/* lx4dec.f -- translated by f2c (version 19980913).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* $Procedure      LX4DEC (Scan for signed integer) */
/* Subroutine */ int lx4dec_(char *string, integer *first, integer *last, 
	integer *nchar, ftnlen string_len)
{
    /* Builtin functions */
    integer i_len(char *, ftnlen);

    /* Local variables */
    integer next, f, i__, j, l, n;
    extern /* Subroutine */ int lx4sgn_(char *, integer *, integer *, integer 
	    *, ftnlen), lx4uns_(char *, integer *, integer *, integer *, 
	    ftnlen);

/* $ Abstract */

/*     Scan a string from a specified starting position for the */
/*     end of a decimal number. */


/* $ Disclaimer */

/*     THIS SOFTWARE AND ANY RELATED MATERIALS WERE CREATED BY THE */
/*     CALIFORNIA INSTITUTE OF TECHNOLOGY (CALTECH) UNDER A U.S. */
/*     GOVERNMENT CONTRACT WITH THE NATIONAL AERONAUTICS AND SPACE */
/*     ADMINISTRATION (NASA). THE SOFTWARE IS TECHNOLOGY AND SOFTWARE */
/*     PUBLICLY AVAILABLE UNDER U.S. EXPORT LAWS AND IS PROVIDED "AS-IS" */
/*     TO THE RECIPIENT WITHOUT WARRANTY OF ANY KIND, INCLUDING ANY */
/*     WARRANTIES OF PERFORMANCE OR MERCHANTABILITY OR FITNESS FOR A */
/*     PARTICULAR USE OR PURPOSE (AS SET FORTH IN UNITED STATES UCC */
/*     SECTIONS 2312-2313) OR FOR ANY PURPOSE WHATSOEVER, FOR THE */
/*     SOFTWARE AND RELATED MATERIALS, HOWEVER USED. */

/*     IN NO EVENT SHALL CALTECH, ITS JET PROPULSION LABORATORY, OR NASA */
/*     BE LIABLE FOR ANY DAMAGES AND/OR COSTS, INCLUDING, BUT NOT */
/*     LIMITED TO, INCIDENTAL OR CONSEQUENTIAL DAMAGES OF ANY KIND, */
/*     INCLUDING ECONOMIC DAMAGE OR INJURY TO PROPERTY AND LOST PROFITS, */
/*     REGARDLESS OF WHETHER CALTECH, JPL, OR NASA BE ADVISED, HAVE */
/*     REASON TO KNOW, OR, IN FACT, SHALL KNOW OF THE POSSIBILITY. */

/*     RECIPIENT BEARS ALL RISK RELATING TO QUALITY AND PERFORMANCE OF */
/*     THE SOFTWARE AND ANY RELATED MATERIALS, AND AGREES TO INDEMNIFY */
/*     CALTECH AND NASA FOR ALL THIRD-PARTY CLAIMS RESULTING FROM THE */
/*     ACTIONS OF RECIPIENT IN THE USE OF THE SOFTWARE. */

/* $ Required_Reading */

/*      None. */

/* $ Keywords */

/*       PARSING */

/* $ Declarations */
/* $ Brief_I/O */

/*      VARIABLE  I/O  DESCRIPTION */
/*      --------  ---  -------------------------------------------------- */
/*      STRING     I   any character string */
/*      FIRST      I   first character to scan from in STRING */
/*      LAST       O   last character that is part of a decimal number */
/*      NCHAR      O   number of characters in the decimal number. */

/* $ Detailed_Input */

/*     STRING      is any character string. */

/*     FIRST       is the location in the string to beginning scanning */
/*                 for a decimal number.  It is assumed that the */
/*                 decimal number begins at FIRST. */

/* $ Detailed_Output */

/*     LAST        is the last character at or after FIRST such that */
/*                 the substring STRING(FIRST:LAST) is a decimal */
/*                 number.  If there is no such substring, LAST */
/*                 will be returned with the value FIRST-1. */

/*     NCHAR       is the number of characters in the decimal number */
/*                 that begins at FIRST and ends at last.  If there */
/*                 is no such string NCHAR will be given the value 0. */

/* $ Parameters */

/*      None. */

/* $ Files */

/*      None. */

/* $ Exceptions */

/*     Error free. */

/*     1) If FIRST is beyond either end of the string, then */
/*        LAST will be returned with the value FIRST and NCHAR */
/*        will be returned with the value 0. */

/*     2) If STRING(FIRST:FIRST) is not part of a decimal number */
/*        then LAST will be returned with the value FIRST-1 and NCHAR */
/*        will be returned with the value 0. */

