;;; ccl.el --- CCL (Code Conversion Language) compiler

;; Copyright (C) 1995 Electrotechnical Laboratory, JAPAN.
;; Licensed to the Free Software Foundation.

;; Keywords: CCL, mule, multilingual, character set, coding-system

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; CCL (Code Conversion Language) is a simple programming language to
;; be used for various kind of code conversion.  CCL program is
;; compiled to CCL code (vector of integers) and executed by CCL
;; interpreter of Emacs.
;;
;; CCL is used for code conversion at process I/O and file I/O for
;; non-standard coding-system.  In addition, it is used for
;; calculating a code point of X's font from a character code.
;; However, since CCL is designed as a powerful programming language,
;; it can be used for more generic calculation.  For instance,
;; combination of three or more arithmetic operations can be
;; calculated faster than Emacs Lisp.
;;
;; Syntax and semantics of CCL program is described in the
;; documentation of `define-ccl-program'.

;;; Code:

(defgroup ccl nil
  "CCL (Code Conversion Language) compiler."
  :prefix "ccl-"
  :group 'i18n)

(defconst ccl-command-table
  [if branch loop break repeat write-repeat write-read-repeat
      read read-if read-branch write call end
      read-multibyte-character write-multibyte-character
      translate-character
      iterate-multiple-map map-multiple map-single]
  "Vector of CCL commands (symbols).")

;; Put a property to each symbol of CCL commands for the compiler.
(let (op (i 0) (len (length ccl-command-table)))
  (while (< i len)
    (setq op (aref ccl-command-table i))
    (put op 'ccl-compile-function (intern (format "ccl-compile-%s" op)))
    (setq i (1+ i))))

(defconst ccl-code-table
  [set-register
   set-short-const
   set-const
   set-array
   jump
   jump-cond
   write-register-jump
   write-register-read-jump
   write-const-jump
   write-const-read-jump
   write-string-jump
   write-array-read-jump
   read-jump
   branch
   read-register
   write-expr-const
   read-branch
   write-register
   write-expr-register
   call
   write-const-string
   write-array
   end
   set-assign-expr-const
   set-assign-expr-register
   set-expr-const
   set-expr-register
   jump-cond-expr-const
   jump-cond-expr-register
   read-jump-cond-expr-const
   read-jump-cond-expr-register
   ex-cmd
   ]
  "Vector of CCL compiled codes (symbols).")

(defconst ccl-extended-code-table
  [read-multibyte-character
   write-multibyte-character
   translate-character
   translate-character-const-tbl
   nil nil nil nil nil nil nil nil nil nil nil nil ; 0x04-0x0f
   iterate-multiple-map
   map-multiple
   map-single
   ]
  "Vector of CCL extended compiled codes (symbols).")

;; Put a property to each symbol of CCL codes for the disassembler.
(let (code (i 0) (len (length ccl-code-table)))
  (while (< i len)
    (setq code (aref ccl-code-table i))
    (put code 'ccl-code i)
    (put code 'ccl-dump-function (intern (format "ccl-dump-%s" code)))
    (setq i (1+ i))))

(let (code (i 0) (len (length ccl-extended-code-table)))
  (while (< i len)
    (setq code (aref ccl-extended-code-table i))
    (if code
	(progn
	  (put code 'ccl-ex-code i)
	  (put code 'ccl-dump-function (intern (format "ccl-dump-%s" code)))))
    (setq i (1+ i))))

(defconst ccl-jump-code-list
  '(jump jump-cond write-register-jump write-register-read-jump
    write-const-jump write-const-read-jump write-string-jump
    write-array-read-jump read-jump))

;; Put a property `jump-flag' to each CCL code which execute jump in
;; some way.
(let ((l ccl-jump-code-list))
  (while l
    (put (car l) 'jump-flag t)
    (setq l (cdr l))))

(defconst ccl-register-table
  [r0 r1 r2 r3 r4 r5 r6 r7]
  "Vector of CCL registers (symbols).")

;; Put a property to indicate register number to each symbol of CCL.
;; registers.
(let (reg (i 0) (len (length ccl-register-table)))
  (while (< i len)
    (setq reg (aref ccl-register-table i))
    (put reg 'ccl-register-number i)
    (setq i (1+ i))))

(defconst ccl-arith-table
  [+ - * / % & | ^ << >> <8 >8 // nil nil nil
   < > == <= >= != de-sjis en-sjis]
  "Vector of CCL arithmetic/logical operators (symbols).")

;; Put a property to each symbol of CCL operators for the compiler.
(let (arith (i 0) (len (length ccl-arith-table)))
  (while (< i len)
    (setq arith (aref ccl-arith-table i))
    (if arith (put arith 'ccl-arith-code i))
    (setq i (1+ i))))

(defconst ccl-assign-arith-table
  [+= -= *= /= %= &= |= ^= <<= >>= <8= >8= //=]
  "Vector of CCL assignment operators (symbols).")

;; Put a property to each symbol of CCL assignment operators for the compiler.
(let (arith (i 0) (len (length ccl-assign-arith-table)))
  (while (< i len)
    (setq arith (aref ccl-assign-arith-table i))
    (put arith 'ccl-self-arith-code i)
    (setq i (1+ i))))

(defvar ccl-program-vector nil
  "Working vector of CCL codes produced by CCL compiler.")
(defvar ccl-current-ic 0
  "The current index for `ccl-program-vector'.")

;; Embed integer DATA in `ccl-program-vector' at `ccl-current-ic' and
;; increment it.  If IC is specified, embed DATA at IC.
(defun ccl-embed-data (data &optional ic)
  (if ic
      (aset ccl-program-vector ic data)
    (let ((len (length ccl-program-vector)))
      (if (>= ccl-current-ic len)
	  (let ((new (make-vector (* len 2) nil)))
	    (while (> len 0)
	      (setq len (1- len))
	      (aset new len (aref ccl-program-vector len)))
	    (setq ccl-program-vector new))))
    (aset ccl-program-vector ccl-current-ic data)
    (setq ccl-current-ic (1+ ccl-current-ic))))

;; Embed pair of SYMBOL and PROP where (get SYMBOL PROP) should give
;; proper index number for SYMBOL.  PROP should be
;; `translation-table-id', `code-conversion-map-id', or
;; `ccl-program-idx'.
(defun ccl-embed-symbol (symbol prop)
  (ccl-embed-data (cons symbol prop)))

;; Embed string STR of length LEN in `ccl-program-vector' at
;; `ccl-current-ic'.
(defun ccl-embed-string (len str)
  (let ((i 0))
    (while (< i len)
      (ccl-embed-data (logior (ash (aref str i) 16)
			       (if (< (1+ i) len)
				   (ash (aref str (1+ i)) 8)
				 0)
			       (if (< (+ i 2) len)
				   (aref str (+ i 2))
				 0)))
      (setq i (+ i 3)))))

;; Embed a relative jump address to `ccl-current-ic' in
;; `ccl-program-vector' at IC without altering the other bit field.
(defun ccl-embed-current-address (ic)
  (let ((relative (- ccl-current-ic (1+ ic))))
    (aset ccl-program-vector ic
	  (logior (aref ccl-program-vector ic) (ash relative 8)))))

;; Embed CCL code for the operation OP and arguments REG and DATA in
;; `ccl-program-vector' at `ccl-current-ic' in the following format.
;;	|----------------- integer (28-bit) ------------------|
;;	|------------ 20-bit ------------|- 3-bit --|- 5-bit -|
;;	|------------- DATA -------------|-- REG ---|-- OP ---|
;; If REG2 is specified, embed a code in the following format.
;;	|------- 17-bit ------|- 3-bit --|- 3-bit --|- 5-bit -|
;;	|-------- DATA -------|-- REG2 --|-- REG ---|-- OP ---|

;; If REG is a CCL register symbol (e.g. r0, r1...), the register
;; number is embedded.  If OP is one of unconditional jumps, DATA is
;; changed to a relative jump address.

