Make Quality a recursive type

music-suite / music-pitch

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http://music-suite.github.io

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Closed hanshoglund closed 8 years ago

hanshoglund commented 9 years ago

data Quality
  = Major
  | Minor
  | Perfect
  | Augment Quality
  | Diminish Quality

Easier to define normalization.
Prohibits semantic bugs such as the Augmentable Quality instance (bad because it allows augment (Diminished 1): should be replaced by an internal function whenever it is used internally).

hanshoglund commented 8 years ago

Actually bad, this would lead to Augment Major /= Augment Perfect. Closing this.