Parser can parse (some) floating point numbers now.

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

diff --git a/ginac/parser/lexer.cpp b/ginac/parser/lexer.cpp
index ed1f894fea381bdc9c553d9a2811ff12b1697bcb..7c3e6c84aecf5ac6d62db29452de77f981791a95 100644 (file)
--- a/ginac/parser/lexer.cpp
+++ b/ginac/parser/lexer.cpp
@@ -35,13 +35,23 @@ int lexer::gettok()
                        return token_type::identifier;
        }
 
-       // Number: [0-9.]+
+       // Number: [0-9]+([.][0-9]*(eE[+-][0-9]+)*)*
        if (isdigit(c) || c == '.') {
                str = "";
                do {
                        str += c;
                        c = input->get();
                } while (isdigit(c) || c == '.');
+               if (c == 'E' || c == 'e') {
+                       str += 'E';
+                       c = input->get();
+                       if (isdigit(c))
+                               str += '+';
+                       do {
+                               str += c;
+                               c = input->get();
+                       } while (isdigit(c));
+               }
                return token_type::number;
        }
 
@@ -126,6 +136,21 @@ void lexer::switch_input(std::istream* in)
        input = in;
        line_num = 0;
        column = 0;
+       c = ' ';
+}
+
+/// Symbolic name of current token (for error reporting)
+std::string lexer::tok2str(const int tok) const
+{
+       switch (tok) {
+               case lexer::token_type::identifier:
+               case lexer::token_type::number:
+                       return std::string("\"") + str + "\"";
+               case lexer::token_type::eof:
+                       return std::string("EOF");
+               default:
+                       return std::string("\"") + char(tok) + "\"";
+       }
 }
 
 } // namespace GiNaC