package lexconstants;

sub import {
  shift;
  my %h = @_;
  my $caller = caller;  

  for my $name (keys %h) {
    *{$caller . "::$name"} = sub () { lexconstants::value($name) }
      unless defined &{$caller . "::$name"};
  }

  $^H{lexconstants} = \ %h;
}

sub unimport {
  $^H{lexconstants} = undef;
}

sub value {
    my ($name) = @_;
    (caller(0))[10]{$name} or warn "Undefined constant $name..."
}