Class: HeadMusic::Rudiment::Quality

Inherits:
Base
  • Object
show all
Defined in:
lib/head_music/rudiment/quality.rb

Overview

A quality is a categorization of an interval.

Constant Summary collapse

SHORTHAND = 
{
  perfect: "P",
  major: "M",
  minor: "m",
  diminished: "d",
  augmented: "A",
  doubly_diminished: "dd",
  doubly_augmented: "AA"
}.freeze
NAMES = 
SHORTHAND.keys
PERFECT_INTERVAL_MODIFICATION = 
{
  -2 => :doubly_diminished,
  -1 => :diminished,
  0 => :perfect,
  1 => :augmented,
  2 => :doubly_augmented
}.freeze
MAJOR_INTERVAL_MODIFICATION = 
{
  -2 => :diminished,
  -1 => :minor,
  0 => :major,
  1 => :augmented,
  2 => :doubly_augmented
}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name) ⇒ Quality 



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# File 'lib/head_music/rudiment/quality.rb', line 52

def initialize(name)
  @name = name
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/head_music/rudiment/quality.rb', line 48

def name
  @name
end

Class Method Details

.from(starting_quality, delta) ⇒ Object 



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# File 'lib/head_music/rudiment/quality.rb', line 39

def self.from(starting_quality, delta)
  case starting_quality
  when :perfect
    PERFECT_INTERVAL_MODIFICATION[delta].to_s.gsub(/_+/, " ")
  when :major
    MAJOR_INTERVAL_MODIFICATION[delta].to_s.gsub(/_+/, " ")
  end
end

.get(identifier) ⇒ Object 



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# File 'lib/head_music/rudiment/quality.rb', line 33

def self.get(identifier)
  @qualities ||= {}
  identifier = identifier.to_s.to_sym
  @qualities[identifier] ||= new(identifier) if NAMES.include?(identifier)
end

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/head_music/rudiment/quality.rb', line 56

def ==(other)
  to_s == other.to_s
end

#article ⇒ Object 



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# File 'lib/head_music/rudiment/quality.rb', line 64

def article
  %w[a e i o u h].include?(name.to_s.first) ? "an" : "a"
end

#shorthand ⇒ Object 



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# File 'lib/head_music/rudiment/quality.rb', line 60

def shorthand
  SHORTHAND[name]
end