(defun ccl-embed-code (op reg data &optional reg2)
  (if (and (> data 0) (get op 'jump-flag))
      ;; DATA is an absolute jump address.  Make it relative to the
      ;; next of jump code.
      (setq data (- data (1+ ccl-current-ic))))
  (let ((code (logior (get op 'ccl-code)
		      (ash
		       (if (symbolp reg) (get reg 'ccl-register-number) reg) 5)
		      (if reg2
			  (logior (ash (get reg2 'ccl-register-number) 8)
				  (ash data 11))
			(ash data 8)))))
    (ccl-embed-data code)))

;; extended ccl command format
;;	|- 14-bit -|- 3-bit --|- 3-bit --|- 3-bit --|- 5-bit -|
;;	|- EX-OP --|-- REG3 --|-- REG2 --|-- REG ---|-- OP ---|
(defun ccl-embed-extended-command (ex-op reg reg2 reg3)
  (let ((data (logior (ash (get ex-op 'ccl-ex-code) 3)
		      (if (symbolp reg3)
			  (get reg3 'ccl-register-number)
			0))))
    (ccl-embed-code 'ex-cmd reg data reg2)))

;; Just advance `ccl-current-ic' by INC.
(defun ccl-increment-ic (inc)
  (setq ccl-current-ic (+ ccl-current-ic inc)))

;; If non-nil, index of the start of the current loop.
(defvar ccl-loop-head nil)
;; If non-nil, list of absolute addresses of the breaking points of
;; the current loop.
(defvar ccl-breaks nil)

;;;###autoload
(defun ccl-compile (ccl-program)
  "Return the compiled code of CCL-PROGRAM as a vector of integers."
  (if (or (null (consp ccl-program))
	  (null (integerp (car ccl-program)))
	  (null (listp (car (cdr ccl-program)))))
      (error "CCL: Invalid CCL program: %s" ccl-program))
  (if (null (vectorp ccl-program-vector))
      (setq ccl-program-vector (make-vector 8192 0)))
  (setq ccl-loop-head nil ccl-breaks nil)
  (setq ccl-current-ic 0)

  ;; The first element is the buffer magnification.
  (ccl-embed-data (car ccl-program))

  ;; The second element is the address of the start CCL code for
  ;; processing end of input buffer (we call it eof-processor).  We
  ;; set it later.
  (ccl-increment-ic 1)

  ;; Compile the main body of the CCL program.
  (ccl-compile-1 (car (cdr ccl-program)))

  ;; Embed the address of eof-processor.
  (ccl-embed-data ccl-current-ic 1)

  ;; Then compile eof-processor.
  (if (nth 2 ccl-program)
      (ccl-compile-1 (nth 2 ccl-program)))

  ;; At last, embed termination code.
  (ccl-embed-code 'end 0 0)

  (let ((vec (make-vector ccl-current-ic 0))
	(i 0))
    (while (< i ccl-current-ic)
      (aset vec i (aref ccl-program-vector i))
      (setq i (1+ i)))
    vec))

;; Signal syntax error.
(defun ccl-syntax-error (cmd)
  (error "CCL: Syntax error: %s" cmd))

;; Check if ARG is a valid CCL register.
(defun ccl-check-register (arg cmd)
  (if (get arg 'ccl-register-number)
      arg
    (error "CCL: Invalid register %s in %s" arg cmd)))

;; Check if ARG is a valid CCL command.
(defun ccl-check-compile-function (arg cmd)
  (or (get arg 'ccl-compile-function)
      (error "CCL: Invalid command: %s" cmd)))

;; In the following code, most ccl-compile-XXXX functions return t if
;; they end with unconditional jump, else return nil.

;; Compile CCL-BLOCK (see the syntax above).
(defun ccl-compile-1 (ccl-block)
  (let (unconditional-jump
	cmd)
    (if (or (integerp ccl-block)
	    (stringp ccl-block)
	    (and ccl-block (symbolp (car ccl-block))))
	;; This block consists of single statement.
	(setq ccl-block (list ccl-block)))

    ;; Now CCL-BLOCK is a list of statements.  Compile them one by
    ;; one.
    (while ccl-block
      (setq cmd (car ccl-block))
      (setq unconditional-jump
	    (cond ((integerp cmd)
		   ;; SET statement for the register 0.
		   (ccl-compile-set (list 'r0 '= cmd)))

		  ((stringp cmd)
		   ;; WRITE statement of string argument.
		   (ccl-compile-write-string cmd))

		  ((listp cmd)
		   ;; The other statements.
		   (cond ((eq (nth 1 cmd) '=)
			  ;; SET statement of the form `(REG = EXPRESSION)'.
			  (ccl-compile-set cmd))

			 ((and (symbolp (nth 1 cmd))
			       (get (nth 1 cmd) 'ccl-self-arith-code))
			  ;; SET statement with an assignment operation.
			  (ccl-compile-self-set cmd))

			 (t
			  (funcall (ccl-check-compile-function (car cmd) cmd)
				   cmd))))

		  (t
		   (ccl-syntax-error cmd))))
      (setq ccl-block (cdr ccl-block)))
    unconditional-jump))

(defconst ccl-max-short-const (ash 1 19))
(defconst ccl-min-short-const (ash -1 19))

;; Compile SET statement.
(defun ccl-compile-set (cmd)
  (let ((rrr (ccl-check-register (car cmd) cmd))
	(right (nth 2 cmd)))
    (cond ((listp right)
	   ;; CMD has the form `(RRR = (XXX OP YYY))'.
	   (ccl-compile-expression rrr right))

	  ((integerp right)
	   ;; CMD has the form `(RRR = integer)'.
	   (if (and (<= right ccl-max-short-const)
		    (>= right ccl-min-short-const))
	       (ccl-embed-code 'set-short-const rrr right)
	     (ccl-embed-code 'set-const rrr 0)
	     (ccl-embed-data right)))

	  (t
	   ;; CMD has the form `(RRR = rrr [ array ])'.
	   (ccl-check-register right cmd)
	   (let ((ary (nth 3 cmd)))
	     (if (vectorp ary)
		 (let ((i 0) (len (length ary)))
		   (ccl-embed-code 'set-array rrr len right)
		   (while (< i len)
		     (ccl-embed-data (aref ary i))
		     (setq i (1+ i))))
	       (ccl-embed-code 'set-register rrr 0 right))))))
  nil)

