impc:ti:memzone   scheme

(define impc:ti:memzone
  (lambda (ast)
    (define zone_returns_void? (impc:ti:check-memzone-void? ast))
    (if zone_returns_void?
        `(begin (push_new_zone ,(cadr ast))
                ,(if (= (length ast) 3) (caddr ast) (cadddr ast))
                (pop_zone)
                void)
        (begin
          (define resname (string->symbol (string-append "res" (number->string (modulo *xtm_mz_num* 100)))))
          (define zonename (string->symbol (string-append "zone" (number->string (modulo *xtm_mz_num* 100)))))
          (define newzname (string->symbol (string-append "newz" (number->string (modulo *xtm_mz_num* 100)))))
          (define rescopyname (string->symbol (string-append "rescopy" (number->string (modulo *xtm_mz_num* 100)))))
          (set! *xtm_mz_num* (+ *xtm_mz_num* 1))
          (if (or (> (length ast) 4)
                  (< (length ast) 3))
              (impc:compiler:print-bad-arity-error ast))
          `(begin (push_new_zone ,(cadr ast))
                  (let ((,resname ,(if (= (length ast) 3) (caddr ast) (cadddr ast)))
                        (,zonename (pop_zone))
                        (,newzname (llvm_peek_zone_stack)))
                    ;; this extra let seems redundant! BUT is needed
                    ;; because rescopyname should go in newzone not zonename
                    ;; i.e. needs to go into a *new* let after pop_zone is called
                    (let ((,rescopyname (zcopy ,resname ,zonename ,newzname)))
                      ,(if (= (length ast) 3)
                           `(llvm_zone_destroy ,zonename)
                           `(llvm_destroy_zone_after_delay ,zonename ,(caddr ast)))
                      ,rescopyname)))))))