This adds __hash__ to CsvFrac, and tweakes __eq__ to be more strict
about equality.
Previously CsvFrac only considered the relevant ratio for equality,
making hashing difficult:
- before: 1/2 == 2/4 => true
- after: 1/2 == 2/4 => false
But now that we have csv.py, with the explicit ratio function, it's
probably a good idea to be strict by default.
Note comparison is unchanged:
- 1/2 < 2/4 => false
- 1/2 > 2/3 => false
---
This popped up during debugging, and would be useful to have around.
Note CsvInt/CsvFloat already implicitly define __hash__ through
namedtuple's implicit __eq__ and friends. But this is disabled in
CsvFrac due to the explicit __eq__.
Which is good because otherwise it would've been wrong with the ratio
comparison!
Christopher Haster
73e06612bf