;; Compile SET statement with ASSIGNMENT_OPERATOR.
(defun ccl-compile-self-set (cmd)
  (let ((rrr (ccl-check-register (car cmd) cmd))
	(right (nth 2 cmd)))
    (if (listp right)
	;; CMD has the form `(RRR ASSIGN_OP (XXX OP YYY))', compile
	;; the right hand part as `(r7 = (XXX OP YYY))' (note: the
	;; register 7 can be used for storing temporary value).
	(progn
	  (ccl-compile-expression 'r7 right)
	  (setq right 'r7)))
    ;; Now CMD has the form `(RRR ASSIGN_OP ARG)'.  Compile it as
    ;; `(RRR = (RRR OP ARG))'.
    (ccl-compile-expression
     rrr
     (list rrr (intern (substring (symbol-name (nth 1 cmd)) 0 -1)) right)))
  nil)

;; Compile SET statement of the form `(RRR = EXPR)'.
(defun ccl-compile-expression (rrr expr)
  (let ((left (car expr))
	(op (get (nth 1 expr) 'ccl-arith-code))
	(right (nth 2 expr)))
    (if (listp left)
	(progn
	  ;; EXPR has the form `((EXPR2 OP2 ARG) OP RIGHT)'.  Compile
	  ;; the first term as `(r7 = (EXPR2 OP2 ARG)).'
	  (ccl-compile-expression 'r7 left)
	  (setq left 'r7)))

    ;; Now EXPR has the form (LEFT OP RIGHT).
    (if (and (eq rrr left)
	     (< op (length ccl-assign-arith-table)))
	;; Compile this SET statement as `(RRR OP= RIGHT)'.
	(if (integerp right)
	    (progn
	      (ccl-embed-code 'set-assign-expr-const rrr (ash op 3) 'r0)
	      (ccl-embed-data right))
	  (ccl-check-register right expr)
	  (ccl-embed-code 'set-assign-expr-register rrr (ash op 3) right))

      ;; Compile this SET statement as `(RRR = (LEFT OP RIGHT))'.
      (if (integerp right)
	  (progn
	    (ccl-embed-code 'set-expr-const rrr (ash op 3) left)
	    (ccl-embed-data right))
	(ccl-check-register right expr)
	(ccl-embed-code 'set-expr-register
			rrr
			(logior (ash op 3) (get right 'ccl-register-number))
			left)))))

;; Compile WRITE statement with string argument.
(defun ccl-compile-write-string (str)
  (setq str (string-as-unibyte str))
  (let ((len (length str)))
    (ccl-embed-code 'write-const-string 1 len)
    (ccl-embed-string len str))
  nil)

;; Compile IF statement of the form `(if CONDITION TRUE-PART FALSE-PART)'.
;; If READ-FLAG is non-nil, this statement has the form
;; `(read-if (REG OPERATOR ARG) TRUE-PART FALSE-PART)'.
(defun ccl-compile-if (cmd &optional read-flag)
  (if (and (/= (length cmd) 3) (/= (length cmd) 4))
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((condition (nth 1 cmd))
	(true-cmds (nth 2 cmd))
	(false-cmds (nth 3 cmd))
	jump-cond-address
	false-ic)
    (if (and (listp condition)
	     (listp (car condition)))
	;; If CONDITION is a nested expression, the inner expression
	;; should be compiled at first as SET statement, i.e.:
	;; `(if ((X OP2 Y) OP Z) ...)' is compiled into two statements:
	;; `(r7 = (X OP2 Y)) (if (r7 OP Z) ...)'.
	(progn
	  (ccl-compile-expression 'r7 (car condition))
	  (setq condition (cons 'r7 (cdr condition)))
	  (setq cmd (cons (car cmd)
			  (cons condition (cdr (cdr cmd)))))))

    (setq jump-cond-address ccl-current-ic)
    ;; Compile CONDITION.
    (if (symbolp condition)
	;; CONDITION is a register.
	(progn
	  (ccl-check-register condition cmd)
	  (ccl-embed-code 'jump-cond condition 0))
      ;; CONDITION is a simple expression of the form (RRR OP ARG).
      (let ((rrr (car condition))
	    (op (get (nth 1 condition) 'ccl-arith-code))
	    (arg (nth 2 condition)))
	(ccl-check-register rrr cmd)
	(if (integerp arg)
	    (progn
	      (ccl-embed-code (if read-flag 'read-jump-cond-expr-const
				'jump-cond-expr-const)
			      rrr 0)
	      (ccl-embed-data op)
	      (ccl-embed-data arg))
	  (ccl-check-register arg cmd)
	  (ccl-embed-code (if read-flag 'read-jump-cond-expr-register
			    'jump-cond-expr-register)
			  rrr 0)
	  (ccl-embed-data op)
	  (ccl-embed-data (get arg 'ccl-register-number)))))

    ;; Compile TRUE-PART.
    (let ((unconditional-jump (ccl-compile-1 true-cmds)))
      (if (null false-cmds)
	  ;; This is the place to jump to if condition is false.
	  (progn
	    (ccl-embed-current-address jump-cond-address)
	    (setq unconditional-jump nil))
	(let (end-true-part-address)
	  (if (not unconditional-jump)
	      (progn
		;; If TRUE-PART does not end with unconditional jump, we
		;; have to jump to the end of FALSE-PART from here.
		(setq end-true-part-address ccl-current-ic)
		(ccl-embed-code 'jump 0 0)))
	  ;; This is the place to jump to if CONDITION is false.
	  (ccl-embed-current-address jump-cond-address)
	  ;; Compile FALSE-PART.
	  (setq unconditional-jump
		(and (ccl-compile-1 false-cmds) unconditional-jump))
	  (if end-true-part-address
	      ;; This is the place to jump to after the end of TRUE-PART.
	      (ccl-embed-current-address end-true-part-address))))
      unconditional-jump)))

;; Compile BRANCH statement.
(defun ccl-compile-branch (cmd)
  (if (< (length cmd) 3)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (ccl-compile-branch-blocks 'branch
			     (ccl-compile-branch-expression (nth 1 cmd) cmd)
			     (cdr (cdr cmd))))

;; Compile READ statement of the form `(read-branch EXPR BLOCK0 BLOCK1 ...)'.
(defun ccl-compile-read-branch (cmd)
  (if (< (length cmd) 3)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (ccl-compile-branch-blocks 'read-branch
			     (ccl-compile-branch-expression (nth 1 cmd) cmd)
			     (cdr (cdr cmd))))

;; Compile EXPRESSION part of BRANCH statement and return register
;; which holds a value of the expression.
(defun ccl-compile-branch-expression (expr cmd)
  (if (listp expr)
      ;; EXPR has the form `(EXPR2 OP ARG)'.  Compile it as SET
      ;; statement of the form `(r7 = (EXPR2 OP ARG))'.
      (progn
	(ccl-compile-expression 'r7 expr)
	'r7)
    (ccl-check-register expr cmd)))

