Parser: handle abbreviations as advertized in the manual.

[ginac.git] / ginac / parser / parse_context.cpp

diff --git a/ginac/parser/parse_context.cpp b/ginac/parser/parse_context.cpp
index 71b1748685c75a66dcee99df4003001c6b13073d..2230d614913fe56fe9a7feb82d5a1070d363092a 100644 (file)
--- a/ginac/parser/parse_context.cpp
+++ b/ginac/parser/parse_context.cpp
@@ -1,22 +1,38 @@
+/** @file parse_context.cpp
+ *
+ *  Implementation of the parser context. */
+
+/*
+ *  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
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
 #include "parse_context.h"
+
 #include <sstream>
 #include <stdexcept>
-namespace GiNaC
-{
 
-symbol
+namespace GiNaC {
+
+ex
 find_or_insert_symbol(const std::string& name, symtab& syms, const bool strict)
 {
        symtab::const_iterator p = syms.find(name);
-       if (p != syms.end()) {
-               if (is_a<symbol>(p->second))
-                       return ex_to<symbol>(p->second);
-               else
-                       throw std::invalid_argument(
-                               std::string("find_or_insert_symbol: name \"")
-                               + name + "\" does not correspond to a symbol");
-       }
-
+       if (p != syms.end())
+               return p->second;
 
        if (strict)
                throw std::invalid_argument(
@@ -28,5 +44,4 @@ find_or_insert_symbol(const std::string& name, symtab& syms, const bool strict)
        return sy;
 }
 
-}
-
+} // namespace GiNaC