/* $ Particulars */

/*     This routine allows you to scan forward in a string to locate */
/*     a decimal number that begins on the input character FIRST.  Note */
/*     that all signed integers are included in the list of decimal */
/*     numbers.  See LX4SGN for a description of signed integers. */

/*     We let S stand for a signed integer and U stand for */
/*     an unsigned integer.  With this notation, the strings */
/*     recognized as decimal numbers are: */

/*        U */
/*        S */
/*        S. */
/*        S.U */
/*         .U */
/*        -.U */
/*        +.U */


/* $ Examples */

/*     Suppose you believe that a string has the form */

/*        X%Y%Z */

/*     where X, Y, and Z are decimal numbers of some unknown */
/*     length and % stands for some non-digit character. You could */
/*     use this routine to locate the decimal numbers in the */
/*     string as shown below.  We'll keep track of the beginning and */
/*     ending of the decimal numbers in the integer arrays B and E. */

/*     FIRST = 1 */
/*     I     = 0 */

/*     DO WHILE ( FIRST .LT. LEN(STRING) ) */

/*        CALL LX4DEC ( STRING, FIRST, LAST, NCHAR ) */

/*        IF ( NCHAR .GT. 0 ) THEN */

/*           I     = I    + 1 */
/*           B(I)  = FIRST */
/*           E(I)  = LAST */
/*           FIRST = LAST + 2 */

/*        ELSE */

/*           FIRST = FIRST + 1 */

/*        END IF */

/*     END DO */


/* $ Restrictions */

/*     None. */

/* $ Author_and_Institution */

/*      W.L. Taber      (JPL) */

/* $ Literature_References */

/*      None. */

/* $ Version */

/* -    SPICELIB Version 1.1.0, 28-NOV-1995 (WLT) */

/*        Upgraded the routine to handle strings of the form */
/*        '+.01' and '-.01' which were regarded as non-decimal */
/*        strings before. */

/* -    SPICELIB Version 1.0.0, 12-JUL-1994 (WLT) */


/* -& */
/* $ Index_Entries */

/*     Scan a string for a signed integer. */

/* -& */
    *last = *first - 1;
    next = *first + 1;
    l = i_len(string, string_len);

/*     If start is beyond the ends of the string, we  can quit now. */

    if (*first < 1 || *first > l) {
	*nchar = 0;
	return 0;
    }

/*     There are two cases to take care of (and in both cases */
/*     LX4SGN or LX4UNS do  almost all of the work). */

    i__ = *(unsigned char *)&string[*first - 1];
    if (next < l) {
	j = *(unsigned char *)&string[next - 1];
    } else {
	j = ' ';
    }
    if (i__ == '.') {

/*        Case 1. The string begins with a decimal point. */
/*        There must be an unsigned integer following. */

	f = *first + 1;
	lx4uns_(string, &f, last, nchar, string_len);
	if (*nchar == 0) {
	    *last = *first - 1;
	} else {
	    ++(*nchar);
	}
    } else if ((i__ == '-' || i__ == '+') && j == '.') {

/*        Case 2. The string begins with a sign followed by */
/*        a decimal point. There must be an unsigned integer following. */

	f = next + 1;
	lx4uns_(string, &f, last, nchar, string_len);
	if (*nchar == 0) {
	    *last = *first - 1;
	} else {
	    ++(*nchar);
	}
    } else if (i__ == '+' && j == '.') {

/*        Case 2. The string begins with a minus sign followed by */
/*        a decimal point. There must be an unsigned integer following. */

	f = next + 1;
	lx4uns_(string, &f, last, nchar, string_len);
	if (*nchar == 0) {
	    *last = *first - 1;
	} else {
	    ++(*nchar);
	}
    } else {

/*        Case 3.  The leading character is not a decimal point. */
/*        First check to see how much signed integer we have. */

	lx4sgn_(string, first, last, nchar, string_len);

/*        If we got some part of a signed integer, we next see */
/*        if there is a decimal point followed by an unsigned */
/*        integer. */

	if (*nchar > 0 && *last < l) {
	    f = *last + 1;
	    i__ = *(unsigned char *)&string[f - 1];
	    if (i__ == '.') {
		*last = f;
		f = *last + 1;

/*              After the decimal point we may have an unsigned integer. */

		lx4uns_(string, &f, last, &n, string_len);

/*              LAST is either pointing to the decimal point or the */
/*              end of an unsigned integer.  In either case we need */
/*              to update NCHAR. */

		*nchar = *last + 1 - *first;
	    }
	}
    }
    return 0;
} /* lx4dec_ */

