[Ace] Event Tag Reader

#==============================================================================
# Iavra Event Tag Reader 1.06
# -----------------------------------------------------------------------------
# Description:
# Offers a generic hook for other scripts to read notetags from the current
# page of event.
# -----------------------------------------------------------------------------
# Prerequisites:
# None
# -----------------------------------------------------------------------------
# How to Use:
#
# Register a regex in your script like this:
#
# IAVRA::EVENT_TAGS.register(:key, /regex/, :int, :int)
#
# This will attempt to capture the first 2 groups from your regex and convert
# them to integers. Everything less than 2 will be set to nil in the result,
# while everything more than 2 will be discarded.
#
# Get the matches for that regex during runtime like this:
#
# IAVRA::EVENT_TAGS.get_all(event_id, :key)    # returns all matches.
# IAVRA::EVENT_TAGS.get(event_id, :key)        # returns the first match.
# IAVRA::EVENT_TAGS.get(event_id, :key, index) # returns the (index)th match.
#
# Each match is an array containing your captured groups.
# -----------------------------------------------------------------------------
# Terms of Use:
# Free to use for both commercial and non-commercial games. Please give credit.
# -----------------------------------------------------------------------------
# Credits:
# Iavra
# -----------------------------------------------------------------------------
# Changelog:
# - 1.01: Added support for named capture groups.
# - 1.02: Renamed get to get_all and added a new get method for direct access.
# - 1.03: Added an $imported entry for the script.
# - 1.04: Shortened the hash building.
# - 1.05: Rebuilt the script. Support for named groups was discarded, since i
#         figured those don't get used much, anyway.
# - 1.06: Reduced the number of iterations to improve performance.
#==============================================================================

($imported ||= {})[:iavra_event_tags] = true

#==============================================================================
# ▼ IAVRA::EVENT_TAGS
#==============================================================================

module IAVRA
    module EVENT_TAGS

        #==========================================================================
        # ■ ■ ■ ■ ■ CONFIGURATION ■ ■ ■ ■ ■
        #==========================================================================

        #==========================================================================
        # Procs responsible for converting the captured groups. Nil values will be
        # checked beforehand, so the functions don't need to care about them.
        #==========================================================================

        CAPTURES = {
            :string => lambda {|value| value},
            :symbol => lambda {|value| value.to_sym},
            :int =>    lambda {|value| value.to_i},
            :float =>  lambda {|value| value.to_f}
        }

        #==========================================================================
        # ■ ■ ■ ■ ■ CONFIGURATION ■ ■ ■ ■ ■
        #==========================================================================

        #==========================================================================
        # String used to join multi-line comments together.
        #==========================================================================

        LINEBREAK = "\r\n"

        #==========================================================================
        # Instance variable used to store registered regexes.
        #==========================================================================

        class << self
            attr_reader :registered
        end

        @registered = {}

        #==========================================================================
        # Call this in your script to register your regex and its capture groups.
        # Make sure to pick an unused symbol as key.
        #==========================================================================

        def self.register(key, regex, *captures)
            @registered[key] = [regex, captures]
        end

        #==========================================================================
        # Gets all matches for a registered regex on an event.
        #==========================================================================

        def self.get_all(event_id, key)
            $game_map.events[event_id].iavra_event_tags[key] || []
        end

        #==========================================================================
        # Get one match for a registered regex on an event.
        #==========================================================================

        def self.get(event_id, key, index = 0)
            get_all(event_id, key)[index]
        end

    end
end

#==============================================================================
# ▼ Game_Event
#==============================================================================

class Game_Event < Game_Character

    attr_reader :iavra_event_tags

    alias :iavra_event_tags_setup_page :setup_page

    #============================================================================
    # Parses the event's notetags, whenever a page becomes active.
    #============================================================================

    def setup_page(*args)
        iavra_event_tags_setup_page(*args)
        iavra_event_tags_parse_notetags
    end

    #============================================================================
    # First collects all comments on the current page and afterwards iterates
    # over them, matching each comment against the registered regexes and storing
    # the captured groups.
    #============================================================================

    def iavra_event_tags_parse_notetags
        comments = (@page ? @page.list : []).reduce([]){|a, c|
            a << c.parameters[0] if [108, 408].include?(c.code); a
        }.join(IAVRA::EVENT_TAGS::LINEBREAK)
        @iavra_event_tags = Hash[IAVRA::EVENT_TAGS.registered.map{|k, d|
            [k, comments.scan(d[0]).map{d[1].map.with_index(1){|k, i|
                v = $~[i]; v ? IAVRA::EVENT_TAGS::CAPTURES[k].call(v) : nil
            }}]
        }]
    end

end