Class: Alda::Chord

Inherits:
Event
  • Object
show all
Includes:
EventList
Defined in:
lib/alda-rb/event.rb

Overview

A chord event. Includes Alda::EventList.

An Alda::EventContainer containing an Alda::Chord can be created using event list sugar. See Alda::EventList#method_missing.

Alda::Score.new do
  p x{ c; e; g }.event.class # => Alda::Chord
end

The event contained by an Alda::EventContainer can become an Alda::Chord by using Alda::EventContainer#/.

Instance Attribute Summary

Attributes included from EventList

#events, #variables

Attributes inherited from Event

#container, #parent

Instance Method Summary collapse

Methods included from EventList

#==, #events_alda_codes, #has_variable?, #import, #method_missing, #on_contained, #to_a

Methods inherited from Event

#==, #detach_from_parent, #is_event_of?, #on_contained

Constructor Details

#initialize(*events, &block) ⇒ Chord

:call-seq:

new(*events, &block) -> Alda::Chord

There is an event list sugar invoking this method. See Alda::EventList#method_missing.

In most cases, events should be empty. Note that events cannot be specified using the sugar. block is to be passed with the chord object as self.

Alda::Score.new { piano_; x { c; -e; g } }.play
# (plays chord Cm)



762
763
764
765
766
 
# File 'lib/alda-rb/event.rb', line 762

def initialize *events, &block
	events.each { _1.parent = self if _1.is_a? Alda::Event }
	@events = events
	super &block
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Alda::EventList

Instance Method Details

#to_alda_code ⇒ Object

:call-seq:

to_alda_code() -> String

Overrides Alda::Event#to_alda_code.

Behaves differently for Alda 1 and Alda 2: because Alda 2 does not allow octave changes as part of a chord (something like a/>/c, and we have to write a>/c or a/>c instead) (alda-lang/alda#383), the code generated by this method will omit the slash before an octave change.

Alda.generation = :v1
Alda::Score.new { a/o!/c; a/o5/c }.to_s # => "a/>/c a/o5/c"
Alda.generation = :v2
Alda::Score.new { a/o!/c; a/o5/c }.to_s # => "a>/c a o5/c"



784
785
786
787
788
789
790
791
792
793
794
795
796
 
# File 'lib/alda-rb/event.rb', line 784

def to_alda_code
	return events_alda_codes ?/ if Alda.v1?
	@events.each_with_index.with_object '' do |(event, i), result|
		if i == 0
			# concat nothing
		elsif event.is_event_of? Alda::Octave
			result.concat ' ' unless event.num.empty?
		else
			result.concat '/'
		end
		result.concat event.to_alda_code
	end
end