# For making sure that no conflicts occur
package SymTab;
use Carp;
sub new {
        my($type,%ids) = @_;
        my($this) = bless {
                Id2Sym => {},
                Sym2Id => {},
                IsPar => {},
        }, $type;
        $this->add_ids(%ids);
        $this;
}
sub add_ids {
        my($this,%hash) = @_;
        for(keys %hash) {
                $this->{Id2Sym}{$_} = $hash{$_};
                 
                # This usually sets the 'undef' key to whatever is in $_, because the
                # object in $hash{$_} is usually a scalar, not an array. I know this
                # becuase this function is called by AddArgsyms in PDL::PP, which
                # conructs the %hash to be
                # 
                #   sym_name => sym_name
                # 
                # The only other place that invokes this code is the constructor,
                # which itself is called by MkDefSyms in PDL::PP. That invocation is
                # called with %hash set as
                # 
                #   _PDL_ThisTrans => ["__privtrans",C::Type->new(undef,"$_[0] *foo")]
                # 
                # AFAIK, Sym2Id is never used anywhere in the code generation, and
                # the setting of undef throws warning messages, so I am going to
                # comment-out this line for now.  --David Mertens, 12-12-2011
                #$this->{Sym2Id}{$hash{$_}->[0]} = $_;
        }
}
sub add_params {
        my($this,%hash) = @_;
        $this->add_ids(%hash);
        for(keys %hash) {
                $this->{IsPar}{$_} = 1;
        }
}
sub decl_locals {
        my($this) = @_;
        my $str;
        for(keys %{$this->{Id2Sym}}) {
                if(!$this->{IsPar}{$_}) {
                        $str .= $this->{Id2Sym}{$_}[1]
                                   ->get_decl($this->{Id2Sym}{$_}[0]).";";
                }
        }
        $str;
}
sub get_params {
}
sub get_symname {
        my($this,$id) = @_;
        confess "Symbol not found: $id\n" if(!defined($this->{Id2Sym}{$id}));
        return $this->{Id2Sym}{$id}[0];
}
1;