- prepared for 1.0.13 release

[ginac.git] / ginac / input_parser.yy

diff --git a/ginac/input_parser.yy b/ginac/input_parser.yy
index bbc07647e80d5459f634c9890a2b336d2799e43a..c4f69c26d39aeb7c13121242d4a23c59de7ce938 100644 (file)
--- a/ginac/input_parser.yy
+++ b/ginac/input_parser.yy
@@ -4,7 +4,7 @@
  *  This file must be processed with yacc/bison. */
 
 /*
- *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2003 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
@@ -36,6 +36,8 @@
 #include "lst.h"
 #include "power.h"
 #include "exprseq.h"
+#include "idx.h"
+#include "indexed.h"
 #include "matrix.h"
 #include "inifcns.h"
 
@@ -48,11 +50,14 @@ ex parsed_ex;
 
 // Last error message returned by parser
 static std::string parser_error;
+
+// Prototypes
+ex attach_index(const ex & base, ex i, bool covariant);
 %}
 
 /* Tokens (T_LITERAL means a literal value returned by the parser, but not
    of class numeric or symbol (e.g. a constant or the FAIL object)) */
-%token T_NUMBER T_SYMBOL T_LITERAL T_DIGITS T_EQUAL T_NOTEQ T_LESSEQ T_GREATEREQ
+%token T_EOF T_NUMBER T_SYMBOL T_LITERAL T_DIGITS T_EQUAL T_NOTEQ T_LESSEQ T_GREATEREQ
 
 /* Operator precedence and associativity */
 %right '='
@@ -62,6 +67,7 @@ static std::string parser_error;
 %left '*' '/' '%'
 %nonassoc NEG
 %right '^'
+%left '.' '~'
 %nonassoc '!'
 
 %start input
@@ -72,7 +78,7 @@ static std::string parser_error;
  */
 
 %%
-input  : exp {
+input  : exp T_EOF {
                try {
                        parsed_ex = $1;
                        YYACCEPT;
@@ -81,7 +87,6 @@ input : exp {
                        YYERROR;
                }
        }
-       | error         {yyclearin; yyerrok;}
        ;
 
 exp    : T_NUMBER              {$$ = $1;}
@@ -89,13 +94,20 @@ exp : T_NUMBER              {$$ = $1;}
                if (is_lexer_symbol_predefined($1))
                        $$ = $1.eval();
                else
-                       throw (std::runtime_error("unknown symbol '" + ex_to<symbol>($1).get_name() + "'"));
+                       throw (std::runtime_error("unknown symbol '" + get_symbol_name($1) + "'"));
        }
        | T_LITERAL             {$$ = $1;}
        | T_DIGITS              {$$ = $1;}
        | T_SYMBOL '(' exprseq ')' {
-               unsigned i = function::find_function(ex_to<symbol>($1).get_name(), $3.nops());
-               $$ = function(i, ex_to<exprseq>($3)).eval(1);
+               std::string n = get_symbol_name($1);
+               if (n == "sqrt") {
+                       if ($3.nops() != 1)
+                               throw (std::runtime_error("too many arguments to sqrt()"));
+                       $$ = sqrt($3.op(0));
+               } else {
+                       unsigned i = function::find_function(n, $3.nops());
+                       $$ = function(i, ex_to<exprseq>($3)).eval(1);
+               }
        }
        | exp T_EQUAL exp       {$$ = $1 == $3;}
        | exp T_NOTEQ exp       {$$ = $1 != $3;}
@@ -110,6 +122,8 @@ exp : T_NUMBER              {$$ = $1;}
        | '-' exp %prec NEG     {$$ = -$2;}
        | '+' exp %prec NEG     {$$ = $2;}
        | exp '^' exp           {$$ = pow($1, $3);}
+       | exp '.' exp           {$$ = attach_index($1, $3, true);}
+       | exp '~' exp           {$$ = attach_index($1, $3, false);}
        | exp '!'               {$$ = factorial($1);}
        | '(' exp ')'           {$$ = $2;}
        | '{' list_or_empty '}' {$$ = $2;}
@@ -142,6 +156,30 @@ row        : exp                   {$$ = lst($1);}
  */
 
 %%
+// Attach index to expression
+ex attach_index(const ex & base, ex i, bool covariant)
+{
+       // Toggle index variance if necessary
+       if (is_a<varidx>(i)) {
+               const varidx &vi = ex_to<varidx>(i);
+               if (vi.is_covariant() != covariant)
+                       i = vi.toggle_variance();
+       } else if (!covariant)
+               throw (std::runtime_error("index '" + get_symbol_name(i) + "' is not a varidx and cannot be contravariant"));
+
+       // Add index to an existing indexed object, or create a new indexed
+       // object if there are no indices yet
+       if (is_a<indexed>(base)) {
+               const ex &b = base.op(0);
+               exvector iv;
+               for (unsigned n=1; n<base.nops(); n++)
+                       iv.push_back(base.op(n));
+               iv.push_back(i);
+               return indexed(b, iv);
+       } else
+               return indexed(base, i);
+}
+
 // Get last error encountered by parser
 std::string get_parser_error(void)
 {