
(define-syntax? this-exp)
(lambda? this-exp)
(set!? this-exp)