grammar.txt

lexid   Spaces

//
//      Output Options
//
%CONTEXT [[std::ostream &]]

%ON_ERROR [[
    $c <<"COL#" <<$pos.m_Col <<": " <<$message <<'\n';
]]

%EXTRA_TOKENS   [[dec_num|oct_num|hex_num|spaces]]
%SHOW_UNDEFINED

//
//      Operator Precedence
//
left   + -
left   * / %
right  ( )

//
//      Grammar with Reduction Code
//
<@> ::= <Expr>  [[
    $r = $1;
]]

<Expr> ::= <Expr> + <Expr>  [[
    bux::unlex<int>($1) += bux::unlex<int>($3);
    $r = $1;
]]
<Expr> ::= <Expr> - <Expr>  [[
    bux::unlex<int>($1) -= bux::unlex<int>($3);
    $r = $1;
]]
<Expr> ::= <Expr> * <Expr>  [[
    bux::unlex<int>($1) *= bux::unlex<int>($3);
    $r = $1;
]]
<Expr> ::= <Expr> / <Expr>  [[
    bux::unlex<int>($1) /= bux::unlex<int>($3);
    $r = $1;
]]
<Expr> ::= <Expr> % <Expr>  [[
    bux::unlex<int>($1) %= bux::unlex<int>($3);
    $r = $1;
]]
<Expr> ::= ( <Expr> )       [[
    $r = $2;
]]
<Expr> ::= $Num             [[
    $r = bux::createLex(dynamic_cast<bux::C_IntegerLex&>(*$1).value<int>());
]]