(module pattern-runtime mzscheme

  (require "list-utils.ss"
           "rep.ss"
           (lib "match.ss"))

  (provide (all-defined))

    
  (define (append/reverse code rest)
    (append (reverse code) rest))
  
  (define (pattern-failed name asm)
    (error 'asm-pattern
           "match failed for: ~a, reverse asm: ~a" name asm))
    
  ;; Pure asm transformers never use the data stack, only the asm
  ;; state. This lifts asm -> asm to (asm . stack) -> (asm . stack)
  
  (define (lift-transform  xform)
    (lambda  (old-code . stack)
      (pack (apply xform old-code) stack)))

  (define (lift-macro-executable  macro)
    (lambda input
      (check-macro-egg
       (apply macro input))))

  (define (lift-macro macro)
    (lift-macro-executable
     (lift-transform macro)))

  

  ;; Lifts an (asm . stack) -> (asm . stack) operation to one that
  ;; checks the assembler output for executable code = primitive
  ;; macro. If it's found, this macro is executed.

  (define (check-macro-egg output)
    (match output
           ((((and fn (= word? #t)) . asm) . stack)
            (apply fn `(,asm ,@stack)))
           (else
            output)))
)