NAME: NEXTTOK PURPOSE: Find the next occurance of any of a set of characters in a string and return the character which occurs next. CATEGORY: text/strings CALLING SEQUENCE: tok = nexttok( strn, tokens ) INPUTS: strn -- string to be searched for sub/superscripts in tokens -- string containing characters to be found. in KEYWORD PARAMETERS: POSITION -- Set to a named variable to get position out of next token, or -1 if none found. /HELP -- Print useful message and exit. OUTPUTS: tok -- Contains the character among tokens which out occurs next in strn, or null '' if none found. COMMON BLOCKS: SIDE EFFECTS: NOTES: EXAMPLE: nexttok( 'x^2 + N_j^3', '^_', position=pos ) returns '^' and sets pos to 1. MODIFICATION HISTORY: $Id: nexttok.pro 114 2006-06-19 14:14:56Z smasson $ $Log: nexttok.pro,v $ Revision 1.4 2004/06/15 17:25:54 mcraig Fixed bug in regular expression, changed array notation to square brackets Revision 1.3 1996/06/14 20:00:27 mcraig Updated Copyright info. Revision 1.2 1996/05/09 00:22:17 mcraig Generalized so that the next occurence of any of a set of characters will be returned. Revision 1.1 1996/01/31 18:41:06 mcraig Initial revision RELEASE: $Name: Rel_2_1_2 $ COPYRIGHT: Copyright (C) 1996 The Regents of the University of California, All Rights Reserved. Written by Matthew W. Craig. See the file COPYRIGHT for restrictions on distrubting this code. This code comes with absolutely NO warranty; see DISCLAIMER for details.