;; Compile BLOCKs of BRANCH statement.  CODE is 'branch or 'read-branch.
;; REG is a register which holds a value of EXPRESSION part.  BLOCKs
;; is a list of CCL-BLOCKs.
(defun ccl-compile-branch-blocks (code rrr blocks)
  (let ((branches (length blocks))
	branch-idx
	jump-table-head-address
	empty-block-indexes
	block-tail-addresses
	block-unconditional-jump)
    (ccl-embed-code code rrr branches)
    (setq jump-table-head-address ccl-current-ic)
    ;; The size of jump table is the number of blocks plus 1 (for the
    ;; case RRR is out of range).
    (ccl-increment-ic (1+ branches))
    (setq empty-block-indexes (list branches))
    ;; Compile each block.
    (setq branch-idx 0)
    (while blocks
      (if (null (car blocks))
	  ;; This block is empty.
	  (setq empty-block-indexes (cons branch-idx empty-block-indexes)
		block-unconditional-jump t)
	;; This block is not empty.
	(ccl-embed-data (- ccl-current-ic jump-table-head-address)
			(+ jump-table-head-address branch-idx))
	(setq block-unconditional-jump (ccl-compile-1 (car blocks)))
	(if (not block-unconditional-jump)
	    (progn
	      ;; Jump address of the end of branches are embedded later.
	      ;; For the moment, just remember where to embed them.
	      (setq block-tail-addresses
		    (cons ccl-current-ic block-tail-addresses))
	      (ccl-embed-code 'jump 0 0))))
      (setq branch-idx (1+ branch-idx))
      (setq blocks (cdr blocks)))
    (if (not block-unconditional-jump)
	;; We don't need jump code at the end of the last block.
	(setq block-tail-addresses (cdr block-tail-addresses)
	      ccl-current-ic (1- ccl-current-ic)))
    ;; Embed jump address at the tailing jump commands of blocks.
    (while block-tail-addresses
      (ccl-embed-current-address (car block-tail-addresses))
      (setq block-tail-addresses (cdr block-tail-addresses)))
    ;; For empty blocks, make entries in the jump table point directly here.
    (while empty-block-indexes
      (ccl-embed-data (- ccl-current-ic jump-table-head-address)
		      (+ jump-table-head-address (car empty-block-indexes)))
      (setq empty-block-indexes (cdr empty-block-indexes))))
  ;; Branch command ends by unconditional jump if RRR is out of range.
  nil)

;; Compile LOOP statement.
(defun ccl-compile-loop (cmd)
  (if (< (length cmd) 2)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let* ((ccl-loop-head ccl-current-ic)
	 (ccl-breaks nil)
	 unconditional-jump)
    (setq cmd (cdr cmd))
    (if cmd
	(progn
	  (setq unconditional-jump t)
	  (while cmd
	    (setq unconditional-jump
		  (and (ccl-compile-1 (car cmd)) unconditional-jump))
	    (setq cmd (cdr cmd)))
	  (if (not ccl-breaks)
	      unconditional-jump
	    ;; Embed jump address for break statements encountered in
	    ;; this loop.
	    (while ccl-breaks
	      (ccl-embed-current-address (car ccl-breaks))
	      (setq ccl-breaks (cdr ccl-breaks))))
	  nil))))

;; Compile BREAK statement.
(defun ccl-compile-break (cmd)
  (if (/= (length cmd) 1)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (if (null ccl-loop-head)
      (error "CCL: No outer loop: %s" cmd))
  (setq ccl-breaks (cons ccl-current-ic ccl-breaks))
  (ccl-embed-code 'jump 0 0)
  t)

;; Compile REPEAT statement.
(defun ccl-compile-repeat (cmd)
  (if (/= (length cmd) 1)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (if (null ccl-loop-head)
      (error "CCL: No outer loop: %s" cmd))
  (ccl-embed-code 'jump 0 ccl-loop-head)
  t)

;; Compile WRITE-REPEAT statement.
(defun ccl-compile-write-repeat (cmd)
  (if (/= (length cmd) 2)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (if (null ccl-loop-head)
      (error "CCL: No outer loop: %s" cmd))
  (let ((arg (nth 1 cmd)))
    (cond ((integerp arg)
	   (ccl-embed-code 'write-const-jump 0 ccl-loop-head)
	   (ccl-embed-data arg))
	  ((stringp arg)
	   (setq arg (string-as-unibyte arg))
	   (let ((len (length arg))
		 (i 0))
	     (ccl-embed-code 'write-string-jump 0 ccl-loop-head)
	     (ccl-embed-data len)
	     (ccl-embed-string len arg)))
	  (t
	   (ccl-check-register arg cmd)
	   (ccl-embed-code 'write-register-jump arg ccl-loop-head))))
  t)

;; Compile WRITE-READ-REPEAT statement.
(defun ccl-compile-write-read-repeat (cmd)
  (if (or (< (length cmd) 2) (> (length cmd) 3))
      (error "CCL: Invalid number of arguments: %s" cmd))
  (if (null ccl-loop-head)
      (error "CCL: No outer loop: %s" cmd))
  (let ((rrr (ccl-check-register (nth 1 cmd) cmd))
	(arg (nth 2 cmd)))
    (cond ((null arg)
	   (ccl-embed-code 'write-register-read-jump rrr ccl-loop-head))
	  ((integerp arg)
	   (ccl-embed-code 'write-const-read-jump rrr arg ccl-loop-head))
	  ((vectorp arg)
	   (let ((len (length arg))
		 (i 0))
	     (ccl-embed-code 'write-array-read-jump rrr ccl-loop-head)
	     (ccl-embed-data len)
	     (while (< i len)
	       (ccl-embed-data (aref arg i))
	       (setq i (1+ i)))))
	  (t
	   (error "CCL: Invalid argument %s: %s" arg cmd)))
    (ccl-embed-code 'read-jump rrr ccl-loop-head))
  t)

;; Compile READ statement.
(defun ccl-compile-read (cmd)
  (if (< (length cmd) 2)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let* ((args (cdr cmd))
	 (i (1- (length args))))
    (while args
      (let ((rrr (ccl-check-register (car args) cmd)))
	(ccl-embed-code 'read-register rrr i)
	(setq args (cdr args) i (1- i)))))
  nil)

;; Compile READ-IF statement.
(defun ccl-compile-read-if (cmd)
  (ccl-compile-if cmd 'read))

;; Compile WRITE statement.
(defun ccl-compile-write (cmd)
  (if (< (length cmd) 2)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((rrr (nth 1 cmd)))
    (cond ((integerp rrr)
	   (ccl-embed-code 'write-const-string 0 rrr))
	  ((stringp rrr)
	   (ccl-compile-write-string rrr))
	  ((and (symbolp rrr) (vectorp (nth 2 cmd)))
	   (ccl-check-register rrr cmd)
	   ;; CMD has the form `(write REG ARRAY)'.
	   (let* ((arg (nth 2 cmd))
		  (len (length arg))
		  (i 0))
	     (ccl-embed-code 'write-array rrr len)
	     (while (< i len)
	       (if (not (integerp (aref arg i)))
		   (error "CCL: Invalid argument %s: %s" arg cmd))
	       (ccl-embed-data (aref arg i))
	       (setq i (1+ i)))))

