perl6/env.pm

   1 unit class MalEnv;
   2 use types;
   3
   4 has $.outer;
   5 has %.data;
   6 has @.binds;
   7 has @.exprs;
   8
   9 method new ($outer?, @binds?, @exprs?) {
  10   self.bless(:$outer, :@binds, :@exprs);
  11 }
  12
  13 submethod BUILD (:@!binds, :@!exprs, :$!outer, :%!data) {
  14   for @!binds.kv -> $idx, $key {
  15     if $key eq '&' {
  16       my $value = MalList([@!exprs[$idx..*]]);
  17       self.set(@!binds[$idx+1], $value);
  18       last;
  19     }
  20     my $value = @!exprs[$idx];
  21     self.set($key, $value);
  22   }
  23 }
  24
  25 method set ($key, $value) {
  26   %.data{$key} = $value;
  27 }
  28
  29 method find ($key) {
  30   return %.data{$key} ?? self !! $.outer && $.outer.find($key);
  31 }
  32
  33 method get ($key) {
  34   my $env = self.find($key) or die X::MalNotFound.new(name => $key);
  35   return $env.data{$key};
  36 }