[bugfix] parser::parse_literal_expr(): don't forget to consume the token...

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

diff --git a/ginac/parser/parser.cpp b/ginac/parser/parser.cpp
index 0ee682ab7f108bc60a6a47d1141b65208a461abb..6cac523c38625d8bddad69dcbc648d4b629665c4 100644 (file)
--- a/ginac/parser/parser.cpp
+++ b/ginac/parser/parser.cpp
@@ -60,21 +60,25 @@ ex parser::parse_paren_expr()
 }
 
 extern numeric* _num_1_p;
+extern ex _ex0;
 
 /// unary_expr: [+-] expression
-ex parser::parse_unary_expr(const int s)
+ex parser::parse_unary_expr()
 {
-       // consume '-' (or '+')
-       get_next_tok();
-       ex v = parse_expression();
-       switch (s) {
-               case '-':
-                       return (new mul(v, *_num_1_p))->setflag(status_flags::dynallocated);
-               case '+':
-                       return v;
-               default:
-                       Parse_error_("invalid unary operator \"" << char(s) << "\"");
-       }
+       // Unlike most other parse_* method this one does NOT consume
+       // current token so parse_binop_rhs() knows what kind of operator
+       // is being parsed.
+       
+       // There are different kinds of expressions which need to be handled:
+       // -a+b 
+       // -(a) 
+       // +a
+       // +(a)
+       // Delegete the work to parse_binop_rhs(), otherwise we end up
+       // duplicating it here. 
+       ex lhs = _ex0; // silly trick
+       ex e = parse_binop_rhs(0, lhs);
+       return e;
 }
 
 /// primary: identifier_expr | number_expr | paren_expr | unary_expr 
@@ -88,9 +92,8 @@ ex parser::parse_primary()
                case '(': 
                         return parse_paren_expr();
                case '-':
-                        return parse_unary_expr('-');
                case '+':
-                        return parse_unary_expr('+');
+                        return parse_unary_expr();
                case lexer::token_type::literal:
                         return parse_literal_expr();
                case lexer::token_type::eof:
@@ -118,6 +121,7 @@ ex parser::parse_number_expr()
 /// literal_expr: 'I' | 'Pi' | 'Euler' | 'Catalan'
 ex parser::parse_literal_expr()
 {
+       get_next_tok(); // consume the literal
        if (scanner->str == "I")
                return I;
        else if (scanner->str == "Pi")