ref: 235a5a52f16165fc359f0cd8c3f8cbf970a90413
dir: /test/ast/rpasses.lsp/
; -*- scheme -*- (load "match.lsp") (load "asttools.lsp") (define missing-arg-tag '*r-missing*) ; tree inspection utils (define (assigned-var e) (and (pair? e) (or (eq (car e) '<-) (eq (car e) 'ref=)) (symbol? (cadr e)) (cadr e))) (define (func-argnames f) (let ((argl (cadr f))) (if (eq argl '*r-null*) () (map cadr argl)))) ; transformations (let ((ctr 0)) (set! r-gensym (lambda () (prog1 (symbol (string "%r:" ctr)) (set! ctr (+ ctr 1)))))) (define (dollarsign-transform e) (pattern-expand (pattern-lambda ($ lhs name) (let* ((g (if (not (pair? lhs)) lhs (r-gensym))) (n (if (symbol? name) name ;(symbol->string name) name)) (expr `(r-call r-aref ,g (index-in-strlist ,n (r-call attr ,g "names"))))) (if (not (pair? lhs)) expr `(r-block (ref= ,g ,lhs) ,expr)))) e)) ; lower r expressions of the form f(lhs,...) <- rhs ; TODO: if there are any special forms that can be f in this expression, ; they need to be handled separately. For example a$b can be lowered ; to an index assignment (by dollarsign-transform), after which ; this transform applies. I don't think there are any others though. (define (fancy-assignment-transform e) (pattern-expand (pattern-lambda (-$ (<- (r-call f lhs ...) rhs) (<<- (r-call f lhs ...) rhs)) (let ((g (if (pair? rhs) (r-gensym) rhs)) (op (car __))) `(r-block ,@(if (pair? rhs) `((ref= ,g ,rhs)) ()) (,op ,lhs (r-call ,(symconcat f '<-) ,@(cddr (cadr __)) ,g)) ,g))) e)) ; map an arglist with default values to appropriate init code ; function(x=blah) { ... } gets ; if (missing(x)) x = blah ; added to its body (define (gen-default-inits arglist) (map (lambda (arg) (let ((name (cadr arg)) (default (caddr arg))) `(when (missing ,name) (<- ,name ,default)))) (filter (lambda (arg) (not (eq (caddr arg) missing-arg-tag))) arglist))) ; convert r function expressions to lambda (define (normalize-r-functions e) (maptree-post (lambda (n) (if (and (pair? n) (eq (car n) 'function)) `(lambda ,(func-argnames n) (r-block ,@(gen-default-inits (cadr n)) ,@(if (and (pair? (caddr n)) (eq (car (caddr n)) 'r-block)) (cdr (caddr n)) (list (caddr n))))) n)) e)) (define (find-assigned-vars n) (let ((vars ())) (maptree-pre (lambda (s) (if (not (pair? s)) s (cond ((eq (car s) 'lambda) ()) ((eq (car s) '<-) (set! vars (list-adjoin (cadr s) vars)) (cddr s)) (#t s)))) n) vars)) ; introduce let based on assignment statements (define (letbind-locals e) (maptree-post (lambda (n) (if (and (pair? n) (eq (car n) 'lambda)) (let ((vars (find-assigned-vars (cddr n)))) `(lambda ,(cadr n) (let ,(map (lambda (v) (list v ())) vars) ,@(cddr n)))) n)) e)) (define (compile-ish e) (letbind-locals (normalize-r-functions (fancy-assignment-transform (dollarsign-transform (flatten-all-op && (flatten-all-op \|\| e)))))))