[Bps-public-commit] r12687 - in pie/branches/named-params: lib/PIE

[jesse at bestpractical.com]

Author: jesse
Date: Mon May 26 06:02:31 2008
New Revision: 12687

Modified:
   pie/branches/named-params/lib/PIE/Evaluator.pm
   pie/branches/named-params/t/let.t

Log:
* removing feature. same functionality. 

Modified: pie/branches/named-params/lib/PIE/Evaluator.pm
==============================================================================
--- pie/branches/named-params/lib/PIE/Evaluator.pm	(original)
+++ pie/branches/named-params/lib/PIE/Evaluator.pm	Mon May 26 06:02:31 2008
@@ -27,17 +27,6 @@
                      default => sub { {} },
 );
 
-has stack_vars => (
-    is => 'rw',
-    metaclass => 'Collection::Array',
-    isa       => 'ArrayRef[HashRef]',
-    default   => sub { [] },
-    provides  => {
-        'push' => 'push_stack_vars',
-        'pop'  => 'pop_stack_vars',
-    }
-);
-
 has stack_block => (
     is => 'rw',
     metaclass => 'Collection::Array',
@@ -61,16 +50,17 @@
     my %args = validate(@_, {args => 1, block => 1});
 
     $self->stack_depth($self->stack_depth+1);
-    $self->push_stack_vars($args{'args'});
     $self->push_stack_block($args{'block'});
 
-    push @{ $self->lex_block_map->{ $args{'block'}->block_id } ||= [] }, $#{ $self->stack_vars };
+    # lex_block_map is a mapping from a block id to an array of stack indexes.
+    # if we're entereing block 3, we push the current stack frame  onto the lex_block_map entry for block 3
+    #   The last entry of the current block is where we can see its lexical context
+    push @{ $self->lex_block_map->{ $args{'block'}->block_id } ||= [] }, $args{'args'};
 }
 
 sub leave_stack_frame {
     my $self = shift;
     die "Trying to leave stack frame 0. Too many returns. Something relaly bad happened" if ($self->stack_depth == 0);
-    $self->pop_stack_vars();
     my $block = $self->pop_stack_block();
     $self->stack_depth($self->stack_depth-1);
 
@@ -101,11 +91,15 @@
 sub lookup_lex_name {
     my ($self, $name) = @_;
 
-    return unless @{ $self->stack_block };
 
+    return unless @{ $self->stack_block };
+    # look at the current block on the stack
     my $block = $self->stack_block->[-1];
     do {
-        my $stack = $self->stack_vars->[ $self->lex_block_map->{ $block->block_id }[-1] ];
+        # grab the stack frame from the lexical block map pointer for the 'current' block (the one we're inspecting
+        my $stack =$self->lex_block_map->{ $block->block_id }[-1] ;
+        # if we find the variable, we can return it
+
         return $stack->{$name} if exists $stack->{$name};
     } while ($block = $block->outter_block);
 
@@ -114,9 +108,8 @@
 
 sub resolve_symbol_name {
     my ($self, $name) = @_;
-    my $stack = $self->stack_vars->[-1] || {};
     Carp::cluck if ref($name);
-    $stack->{$name} || $self->lookup_lex_name($name) || $self->get_global_symbol($name)
+    $self->lookup_lex_name($name) || $self->get_global_symbol($name)
         || die "Could not find symbol $name in the current lexical context.";
 }
 

Modified: pie/branches/named-params/t/let.t
==============================================================================
--- pie/branches/named-params/t/let.t	(original)
+++ pie/branches/named-params/t/let.t	Mon May 26 06:02:31 2008
@@ -27,9 +27,9 @@
 $eval->set_global_symbol( 'match-regexp' => $MATCH_REGEX );
 
 my $script =
-    $builder->defun(
+    $builder->defun( # outer block
     ops => [
-        { name => 'Let',
+        { name => 'Let', #inner block. each block has a lexical pad structure
             args => {
                 bindings => { REGEXP => 'software' },
                 nodes => [
@@ -42,7 +42,7 @@
                                 args => {
                                     regexp => { name => 'Symbol', args => { symbol => 'REGEXP' } },
                                     'tested-string' => 
-                                         { name => 'Symbol', args => { symbol => 'tested-string' } },
+                                         { name => 'Symbol', args => { symbol => 'tested-string' } }, # lookup to tested string needs to query the outer block's lexpad
                                     }
                                 }
                             }