	  ((symbolp rrr)
	   ;; CMD has the form `(write REG ...)'.
	   (let* ((args (cdr cmd))
		  (i (1- (length args))))
	     (while args
	       (setq rrr (ccl-check-register (car args) cmd))
	       (ccl-embed-code 'write-register rrr i)
	       (setq args (cdr args) i (1- i)))))

	  ((listp rrr)
	   ;; CMD has the form `(write (LEFT OP RIGHT))'.
	   (let ((left (car rrr))
		 (op (get (nth 1 rrr) 'ccl-arith-code))
		 (right (nth 2 rrr)))
	     (if (listp left)
		 (progn
		   ;; RRR has the form `((EXPR OP2 ARG) OP RIGHT)'.
		   ;; Compile the first term as `(r7 = (EXPR OP2 ARG))'.
		   (ccl-compile-expression 'r7 left)
		   (setq left 'r7)))
	     ;; Now RRR has the form `(ARG OP RIGHT)'.
	     (if (integerp right)
		 (progn
		   (ccl-embed-code 'write-expr-const 0 (ash op 3) left)
		   (ccl-embed-data right))
	       (ccl-check-register right rrr)
	       (ccl-embed-code 'write-expr-register 0
			       (logior (ash op 3)
				       (get right 'ccl-register-number))))))

	  (t
	   (error "CCL: Invalid argument: %s" cmd))))
  nil)

;; Compile CALL statement.
(defun ccl-compile-call (cmd)
  (if (/= (length cmd) 2)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (if (not (symbolp (nth 1 cmd)))
      (error "CCL: Subroutine should be a symbol: %s" cmd))
  (ccl-embed-code 'call 1 0)
  (ccl-embed-symbol (nth 1 cmd) 'ccl-program-idx)
  nil)

;; Compile END statement.
(defun ccl-compile-end (cmd)
  (if (/= (length cmd) 1)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (ccl-embed-code 'end 0 0)
  t)

;; Compile read-multibyte-character
(defun ccl-compile-read-multibyte-character (cmd)
  (if (/= (length cmd) 3)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((RRR (nth 1 cmd))
	(rrr (nth 2 cmd)))
    (ccl-check-register rrr cmd)
    (ccl-check-register RRR cmd)
    (ccl-embed-extended-command 'read-multibyte-character rrr RRR 0))
  nil)

;; Compile write-multibyte-character
(defun ccl-compile-write-multibyte-character (cmd)
  (if (/= (length cmd) 3)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((RRR (nth 1 cmd))
	(rrr (nth 2 cmd)))
    (ccl-check-register rrr cmd)
    (ccl-check-register RRR cmd)
    (ccl-embed-extended-command 'write-multibyte-character rrr RRR 0))
  nil)

;; Compile translate-character
(defun ccl-compile-translate-character (cmd)
  (if (/= (length cmd) 4)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((Rrr (nth 1 cmd))
	(RRR (nth 2 cmd))
	(rrr (nth 3 cmd)))
    (ccl-check-register rrr cmd)
    (ccl-check-register RRR cmd)
    (cond ((and (symbolp Rrr) (not (get Rrr 'ccl-register-number)))
	   (ccl-embed-extended-command 'translate-character-const-tbl
				       rrr RRR 0)
	   (ccl-embed-symbol Rrr 'translation-table-id))
	  (t
	   (ccl-check-register Rrr cmd)
	   (ccl-embed-extended-command 'translate-character rrr RRR Rrr))))
  nil)

(defun ccl-compile-iterate-multiple-map (cmd)
  (ccl-compile-multiple-map-function 'iterate-multiple-map cmd)
  nil)

(defun ccl-compile-map-multiple (cmd)
  (if (/= (length cmd) 4)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let (func arg)
    (setq func
	  (lambda (arg mp)
	    (let ((len 0) result add)
	      (while arg
		(if (consp (car arg))
		    (setq add (funcall func (car arg) t)
			  result (append result add)
			  add (+ (- (car add)) 1))
		  (setq result
			(append result
				(list (car arg)))
			add 1))
		(setq arg (cdr arg)
		      len (+ len add)))
	      (if mp
		  (cons (- len) result)
		result))))
    (setq arg (append (list (nth 0 cmd) (nth 1 cmd) (nth 2 cmd))
		      (funcall func (nth 3 cmd) nil)))
    (ccl-compile-multiple-map-function 'map-multiple arg))
  nil)

(defun ccl-compile-map-single (cmd)
  (if (/= (length cmd) 4)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((RRR (nth 1 cmd))
	(rrr (nth 2 cmd))
	(map (nth 3 cmd))
	id)
    (ccl-check-register rrr cmd)
    (ccl-check-register RRR cmd)
    (ccl-embed-extended-command 'map-single rrr RRR 0)
    (cond ((symbolp map)
	   (if (get map 'code-conversion-map)
	       (ccl-embed-symbol map 'code-conversion-map-id)
	     (error "CCL: Invalid map: %s" map)))
	  (t
	   (error "CCL: Invalid type of arguments: %s" cmd))))
  nil)

(defun ccl-compile-multiple-map-function (command cmd)
  (if (< (length cmd) 4)
      (error "CCL: Invalid number of arguments: %s" cmd))
  (let ((RRR (nth 1 cmd))
	(rrr (nth 2 cmd))
	(args (nthcdr 3 cmd))
	map)
    (ccl-check-register rrr cmd)
    (ccl-check-register RRR cmd)
    (ccl-embed-extended-command command rrr RRR 0)
    (ccl-embed-data (length args))
    (while args
      (setq map (car args))
      (cond ((symbolp map)
	     (if (get map 'code-conversion-map)
		 (ccl-embed-symbol map 'code-conversion-map-id)
	       (error "CCL: Invalid map: %s" map)))
	    ((numberp map)
	     (ccl-embed-data map))
	    (t
	     (error "CCL: Invalid type of arguments: %s" cmd)))
      (setq args (cdr args)))))


;;; CCL dump staffs

;; To avoid byte-compiler warning.
(defvar ccl-code)

;;;###autoload
(defun ccl-dump (ccl-code)
  "Disassemble compiled CCL-CODE."
  (let ((len (length ccl-code))
	(buffer-mag (aref ccl-code 0)))
    (cond ((= buffer-mag 0)
	   (insert "Don't output anything.\n"))
	  ((= buffer-mag 1)
	   (insert "Out-buffer must be as large as in-buffer.\n"))
	  (t
	   (insert
	    (format "Out-buffer must be %d times bigger than in-buffer.\n"
		    buffer-mag))))
    (insert "Main-body:\n")
    (setq ccl-current-ic 2)
    (if (> (aref ccl-code 1) 0)
	(progn
	  (while (< ccl-current-ic (aref ccl-code 1))
	    (ccl-dump-1))
	  (insert "At EOF:\n")))
    (while (< ccl-current-ic len)
      (ccl-dump-1))
    ))

;; Return a CCL code in `ccl-code' at `ccl-current-ic'.
(defun ccl-get-next-code ()
  (prog1
      (aref ccl-code ccl-current-ic)
    (setq ccl-current-ic (1+ ccl-current-ic))))

