ginsh: use exmap for storing assigned symbols.

[ginac.git] / ginsh / ginsh_parser.yy

diff --git a/ginsh/ginsh_parser.yy b/ginsh/ginsh_parser.yy
index b8c6875a2f96da32fb99817c3e82c5c5334222b7..0594d9488b585d4ecb720a23d3457f09d8ef1bdf 100644 (file)
--- a/ginsh/ginsh_parser.yy
+++ b/ginsh/ginsh_parser.yy
@@ -64,6 +64,8 @@ static const char *orig_basic_word_break_characters;
 // Expression stack for %, %% and %%%
 static void push(const ex &e);
 static ex exstack[3];
+// Assigned symbols
+static exmap assigned_symbol_table;
 
 // Start and end time for the time() function
 #ifdef HAVE_RUSAGE
@@ -237,7 +239,13 @@ line       : ';'
        ;
 
 exp    : T_NUMBER              {$$ = $1;}
-       | T_SYMBOL              {$$ = $1.eval();}
+       | T_SYMBOL              {
+               exmap::const_iterator i = assigned_symbol_table.find($1);
+               if (i == assigned_symbol_table.end())
+                       $$ = $1;
+               else
+                       $$ = i->second.eval();
+       }
        | '\'' T_SYMBOL '\''    {$$ = $2;}
        | T_LITERAL             {$$ = $1;}
        | T_DIGITS              {$$ = $1;}
@@ -253,7 +261,7 @@ exp : T_NUMBER              {$$ = $1;}
                }
        }
        | T_DIGITS '=' T_NUMBER {$$ = $3; Digits = ex_to<numeric>($3).to_int();}
-       | T_SYMBOL '=' exp      {$$ = $3; const_cast<symbol&>(ex_to<symbol>($1)).assign($3);}
+       | T_SYMBOL '=' exp      {$$ = $3; assigned_symbol_table[$1] = $3; }
        | exp T_EQUAL exp       {$$ = $1 == $3;}
        | exp T_NOTEQ exp       {$$ = $1 != $3;}
        | exp '<' exp           {$$ = $1 < $3;}
@@ -567,7 +575,9 @@ static ex f_transpose(const exprseq &e)
 static ex f_unassign(const exprseq &e)
 {
        CHECK_ARG(0, symbol, unassign);
-       const_cast<symbol&>(ex_to<symbol>(e[0])).unassign();
+       exmap::iterator i = assigned_symbol_table.find(e[0]);
+       if (i != assigned_symbol_table.end())
+               assigned_symbol_table.erase(i);
        return e[0];
 }
 
@@ -900,6 +910,7 @@ int main(int argc, char **argv)
        // Print banner in interactive mode
        if (isatty(0)) 
                greeting();
+       assigned_symbol_table = exmap();
 
        // Init function table
        insert_fcns(builtin_fcns);