the input parser now handles (simple) indexed objects; the indices to be used

[ginac.git] / ginac / input_parser.yy

diff --git a/ginac/input_parser.yy b/ginac/input_parser.yy
index d3ffd1955abc312cb7d636cf7fbbca3a5be47bdf..c5c78d2dd9cf4656e44d9825f851c1018c01fd7b 100644 (file)
--- a/ginac/input_parser.yy
+++ b/ginac/input_parser.yy
@@ -36,6 +36,8 @@
 #include "lst.h"
 #include "power.h"
 #include "exprseq.h"
 #include "lst.h"
 #include "power.h"
 #include "exprseq.h"

+#include "idx.h"
+#include "indexed.h"

 #include "matrix.h"
 #include "inifcns.h"
 
 #include "matrix.h"
 #include "inifcns.h"
 


@@ -48,6 +50,9 @@ ex parsed_ex;
 
 // Last error message returned by parser
 static std::string parser_error;
 
 // 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
 %}
 
 /* Tokens (T_LITERAL means a literal value returned by the parser, but not


@@ -62,6 +67,7 @@ static std::string parser_error;
 %left '*' '/' '%'
 %nonassoc NEG
 %right '^'
 %left '*' '/' '%'
 %nonassoc NEG
 %right '^'

+%left '.' '~'

 %nonassoc '!'
 
 %start input
 %nonassoc '!'
 
 %start input


@@ -89,12 +95,12 @@ exp : T_NUMBER              {$$ = $1;}
                if (is_lexer_symbol_predefined($1))
                        $$ = $1.eval();
                else
                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 ')' {
        }
        | T_LITERAL             {$$ = $1;}
        | T_DIGITS              {$$ = $1;}
        | T_SYMBOL '(' exprseq ')' {

-               std::string n = ex_to<symbol>($1).get_name();
+               std::string n = get_symbol_name($1);

                if (n == "sqrt") {
                        if ($3.nops() != 1)
                                throw (std::runtime_error("too many arguments to sqrt()"));
                if (n == "sqrt") {
                        if ($3.nops() != 1)
                                throw (std::runtime_error("too many arguments to sqrt()"));


@@ -117,6 +123,8 @@ exp : T_NUMBER              {$$ = $1;}
        | '-' exp %prec NEG     {$$ = -$2;}
        | '+' exp %prec NEG     {$$ = $2;}
        | exp '^' exp           {$$ = pow($1, $3);}
        | '-' 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 '}' {$$ = $2;}
        | exp '!'               {$$ = factorial($1);}
        | '(' exp ')'           {$$ = $2;}
        | '{' list_or_empty '}' {$$ = $2;}


@@ -149,6 +157,30 @@ 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)
 {
 // Get last error encountered by parser
 std::string get_parser_error(void)
 {