(defun ccl-dump-1 ()
  (let* ((code (ccl-get-next-code))
	 (cmd (aref ccl-code-table (logand code 31)))
	 (rrr (ash (logand code 255) -5))
	 (cc (ash code -8)))
    (insert (format "%5d:[%s] " (1- ccl-current-ic) cmd))
    (funcall (get cmd 'ccl-dump-function) rrr cc)))

(defun ccl-dump-set-register (rrr cc)
  (insert (format "r%d = r%d\n" rrr cc)))

(defun ccl-dump-set-short-const (rrr cc)
  (insert (format "r%d = %d\n" rrr cc)))

(defun ccl-dump-set-const (rrr ignore)
  (insert (format "r%d = %d\n" rrr (ccl-get-next-code))))

(defun ccl-dump-set-array (rrr cc)
  (let ((rrr2 (logand cc 7))
	(len (ash cc -3))
	(i 0))
    (insert (format "r%d = array[r%d] of length %d\n\t"
		    rrr rrr2 len))
    (while (< i len)
      (insert (format "%d " (ccl-get-next-code)))
      (setq i (1+ i)))
    (insert "\n")))

(defun ccl-dump-jump (ignore cc &optional address)
  (insert (format "jump to %d(" (+ (or address ccl-current-ic) cc)))
  (if (>= cc 0)
      (insert "+"))
  (insert (format "%d)\n" (1+ cc))))

(defun ccl-dump-jump-cond (rrr cc)
  (insert (format "if (r%d == 0), " rrr))
  (ccl-dump-jump nil cc))

(defun ccl-dump-write-register-jump (rrr cc)
  (insert (format "write r%d, " rrr))
  (ccl-dump-jump nil cc))

(defun ccl-dump-write-register-read-jump (rrr cc)
  (insert (format "write r%d, read r%d, " rrr rrr))
  (ccl-dump-jump nil cc)
  (ccl-get-next-code)			; Skip dummy READ-JUMP
  )

(defun ccl-extract-arith-op (cc)
  (aref ccl-arith-table (ash cc -6)))

(defun ccl-dump-write-expr-const (ignore cc)
  (insert (format "write (r%d %s %d)\n"
		  (logand cc 7)
		  (ccl-extract-arith-op cc)
		  (ccl-get-next-code))))

(defun ccl-dump-write-expr-register (ignore cc)
  (insert (format "write (r%d %s r%d)\n"
		  (logand cc 7)
		  (ccl-extract-arith-op cc)
		  (logand (ash cc -3) 7))))

(defun ccl-dump-insert-char (cc)
  (cond ((= cc ?\t) (insert " \"^I\""))
	((= cc ?\n) (insert " \"^J\""))
	(t (insert (format " \"%c\"" cc)))))

(defun ccl-dump-write-const-jump (ignore cc)
  (let ((address ccl-current-ic))
    (insert "write char")
    (ccl-dump-insert-char (ccl-get-next-code))
    (insert ", ")
    (ccl-dump-jump nil cc address)))

(defun ccl-dump-write-const-read-jump (rrr cc)
  (let ((address ccl-current-ic))
    (insert "write char")
    (ccl-dump-insert-char (ccl-get-next-code))
    (insert (format ", read r%d, " rrr))
    (ccl-dump-jump cc address)
    (ccl-get-next-code)			; Skip dummy READ-JUMP
    ))

(defun ccl-dump-write-string-jump (ignore cc)
  (let ((address ccl-current-ic)
	(len (ccl-get-next-code))
	(i 0))
    (insert "write \"")
    (while (< i len)
      (let ((code (ccl-get-next-code)))
	(insert (ash code -16))
	(if (< (1+ i) len) (insert (logand (ash code -8) 255)))
	(if (< (+ i 2) len) (insert (logand code 255))))
      (setq i (+ i 3)))
    (insert "\", ")
    (ccl-dump-jump nil cc address)))

(defun ccl-dump-write-array-read-jump (rrr cc)
  (let ((address ccl-current-ic)
	(len (ccl-get-next-code))
	(i 0))
    (insert (format "write array[r%d] of length %d,\n\t" rrr len))
    (while (< i len)
      (ccl-dump-insert-char (ccl-get-next-code))
      (setq i (1+ i)))
    (insert (format "\n\tthen read r%d, " rrr))
    (ccl-dump-jump nil cc address)
    (ccl-get-next-code)			; Skip dummy READ-JUMP.
    ))

(defun ccl-dump-read-jump (rrr cc)
  (insert (format "read r%d, " rrr))
  (ccl-dump-jump nil cc))

(defun ccl-dump-branch (rrr len)
  (let ((jump-table-head ccl-current-ic)
	(i 0))
    (insert (format "jump to array[r%d] of length %d\n\t" rrr len))
    (while (<= i len)
      (insert (format "%d " (+ jump-table-head (ccl-get-next-code))))
      (setq i (1+ i)))
    (insert "\n")))

(defun ccl-dump-read-register (rrr cc)
  (insert (format "read r%d (%d remaining)\n" rrr cc)))

(defun ccl-dump-read-branch (rrr len)
  (insert (format "read r%d, " rrr))
  (ccl-dump-branch rrr len))

(defun ccl-dump-write-register (rrr cc)
  (insert (format "write r%d (%d remaining)\n" rrr cc)))

(defun ccl-dump-call (ignore cc)
  (insert (format "call subroutine #%d\n" cc)))

(defun ccl-dump-write-const-string (rrr cc)
  (if (= rrr 0)
      (progn
	(insert "write char")
	(ccl-dump-insert-char cc)
	(newline))
    (let ((len cc)
	  (i 0))
      (insert "write \"")
      (while (< i len)
	(let ((code (ccl-get-next-code)))
	  (insert (format "%c" (lsh code -16)))
	  (if (< (1+ i) len)
	      (insert (format "%c" (logand (lsh code -8) 255))))
	  (if (< (+ i 2) len)
	      (insert (format "%c" (logand code 255))))
	  (setq i (+ i 3))))
      (insert "\"\n"))))

(defun ccl-dump-write-array (rrr cc)
  (let ((i 0))
    (insert (format "write array[r%d] of length %d\n\t" rrr cc))
    (while (< i cc)
      (ccl-dump-insert-char (ccl-get-next-code))
      (setq i (1+ i)))
    (insert "\n")))

(defun ccl-dump-end (&rest ignore)
  (insert "end\n"))

(defun ccl-dump-set-assign-expr-const (rrr cc)
  (insert (format "r%d %s= %d\n"
		  rrr
		  (ccl-extract-arith-op cc)
		  (ccl-get-next-code))))

(defun ccl-dump-set-assign-expr-register (rrr cc)
  (insert (format "r%d %s= r%d\n"
		  rrr
		  (ccl-extract-arith-op cc)
		  (logand cc 7))))

(defun ccl-dump-set-expr-const (rrr cc)
  (insert (format "r%d = r%d %s %d\n"
		  rrr
		  (logand cc 7)
		  (ccl-extract-arith-op cc)
		  (ccl-get-next-code))))

