Remove dependency on List::MoreUtils

Current LMU maintainer was proven unresponsive to concerns about the towering
complexity of that modules dependency chain. Use a pure-perl implementation
of uniq() compatible with the version in LMU 0.4xx series

The slowdown, while noticeable, is of no consequence to the larger codebase

~$ dd if=/dev/urandom bs=512 count=1 2>/dev/null | perl -0777 -Ilib -MSQL::Translator::Utils -MList::MoreUtils::XS -MBenchmark::Dumb -e '
  my @list = map ord, split "", <>;

  Benchmark::Dumb::cmpthese( 0.0001 => {
    lmu => sub {
      List::MoreUtils::uniq(@list);
    },
    pp => sub {
      SQL::Translator::Utils::uniq(@list);
    }
  })
'
               Rate    pp    lmu
pp  2838.17+-0.28/s    -- -35.2%
lmu 4381.99+-0.44/s 54.4%     --

Changes

@@ -2,6 +2,7 @@ Changes for SQL::Translator
 
  * Add support for monotonically increasing SQLite autoincs (GH#47)
  * Declare dependencies in deterministic order (RT#102859)
+ * Remove dependency on List::MoreUtils ( http://is.gd/lmu_cac_debacle )
 
 0.11021 2015-01-29
 

Makefile.PL

@@ -18,7 +18,6 @@ my $deps = {
     'Package::Variant'         => '1.001001',
     'Sub::Quote'               => '0',
     'Try::Tiny'                => '0.04',
-    'List::MoreUtils'          => '0.09',
     'Scalar::Util'             => '0',
   },
   recommends => {

lib/SQL/Translator/Role/ListAttr.pm

@@ -22,8 +22,7 @@ attributes.
 
 =cut
 
-use SQL::Translator::Utils qw(parse_list_arg ex2err);
-use List::MoreUtils qw(uniq);
+use SQL::Translator::Utils qw(parse_list_arg ex2err uniq);
 use Sub::Quote qw(quote_sub);
 
 use Package::Variant (

lib/SQL/Translator/Schema/Trigger.pm

@@ -29,9 +29,8 @@ C<SQL::Translator::Schema::Trigger> is the trigger object.
 =cut
 
 use Moo;
-use SQL::Translator::Utils qw(parse_list_arg ex2err throw);
+use SQL::Translator::Utils qw(parse_list_arg ex2err throw uniq);
 use SQL::Translator::Types qw(schema_obj enum);
-use List::MoreUtils qw(uniq);
 use Sub::Quote qw(quote_sub);
 
 extends 'SQL::Translator::Schema::Object';

lib/SQL/Translator/Utils.pm

@@ -16,7 +16,7 @@ our @EXPORT_OK = qw(
     debug normalize_name header_comment parse_list_arg truncate_id_uniquely
     $DEFAULT_COMMENT parse_mysql_version parse_dbms_version
     ddl_parser_instance batch_alter_table_statements
-    throw ex2err carp_ro
+    uniq throw ex2err carp_ro
     normalize_quote_options
 );
 use constant COLLISION_TAG_LENGTH => 8;
@@ -366,6 +366,15 @@ sub _find_co_root {
     }
 }
 
+sub uniq {
+  my( %seen, $seen_undef, $numeric_preserving_copy );
+  grep { not (
+    defined $_
+      ? $seen{ $numeric_preserving_copy = $_ }++
+      : $seen_undef++
+  ) } @_;
+}
+
 sub throw {
     die SQL::Translator::Utils::Error->new($_[0]);
 }