*	'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 1.27 2007/02/20 23:24:03 nijtmans Exp $
 *
 *----------------------------------------------------------------------
 */

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

static double tiny;		/* The smallest representable double */
static int maxDigits;		/* The maximum number of digits to the left of
				 * the decimal point of a double. */
static int minDigits;		/* The maximum number of digits to the right
				 * of the decimal point in a double. */
static int mantDIGIT;		/* Number of mp_digit's needed to hold the
				 * significand of a double. */
static const double pow_10_2_n[] = {	/* Inexact higher powers of ten. */
    1.0,
    100.0,
    10000.0,
    1.0e+8,
    1.0e+16,
    1.0e+32,
    1.0e+64,

 *----------------------------------------------------------------------
 */

int
TclParseNumber(
    Tcl_Interp *interp,		/* Used for error reporting. May be NULL */
    Tcl_Obj *objPtr,		/* Object to receive the internal rep */
    const char *expected,	/* Description of the type of number the caller
				 * expects to be able to parse ("integer", 
				 * "boolean value", etc.). */
    const char *bytes,		/* Pointer to the start of the string to scan */
    int numBytes,		/* Maximum number of bytes to scan, see above */
    const char **endPtrPtr,	/* Place to store pointer to the character
				 * that terminated the scan */
    int flags)			/* Flags governing the parse */
{
    enum State {
	INITIAL, SIGNUM, ZERO, ZERO_X, 
	ZERO_O, ZERO_B, BINARY,
	HEXADECIMAL, OCTAL, BAD_OCTAL, DECIMAL, 

    int numTrailZeros = 0;	/* Number of trailing zeroes at the current
				 * point in the parse. */
    int numDigitsAfterDp = 0;	/* Number of digits scanned after the decimal
				 * point */
    int exponentSignum = 0;	/* Signum of the exponent of a floating point
				 * number */
    long exponent = 0;		/* Exponent of a floating point number */
    const char *p;		/* Pointer to next character to scan */
    size_t len;			/* Number of characters remaining after p */
    const char *acceptPoint;	/* Pointer to position after last character in
				 * an acceptable number */
    size_t acceptLen;		/* Number of characters following that
				 * point. */
    int status = TCL_OK;	/* Status to return to caller */
    char d = 0;			/* Last hexadecimal digit scanned; initialized
				 * to avoid a compiler warning. */
    int shift = 0;		/* Amount to shift when accumulating binary */

    /*
     * Infinite values can't convert to bignum.
     */

    if (TclIsInfinite(d)) {
	if (interp != NULL) {
	    const char *s = "integer value too large to represent";
	    Tcl_SetObjResult(interp, Tcl_NewStringObj(s, -1));
	    Tcl_SetErrorCode(interp, "ARITH", "IOVERFLOW", s, NULL);
	}
	return TCL_ERROR;
    }

    fract = frexp(d,&expt);