(defun ccl-dump-set-expr-register (rrr cc)
  (insert (format "r%d = r%d %s r%d\n"
		  rrr
		  (logand cc 7)
		  (ccl-extract-arith-op cc)
		  (logand (ash cc -3) 7))))

(defun ccl-dump-jump-cond-expr-const (rrr cc)
  (let ((address ccl-current-ic))
    (insert (format "if !(r%d %s %d), "
		    rrr
		    (aref ccl-arith-table (ccl-get-next-code))
		    (ccl-get-next-code)))
    (ccl-dump-jump nil cc address)))

(defun ccl-dump-jump-cond-expr-register (rrr cc)
  (let ((address ccl-current-ic))
    (insert (format "if !(r%d %s r%d), "
		    rrr
		    (aref ccl-arith-table (ccl-get-next-code))
		    (ccl-get-next-code)))
    (ccl-dump-jump nil cc address)))

(defun ccl-dump-read-jump-cond-expr-const (rrr cc)
  (insert (format "read r%d, " rrr))
  (ccl-dump-jump-cond-expr-const rrr cc))

(defun ccl-dump-read-jump-cond-expr-register (rrr cc)
  (insert (format "read r%d, " rrr))
  (ccl-dump-jump-cond-expr-register rrr cc))

(defun ccl-dump-binary (ccl-code)
  (let ((len (length ccl-code))
	(i 2))
    (while (< i len)
      (let ((code (aref ccl-code i))
	    (j 27))
	(while (>= j 0)
	  (insert (if (= (logand code (ash 1 j)) 0) ?0 ?1))
	  (setq j (1- j)))
	(setq code (logand code 31))
	(if (< code (length ccl-code-table))
	    (insert (format ":%s" (aref ccl-code-table code))))
	(insert "\n"))
      (setq i (1+ i)))))

(defun ccl-dump-ex-cmd (rrr cc)
  (let* ((RRR (logand cc ?\x7))
	 (Rrr (logand (ash cc -3) ?\x7))
	 (ex-op (aref ccl-extended-code-table (logand (ash cc -6) ?\x3fff))))
    (insert (format "<%s> " ex-op))
    (funcall (get ex-op 'ccl-dump-function) rrr RRR Rrr)))

(defun ccl-dump-read-multibyte-character (rrr RRR Rrr)
  (insert (format "read-multibyte-character r%d r%d\n" RRR rrr)))

(defun ccl-dump-write-multibyte-character (rrr RRR Rrr)
  (insert (format "write-multibyte-character r%d r%d\n" RRR rrr)))

(defun ccl-dump-translate-character (rrr RRR Rrr)
  (insert (format "translation table(r%d) r%d r%d\n" Rrr RRR rrr)))

(defun ccl-dump-translate-character-const-tbl (rrr RRR Rrr)
  (let ((tbl (ccl-get-next-code)))
    (insert (format "translation table(%S) r%d r%d\n" tbl RRR rrr))))

(defun ccl-dump-iterate-multiple-map (rrr RRR Rrr)
  (let ((notbl (ccl-get-next-code))
	(i 0) id)
    (insert (format "iterate-multiple-map r%d r%d\n" RRR rrr))
    (insert (format "\tnumber of maps is %d .\n\t [" notbl))
    (while (< i notbl)
      (setq id (ccl-get-next-code))
      (insert (format "%S" id))
      (setq i (1+ i)))
    (insert "]\n")))

(defun ccl-dump-map-multiple (rrr RRR Rrr)
  (let ((notbl (ccl-get-next-code))
	(i 0) id)
    (insert (format "map-multiple r%d r%d\n" RRR rrr))
    (insert (format "\tnumber of maps and separators is %d\n\t [" notbl))
    (while (< i notbl)
      (setq id (ccl-get-next-code))
      (if (= id -1)
	  (insert "]\n\t [")
	(insert (format "%S " id)))
      (setq i (1+ i)))
    (insert "]\n")))

(defun ccl-dump-map-single (rrr RRR Rrr)
  (let ((id (ccl-get-next-code)))
    (insert (format "map-single r%d r%d map(%S)\n" RRR rrr id))))


;; CCL emulation staffs

;; Not yet implemented.

;; Auto-loaded functions.

;;;###autoload
(defmacro declare-ccl-program (name &optional vector)
  "Declare NAME as a name of CCL program.

This macro exists for backward compatibility.  In the old version of
Emacs, to compile a CCL program which calls another CCL program not
yet defined, it must be declared as a CCL program in advance.  But,
now CCL program names are resolved not at compile time but before
execution.

Optional arg VECTOR is a compiled CCL code of the CCL program."
  `(put ',name 'ccl-program-idx (register-ccl-program ',name ,vector)))

;;;###autoload
(defmacro define-ccl-program (name ccl-program &optional doc)
  "Set NAME the compiled code of CCL-PROGRAM.

CCL-PROGRAM has this form:
	(BUFFER_MAGNIFICATION
	 CCL_MAIN_CODE
	 [ CCL_EOF_CODE ])

BUFFER_MAGNIFICATION is an integer value specifying the approximate
output buffer magnification size compared with the bytes of input data
text.  If the value is zero, the CCL program can't execute `read' and
`write' commands.

CCL_MAIN_CODE and CCL_EOF_CODE are CCL program codes.  CCL_MAIN_CODE
executed at first.  If there's no more input data when `read' command
is executed in CCL_MAIN_CODE, CCL_EOF_CODE is executed.  If
CCL_MAIN_CODE is terminated, CCL_EOF_CODE is not executed.

Here's the syntax of CCL program code in BNF notation.  The lines
starting by two semicolons (and optional leading spaces) describe the
semantics.

CCL_MAIN_CODE := CCL_BLOCK

CCL_EOF_CODE := CCL_BLOCK

CCL_BLOCK := STATEMENT | (STATEMENT [STATEMENT ...])

STATEMENT :=
	SET | IF | BRANCH | LOOP | REPEAT | BREAK | READ | WRITE | CALL
	| TRANSLATE | END

SET :=	(REG = EXPRESSION)
	| (REG ASSIGNMENT_OPERATOR EXPRESSION)
	;; The following form is the same as (r0 = integer).
	| integer

EXPRESSION := ARG | (EXPRESSION OPERATOR ARG)

;; Evaluate EXPRESSION.  If the result is nonzero, execute
;; CCL_BLOCK_0.  Otherwise, execute CCL_BLOCK_1.
IF :=	(if EXPRESSION CCL_BLOCK_0 CCL_BLOCK_1)

;; Evaluate EXPRESSION.  Provided that the result is N, execute
;; CCL_BLOCK_N.
BRANCH := (branch EXPRESSION CCL_BLOCK_0 [CCL_BLOCK_1 ...])

;; Execute STATEMENTs until (break) or (end) is executed.
LOOP := (loop STATEMENT [STATEMENT ...])

