From: Matt S Trout <mst@shadowcat.co.uk>
Date: Sat, 4 Dec 2010 17:20:51 +0000 (+0000)
Subject: initial import
X-Git-Tag: v1.000000~7
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=6f914695d80ef46fe45ac39758eb956f0f5389a6;p=p5sagit%2FEval-WithLexicals.git

initial import
---

6f914695d80ef46fe45ac39758eb956f0f5389a6
diff --git a/bin/tinyrepl b/bin/tinyrepl
new file mode 100644
index 0000000..352ad97
--- /dev/null
+++ b/bin/tinyrepl
@@ -0,0 +1,19 @@
+use strictures 1;
+use Eval::WithLexicals;
+use Term::ReadLine;
+use Data::Dumper::Concise;
+use Try::Tiny;
+
+my $eval = Eval::WithLexicals->new;
+my $read = Term::ReadLine->new('Perl REPL');
+while (1) {
+  my $line = $read->readline('re.pl$ ');
+  exit unless defined $line;
+  my @ret; try {
+    local $SIG{INT} = sub { die "Caught SIGINT" };
+    @ret = $eval->eval($line);
+  } catch {
+    @ret = ("Error!", $_);
+  };
+  print Dumper @ret;
+}
diff --git a/lib/Eval/WithLexicals.pm b/lib/Eval/WithLexicals.pm
new file mode 100644
index 0000000..1517ef7
--- /dev/null
+++ b/lib/Eval/WithLexicals.pm
@@ -0,0 +1,87 @@
+package Eval::WithLexicals;
+
+use Moo;
+use Sub::Quote;
+
+has lexicals => (is => 'rw', default => quote_sub q{ {} });
+
+{
+  my %valid_contexts = map +($_ => 1), qw(list scalar void);
+
+  has context => (
+    is => 'rw', default => quote_sub(q{ 'list' }),
+    isa => sub {
+      my ($val) = @_;
+      die "Invalid context type $val - should be list, scalar or void"
+	unless $valid_contexts{$val};
+    },
+  );
+}
+
+has in_package => (
+  is => 'rw', default => quote_sub q{ 'Eval::WithLexicals::Scratchpad' }
+);
+
+sub eval {
+  my ($self, $to_eval) = @_;
+  local *Eval::WithLexicals::Cage::current_line;
+  local *Eval::WithLexicals::Cage::pad_capture;
+  local *Eval::WithLexicals::Cage::grab_captures;
+  my $setup = Sub::Quote::capture_unroll('$_[2]', $self->lexicals, 2);
+  my $package = $self->in_package;
+  local our $current_code = qq!use strictures 1;
+${setup}
+sub Eval::WithLexicals::Cage::current_line {
+package ${package};
+${to_eval}
+;sub Eval::WithLexicals::Cage::pad_capture { }
+BEGIN { Eval::WithLexicals::Util::capture_list() }
+sub Eval::WithLexicals::Cage::grab_captures {
+  no warnings 'closure'; no strict 'refs';
+  package Eval::WithLexicals::Cage;!;
+  $self->_eval_do(\$current_code, $self->lexicals);
+  my @ret;
+  my $ctx = $self->context;
+  if ($ctx eq 'list') {
+    @ret = Eval::WithLexicals::Cage::current_line();
+  } elsif ($ctx eq 'scalar') {
+    $ret[0] = Eval::WithLexicals::Cage::current_line();
+  } else {
+    Eval::WithLexicals::Cage::current_line();
+  }
+  $self->lexicals({
+    %{$self->lexicals},
+    %{Eval::WithLexicals::Cage::grab_captures()}
+  });
+  @ret;
+}
+
+sub _eval_do {
+  my ($self, $text_ref) = @_;
+  local @INC = (sub {
+    if ($_[1] eq '/eval_do') {
+      open my $fh, '<', $text_ref;
+      $fh;
+    } else {
+      ();
+    }
+  }, @INC);
+  do '/eval_do' or die "Error: $@\nCompiling: $$text_ref";
+}
+
+{
+  package Eval::WithLexicals::Util;
+
+  use B qw(svref_2object);
+
+  sub capture_list {
+    my $pad_capture = \&Eval::WithLexicals::Cage::pad_capture;
+    my @names = map $_->PV, grep $_->isa('B::PV'),
+      svref_2object($pad_capture)->OUTSIDE->PADLIST->ARRAYelt(0)->ARRAY;
+    $Eval::WithLexicals::current_code .=
+      '+{ '.join(', ', map "'$_' => \\$_", @names).' };'
+      ."\n}\n}\n1;\n";
+  }
+}
+
+1;
diff --git a/t/simple.t b/t/simple.t
new file mode 100644
index 0000000..e4316f3
--- /dev/null
+++ b/t/simple.t
@@ -0,0 +1,30 @@
+use strictures 1;
+use Test::More;
+use Eval::WithLexicals;
+
+my $eval = Eval::WithLexicals->new;
+
+is_deeply(
+  [ $eval->eval('my $x; $x++; $x;') ],
+  [ 1 ],
+  'Basic eval ok'
+);
+
+is_deeply(
+  $eval->lexicals, { '$x' => \1 },
+  'Lexical stored ok'
+);
+
+is_deeply(
+  [ $eval->eval('$x+1') ],
+  [ 2 ],
+  'Use lexical ok'
+);
+
+is_deeply(
+  [ $eval->eval('{ my $x = 0 }; $x') ],
+  [ 1 ],
+  'Inner scope plus lexical ok'
+);
+
+done_testing;