Name

       App::Sqitch::Plan::ChangeList - Sqitch deployment plan change list

Synopsis

         my $list = App::Sqitch::Plan::ChangeList->new(
             $add_roles,
             $add_users,
             $insert_user,
             $insert_user2,
         );

         my @changes = $list->changes;
         my $add_users = $list->change_at(1);
         my $add_users = $list->get('add_users');

         my $insert_user1 = $list->get('insert_user@alpha');
         my $insert_user2 = $list->get('insert_user');

Description

       This module is used internally by App::Sqitch::Plan to manage plan changes.  It's modeled
       on Array::AsHash and Hash::MultiValue, but makes allowances for finding changes relative
       to tags.

Interface

   Constructors
       "new"

         my $plan = App::Sqitch::Plan::ChangeList->new( @changes );

       Instantiates and returns a App::Sqitch::Plan::ChangeList object with the list of changes.
       Each change should be a App::Sqitch::Plan::Change object. Order will be preserved but the
       location of each change will be indexed by its name and ID, as well as the names and IDs
       of any associated tags.

   Instance Methods
       "count"

         my $count = $changelist->count;

       Returns the number of changes in the list.

       "changes"

         my @changes = $changelist->changes;

       Returns all of the changes in the list.

       "tags"

         my @tags = $changelist->tags;

       Returns all of the tags associated with changes in the list.

       "items"

         my @changes = $changelist->items;

       An alias for "changes".

       "change_at"

         my $change = $change_list->change_at(10);

       Returns the change at the specified index.

       "index_of"

         my $index = $changelist->index_of($change_id);
         my $index = $changelist->index_of($change_name);

       Returns the index of the change with the specified ID or name. The value passed may be one
       of these forms:

       •   An ID

             my $index = $changelist->index_of('6c2f28d125aff1deea615f8de774599acf39a7a1');

           This is the SHA1 ID of a change or tag. Currently, the full 40-character hexed hash
           string must be specified.

       •   A change name

             my $index = $changelist->index_of('users_table');

           The name of a change. Will throw an exception if the more than one change in the list
           goes by that name.

       •   A tag name

             my $index = $changelist->index_of('@beta1');

           The name of a tag, including the leading "@".

       •   A tag-qualified change name

             my $index = $changelist->index_of('users_table@beta1');

           The named change as it was last seen in the list before the specified tag.

       "first_index_of"

         my $index = $changelist->first_index_of($change_name);
         my $index = $changelist->first_index_of($change_name, $name);

       Returns the index of the first instance of the named change in the list. If a second
       argument is passed, the index of the first instance of the change after the index of the
       second argument will be returned. This is useful for getting the index of a change as it
       was deployed after a particular tag, for example:

         my $index = $changelist->first_index_of('foo', '@beta');
         my $index = $changelist->first_index_of('foo', 'users_table@beta1');

       The second argument must unambiguously refer to a single change in the list. As such, it
       should usually be a tag name or tag-qualified change name. Returns "undef" if the change
       does not appear in the list, or if it does not appear after the specified second argument
       change name.

       "last_change"

         my $change = $changelist->last_change;

       Returns the last change to be appear in the list. Returns "undef" if the list contains no
       changes.

       "last_tagged_change"

         my $change = $changelist->last_tagged_change;

       Returns the last tagged change in the list. Returns "undef" if the list contains no tagged
       changes.

       "index_of_last_tagged"

         my $index = $changelist->index_of_last_tagged;

       Returns the index of the last tagged change in the list. Returns "undef" if the list
       contains no tags.

       "get"

         my $change = $changelist->get($id);
         my $change = $changelist->get($change_name);
         my $change = $changelist->get($tag_name);

       Returns the change for the specified ID or name. The name may be specified as described
       for "index_of()". An exception will be thrown if more than one change goes by a specified
       name. As such, it is best to specify it as unambiguously as possible: as a tag name, a
       tag-qualified change name, or an ID.

       "contains"

         say 'Yes!' if $plan->contains('6c2f28d125aff1deea615f8de774599acf39a7a1');

       Like "index_of()", but never throws an exception, and returns true if the plan contains
       the specified change, and false if it does not.

       "find"

         my $change = $changelist->find($id);
         my $change = $changelist->find($change_name);
         my $change = $changelist->find($tag_name);
         my $change = $changelist->find("$change_name\@$tag_name");

       Tries to find and return a change based on the argument. If no tag is specified, finds and
       returns the first instance of the named change. Otherwise, it returns the change as of the
       specified tag. Unlike "get()", it will not throw an error if more than one change exists
       with the specified name, but will return the first instance.

       "append"

         $changelist->append(@changes);

       Append one or more changes to the list. Does not check for duplicates, so use with care.

       "index_tag"

         $changelist->index_tag($index, $tag);

       Index the tag at the specified index. That is, the tag is assumed to be associated with
       the change at the specified index, and so the internal look up table is updated so that
       the change at that index can be found via the tag's name and ID.

See Also

       App::Sqitch::Plan
           The Sqitch plan.

Author

       David E. Wheeler <david@justatheory.com>

License

       Copyright (c) 2012-2022 iovation Inc., David E. Wheeler

       Permission is hereby granted, free of charge, to any person obtaining a copy of this
       software and associated documentation files (the "Software"), to deal in the Software
       without restriction, including without limitation the rights to use, copy, modify, merge,
       publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
       to whom the Software is furnished to do so, subject to the following conditions:

       The above copyright notice and this permission notice shall be included in all copies or
       substantial portions of the Software.

       THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
       INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
       PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
       FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
       OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
       DEALINGS IN THE SOFTWARE.