;; Terminate the most inner loop.
BREAK := (break)

REPEAT :=
	;; Jump to the head of the most inner loop.
	(repeat)
	;; Same as: ((write [REG | integer | string])
	;;	     (repeat))
	| (write-repeat [REG | integer | string])
	;; Same as: ((write REG [ARRAY])
	;;	     (read REG)
	;;	     (repeat))
	| (write-read-repeat REG [ARRAY])
	;; Same as: ((write integer)
	;;	     (read REG)
	;;	     (repeat))
	| (write-read-repeat REG integer)

READ := ;; Set REG_0 to a byte read from the input text, set REG_1
	;; to the next byte read, and so on.
	(read REG_0 [REG_1 ...])
	;; Same as: ((read REG)
	;;	     (if (REG OPERATOR ARG) CCL_BLOCK_0 CCL_BLOCK_1))
	| (read-if (REG OPERATOR ARG) CCL_BLOCK_0 CCL_BLOCK_1)
	;; Same as: ((read REG)
	;;	     (branch REG CCL_BLOCK_0 [CCL_BLOCK_1 ...]))
	| (read-branch REG CCL_BLOCK_0 [CCL_BLOCK_1 ...])
	;; Read a character from the input text while parsing
	;; multibyte representation, set REG_0 to the charset ID of
	;; the character, set REG_1 to the code point of the
	;; character.  If the dimension of charset is two, set REG_1
	;; to ((CODE0 << 7) | CODE1), where CODE0 is the first code
	;; point and CODE1 is the second code point.
	| (read-multibyte-character REG_0 REG_1)

WRITE :=
	;; Write REG_0, REG_1, ... to the output buffer.  If REG_N is
	;; a multibyte character, write the corresponding multibyte
	;; representation.
	(write REG_0 [REG_1 ...])
	;; Same as: ((r7 = EXPRESSION)
	;;	     (write r7))
	| (write EXPRESSION)
	;; Write the value of `integer' to the output buffer.  If it
	;; is a multibyte character, write the corresponding multibyte
	;; representation.
	| (write integer)
	;; Write the byte sequence of `string' as is to the output
	;; buffer.
	| (write string)
	;; Same as: (write string)
	| string
	;; Provided that the value of REG is N, write Nth element of
	;; ARRAY to the output buffer.  If it is a multibyte
	;; character, write the corresponding multibyte
	;; representation.
	| (write REG ARRAY)
	;; Write a multibyte representation of a character whose
	;; charset ID is REG_0 and code point is REG_1.  If the
	;; dimension of the charset is two, REG_1 should be ((CODE0 <<
	;; 7) | CODE1), where CODE0 is the first code point and CODE1
	;; is the second code point of the character.
	| (write-multibyte-character REG_0 REG_1)

;; Call CCL program whose name is ccl-program-name.
CALL := (call ccl-program-name)

;; Terminate the CCL program.
END := (end)

;; CCL registers that can contain any integer value.  As r7 is also
;; used by CCL interpreter, its value is changed unexpectedly.
REG := r0 | r1 | r2 | r3 | r4 | r5 | r6 | r7

ARG := REG | integer

OPERATOR :=
	;; Normal arithmethic operators (same meaning as C code).
	+ | - | * | / | %

	;; Bitwize operators (same meaning as C code)
	| & | `|' | ^

	;; Shifting operators (same meaning as C code)
	| << | >>

	;; (REG = ARG_0 <8 ARG_1) means:
	;;	(REG = ((ARG_0 << 8) | ARG_1))
	| <8

	;; (REG = ARG_0 >8 ARG_1) means:
	;;	((REG = (ARG_0 >> 8))
	;;	 (r7 = (ARG_0 & 255)))
	| >8

	;; (REG = ARG_0 // ARG_1) means:
	;;	((REG = (ARG_0 / ARG_1))
	;;	 (r7 = (ARG_0 % ARG_1)))
	| //

	;; Normal comparing operators (same meaning as C code)
	| < | > | == | <= | >= | !=

	;; If ARG_0 and ARG_1 are higher and lower byte of Shift-JIS
	;; code, and CHAR is the corresponding JISX0208 character,
	;; (REG = ARG_0 de-sjis ARG_1) means:
	;;	((REG = CODE0)
	;;	 (r7 = CODE1))
	;; where CODE0 is the first code point of CHAR, CODE1 is the
	;; second code point of CHAR.
	| de-sjis

	;; If ARG_0 and ARG_1 are the first and second code point of
	;; JISX0208 character CHAR, and SJIS is the correponding
	;; Shift-JIS code,
	;; (REG = ARG_0 en-sjis ARG_1) means:
	;;	((REG = HIGH)
	;;	 (r7 = LOW))
	;; where HIGH is the higher byte of SJIS, LOW is the lower
	;; byte of SJIS.
	| en-sjis

ASSIGNMENT_OPERATOR :=
	;; Same meaning as C code
	+= | -= | *= | /= | %= | &= | `|=' | ^= | <<= | >>=

	;; (REG <8= ARG) is the same as:
	;;	((REG <<= 8)
	;;	 (REG |= ARG))
	| <8=

	;; (REG >8= ARG) is the same as:
	;;	((r7 = (REG & 255))
	;;	 (REG >>= 8))

	;; (REG //= ARG) is the same as:
	;;	((r7 = (REG % ARG))
	;;	 (REG /= ARG))
	| //=

ARRAY := `[' integer ... `]'


TRANSLATE :=
	(translate-character REG(table) REG(charset) REG(codepoint))
	| (translate-character SYMBOL REG(charset) REG(codepoint))
        ;; SYMBOL must refer to a table defined by `define-translation-table'.
MAP :=
     (iterate-multiple-map REG REG MAP-IDs)
     | (map-multiple REG REG (MAP-SET))
     | (map-single REG REG MAP-ID)
MAP-IDs := MAP-ID ...
MAP-SET := MAP-IDs | (MAP-IDs) MAP-SET
MAP-ID := integer
"
  `(let ((prog ,(ccl-compile (eval ccl-program))))
     (defconst ,name prog ,doc)
     (put ',name 'ccl-program-idx (register-ccl-program ',name prog))
     nil))

;;;###autoload
(defmacro check-ccl-program (ccl-program &optional name)
  "Check validity of CCL-PROGRAM.
If CCL-PROGRAM is a symbol denoting a CCL program, return
CCL-PROGRAM, else return nil.
If CCL-PROGRAM is a vector and optional arg NAME (symbol) is supplied,
register CCL-PROGRAM by name NAME, and return NAME."
  `(if (ccl-program-p ,ccl-program)
       (if (vectorp ,ccl-program)
	   (progn
	     (register-ccl-program ,name ,ccl-program)
	     ,name)
	 ,ccl-program)))

;;;###autoload
(defun ccl-execute-with-args (ccl-prog &rest args)
  "Execute CCL-PROGRAM with registers initialized by the remaining args.
The return value is a vector of resulting CCL registers.

See the documentation of `define-ccl-program' for the detail of CCL program."
  (let ((reg (make-vector 8 0))
	(i 0))
    (while (and args (< i 8))
      (if (not (integerp (car args)))
	  (error "Arguments should be integer"))
      (aset reg i (car args))
      (setq args (cdr args) i (1+ i)))
    (ccl-execute ccl-prog reg)
    reg))

(provide 'ccl)

;;; ccl.el ends here
