X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?a=blobdiff_plain;f=ginac%2Fparser%2Flexer.cpp;h=437db17542ca6175e5c68ca42780f4bfe6e453b6;hb=866b3eb23253a272788d8791b1ed023e63674d50;hp=050c85f73454a865750932297b0d0885a1bb934f;hpb=1602530f716ba1d425a0667b897182b99c374823;p=ginac.git

diff --git a/ginac/parser/lexer.cpp b/ginac/parser/lexer.cpp
index 050c85f7..437db175 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) 1999-2010 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
@@ -26,6 +26,7 @@
 #include <iostream>
 #include <sstream>
 #include <string>
+#include <cstdio>
 
 namespace GiNaC {
 
@@ -42,12 +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;