X-Git-Url: https://ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=ginac%2Fparser%2Flexer.cpp;h=abbe75162bae4fc614ca6aa8bd87cfe205b22353;hb=1109fafaa3f5da6d1483744c4bdee6f01a37c5c5;hp=1cc2f49671d20023edb9c31e150ad03628479a3e;hpb=cd6f949add6caf2f0cc52731e34252aea9c9ad2d;p=ginac.git

diff --git a/ginac/parser/lexer.cpp b/ginac/parser/lexer.cpp
index 1cc2f496..abbe7516 100644
--- a/ginac/parser/lexer.cpp
+++ b/ginac/parser/lexer.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's lexer. */
 
 /*
- *  GiNaC Copyright (C) 1999-2009 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2018 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -43,12 +43,12 @@ int lexer::gettok()
 	// Skip any whitespace.
 	c = skipspace(input, c, line_num);
 
-	// identifier: [a-zA-Z][a-zA-Z0-9]*
+	// identifier: [a-zA-Z][a-zA-Z0-9_]*
 	if (isalpha(c)) { 
 		str = c;
 		do {
 			c = input->get();
-			if (isalnum(c))
+			if ( isalnum(c) || c=='_' )
 				str += c;
 			else
 				break;