*	'double' and 'mp_int' types.
 *
 * Copyright (c) 2005 by Kevin B. Kenny.  All rights reserved.
 *
 * See the file "license.terms" for information on usage and redistribution of
 * this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclStrToD.c,v 1.4.2.8 2005/12/02 18:42:08 dgp Exp $
 * RCS: @(#) $Id: tclStrToD.c,v 1.4.2.9 2006/01/25 18:38:31 dgp Exp $
 *
 *----------------------------------------------------------------------
 */

#include <tclInt.h>
#include <stdio.h>
#include <stdlib.h>

 *	negative, the first NUL byte encountered will terminate the scan.
 *	If numBytes is non-negative, then no more than numBytes bytes will
 *	be scanned.  
 *
 *	The argument flags is an input that controls the numeric formats
 *	recognized by the parser.  The flag bits are:
 *
 *	 - TCL_PARSE_INTEGER_ONLY:	accept only integer values; reject
 *	- TCL_PARSE_INTEGER_ONLY:	accept only integer values; reject
 *		strings that denote floating point values (or accept only the
 *		leading portion of them that are integer values).
 *	- TCL_PARSE_SCAN_PREFIXES:	ignore the prefixes 0b and 0o that are
 *		not part of the [scan] command's vocabulary. Use only in
 *		combination with TCL_PARSE_INTEGER_ONLY.
 * 	- TCL_PARSE_OCTAL_ONLY:		parse only in the octal format, whether
 *		or not a prefix is present that would lead to octal parsing. Use
 *		only in combination with TCL_PARSE_INTEGER_ONLY.
 * 	- TCL_PARSE_HEXADECIMAL_ONLY:	parse only in the hexadecimal format,
 *		whether or not a prefix is present that would lead to
 *		hexadecimal parsing. Use only in combination with
 *		TCL_PARSE_INTEGER_ONLY.
 * 	- TCL_PARSE_DECIMAL_ONLY:	parse only in the decimal format, no
 *		matter whether a 0 prefix would normally force a different base.
 *	- TCL_PARSE_NO_WHITESPACE:	reject any leading/trailing whitespace
 *
 *	The arguments interp and expected are inputs that control error message
 * 	generation.  If interp is NULL, no error message will be generated.
 *	If interp is non-NULL, then expected must also be non-NULL.  When
 *	TCL_ERROR is returned, an error message will be left in the result
 *	of interp, and the expected argument will appear in the error message
 *	as the thing TclParseNumber expected, but failed to find in the string.

 *	then the internal rep and Tcl_ObjType of objPtr are set	to the
 *	"canonical" numeric value that matches the scanned string.  If
 *	endPtrPtr is non-NULL, a pointer to the end of the string will be
 *	written to *endPtrPtr (that is, either bytes+numBytes or a pointer
 *	to a terminating NUL byte).
 *
 *	When the parser determines that a partial string matches a format
 *	it is looking for, the value of endPtrPtr determines what happens.
 *	it is looking for, the value of endPtrPtr determines what happens:
 *
 *	If endPtrPtr is NULL, then the remainder of the string is scanned
 *	and if it consists entirely of trailing whitespace, then TCL_OK is
 *	returned and objPtr internals are set as above.  If any non-whitespace
 *	is encountered, TCL_ERROR is returned, with error message generation
 *	as above.
 *	- If endPtrPtr is NULL, then TCL_ERROR is returned, with error message
 *		generation as above.
 *
 *	When the parser detects a partial string match and endPtrPtr is
 *	non-NULL, then TCL_OK is returned and objPtr internals are set as
 *	above.  Also, a pointer to the first character following the parsed
 *	numeric string is written to *endPtrPtr.
 *	- If endPtrPtr is non-NULL, then TCL_OK is returned and objPtr
 *		internals are set as above.  Also, a pointer to the first
 *		character following the parsed numeric string is written
 *		to *endPtrPtr.
 *
 *	In some cases where the string being scanned is the string rep of
 *	objPtr, this routine can leave objPtr in an inconsistent state
 *	where its string rep and its internal rep do not agree.  In these
 *	cases the internal rep will be in agreement with only some substring
 *	of the string rep.  This might happen if the caller passes in a
 * 	non-NULL bytes value that points somewhere into the string rep.  It

	case INITIAL:
	    /*
	     * Initial state. Acceptable characters are +, -, digits, period,
	     * I, N, and whitespace.
	     */

	    if (isspace(UCHAR(c))) {
		if (flags & TCL_PARSE_NO_WHITESPACE) {
		    goto endgame;
		}
		break;
	    } else if (c == '+') {
		state = SIGNUM;
		break;
	    } else if (c == '-') {
		signum = 1;
		state = SIGNUM;

	if (endPtrPtr != NULL) {
	    *endPtrPtr = p;
	}
    } else {
	/* Back up to the last accepting state in the lexer. */
	p = acceptPoint;
	len = acceptLen;
	if (endPtrPtr == NULL) {
	if (!(flags & TCL_PARSE_NO_WHITESPACE)) {
	    /* Accept trailing whitespace */
	    while (len != 0 && isspace(UCHAR(*p))) {
		++p;
		--len;
	    }
	}
	if (endPtrPtr == NULL) {
	    if ((len != 0) && ((numBytes > 0) || (*p != '\0'))) {
		status = TCL_ERROR;
	    }
	} else {
	    *endPtrPtr = p;
	}
    }

	mp_clear(pow5 + i);
    }
}

/*
 *----------------------------------------------------------------------
 *
 * TclInitBignumFromDouble --
 * Tcl_InitBignumFromDouble --
 *
 *	Extracts the integer part of a double and converts it to an arbitrary
 *	precision integer.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Initializes the bignum supplied, and stores the converted number * in
 *	it.
 *	Initializes the bignum supplied, and stores the converted number 
 *      in it.
 *
 *----------------------------------------------------------------------
 */

int
TclInitBignumFromDouble(
Tcl_InitBignumFromDouble(
    Tcl_Interp *interp,		/* For error message */
    double d,			/* Number to convert */
    mp_int *b)			/* Place to store the result */
{
    double fract;
    int expt;