Class: Alda::Note

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

Overview

A note event. An Alda::EventContainer containing an Alda::Note can be derived using Alda::EventList sugar. See Alda::EventList#method_missing.

There cannot be tildes and dots in (usual) ruby method names, so use underlines instead.

The accidentals can be added using #+@, #-@, and #~, or by using exclamation mark, question mark or underline.

Alda::Score.new do
  key_sig! [:d, :major]
  c4_2 d1108ms e2s
  f2!      # F sharp
  g20ms_4? # G flat
  a6_      # A natural
  c__      # C (slur)
  f___     # D natural (slur)
end

Instance Attribute Summary collapse

Attributes inherited from Event

#container, #parent

Instance Method Summary collapse

Methods inherited from Event

#detach_from_parent, #is_event_of?, #on_contained

Constructor Details

#initialize(pitch, duration) ⇒ Note

:call-seq:

new(pitch, duration) -> Alda::Note

The underlines in duration will be converted to tildes “~”. Exclamation mark and question mark in duration will be interpreted as accidentals in #pitch.

The number of underlines at the end of duration means: neither natural nor slur if 0, natural if 1, slur if 2, both natural and slur if 3.



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# File 'lib/alda-rb/event.rb', line 510

def initialize pitch, duration
	super()
	@pitch = pitch.to_s
	@duration = duration.to_s.tr ?_, ?~
	case @duration[-1]
	when ?! # sharp
		@pitch.concat ?+
		@duration[-1] = ''
	when ?? # flat
		@pitch.concat ?-
		@duration[-1] = ''
	end
	waves = /(?<str>~+)\z/ =~ @duration ? str.size : return
	@duration[@duration.length - waves..] = ''
	if waves >= 2
		waves -= 2
		@duration.concat ?~
	end
	@pitch.concat ?_ * waves
end

Instance Attribute Details

#duration ⇒ Object

The string representing the duration.

It ends with a tilde “~” if the note slurs.



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# File 'lib/alda-rb/event.rb', line 495

def duration
  @duration
end

#pitch ⇒ Object

The string representing the pitch



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# File 'lib/alda-rb/event.rb', line 489

def pitch
  @pitch
end

Instance Method Details

#+@ ⇒ Object

:call-seq:

+note -> note

Append a sharp sign after #pitch.

Alda::Score.new { piano_; +c }.play
# (plays a C sharp note)



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# File 'lib/alda-rb/event.rb', line 539

def +@
	@pitch.concat ?+
	self
end

#-@ ⇒ Object

:call-seq:

-note -> note

Append a flat sign after #pitch.

Alda::Score.new { piano_; -d }.play
# (plays a D flat note)



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# File 'lib/alda-rb/event.rb', line 552

def -@
	@pitch.concat ?-
	self
end

#==(other) ⇒ Object

:call-seq:

note == other -> true or false

Overrides Alda::Event#==. Returns true if other is an Alda::Note and has the same #pitch and #duration as note (using ==).



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# File 'lib/alda-rb/event.rb', line 588

def == other
	super || other.is_a?(Alda::Note) && @pitch == other.pitch && @duration == other.duration
end

#to_alda_code ⇒ Object

:call-seq:

to_alda_code() -> String

Overrides Alda::Event#to_alda_code.



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# File 'lib/alda-rb/event.rb', line 575

def to_alda_code
	result = @pitch + @duration
	result.concat ?*, @count.to_alda_code if @count
	result
end

#~ ⇒ Object

:call-seq:

~note -> note

Append a natural sign after #pitch.

Alda::Score.new { piano_; key_sig 'f+'; ~f }.play
# (plays an F note)



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# File 'lib/alda-rb/event.rb', line 565

def ~
	@pitch.concat ?_
	self
end