#! /usr/bin/env mzscheme
#lang scheme  ;tested in PLT Scheme 4.1
;;
;; py.scm -- Python(ish) parser
;;

(require mzlib/defmacro)
(require mzlib/compat)  ;1+ 1-
(require mzlib/string)  ;read-from-string

(include "om-core.scm")


;; -----------------------------------------------
;; Python-ish grammar definition

(include "py-core.scm")
(include "py-grammar.scm")  ; Generated from py-grammar.bnf
(define grammar top)  ;alias


;; -----------------------------------------------
;; This is basically I/O plumbing....

(define (transform-grammar input-file output-file)
  ;(when (>= *LOGLEVEL* 2)
  ;  (printf ";GIVEN:~%~a~%" *s*)
  ;  (printf ";PARSING...~%") )
  
  (let* ((output (parse-from-file input-file))
         (outfile (open-output-file output-file #:exists 'replace)))
    (pretty-print-columns 80)
    (for-each
     (lambda (expr)
       (pretty-print expr outfile) (newline outfile))
     output) )
  
  (let ((remaining (substring *s* *i*)))
    (if (equal? remaining "")
        (when (>= *LOGLEVEL* 1) (printf "~%All input was parsed.~%"))
        (printf "~%WARNING: UNPARSED INPUT REMAINING:~%~a~%" remaining) ))
  )

     
;; -----------------------------------------------
;; Command line interface
;; (This is PLT-Scheme-specific; also, R6RS offers a command-line parser)
;;
(define verbosity  (make-parameter 0))
(define includes   (make-parameter null))

(command-line
 #:multi
 [("-v" "--verbose") "Verbose messages (-vv, -vvv for voluminous debug messages)"
                     (verbosity (1+ (verbosity)))]
 
 ; I don't think this is really necessary... and besides, I don't think
 ; (include) works at runtime; we'd have to (load) all the interdependent
 ; parser parts, or deal with namespaces...
 [("-i" "--include") scheme-file
                     "Include <scheme-file> ..."
                     (includes (cons scheme-file (includes)))]
 
 #:args
 (python-input-file output-scheme-file)

 (begin
   (set! *LOGLEVEL* (verbosity))
   (transform-grammar python-input-file output-scheme-file)
   ))