Function parseKeyName

parseKeyName(text: string, opts?: NoteNameOptions): KeyName
Parse a key name such as 'C major', 'gis moll' or '嬰ト短調'.

The name is a tonic followed by a mode word, in any of the supported notation systems; German also accepts its hyphenated form ('gis-Moll'). Without a system the name is attributed by detectNoteNameSystem, so a mode word is itself enough to pick one: 'B dur' is B flat major while 'B major' is B major.

German carries the mode twice, in the word and in the case of the tonic (C dur, c moll). When the two disagree the word wins — 'C moll' is C minor — because the word is what the writer said and the case only what they typed. A German name with no mode word is decided by its case alone ('gis' is G sharp minor, 'Gis' G sharp major); a bare tonic in any other system names a major key.
Parameters
- text: string
  The key name.
- Optionalopts: NoteNameOptions
  system reads the name in that notation system instead of detecting it.
Returns KeyName
The spelled tonic and the mode.
Throws
If the text is not a key name in the given (or detected) system, if it mixes two systems, or if the tonic carries an octave. Use tryParseKeyName where failure is ordinary, such as a key field read on every keystroke.
Example
```
import { formatNote, parseKeyName } from '@libraz/libcantus';
const key = parseKeyName('gis moll');
formatNote(key.tonic); // 'G#'
key.mode; // 'minor'
```
- Defined in src/core/pitch/index.ts:310