30 lines
1.1 KiB
Python
30 lines
1.1 KiB
Python
"""The [preserves.fold][] module exports various utilities for traversing compound `Value`s."""
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from .values import ImmutableDict, dict_kvs, Embedded, Record
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def map_embeddeds(f, v):
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"""Returns an [equivalent][preserves.compare.eq] copy of `v`, except where each contained
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[Embedded][preserves.values.Embedded] value is replaced by `f` applied to the Embedded's
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`embeddedValue` attribute.
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```python
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>>> map_embeddeds(lambda w: Embedded(f'w={w}'), ['a', Embedded(123), {'z': 6.0}])
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('a', #:'w=123', {'z': 6.0})
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```
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"""
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def walk(v):
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if isinstance(v, Embedded):
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return f(v.embeddedValue)
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elif isinstance(v, (list, tuple)):
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return tuple(walk(w) for w in v)
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elif isinstance(v, (set, frozenset)):
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return frozenset(walk(w) for w in v)
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elif isinstance(v, dict):
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return ImmutableDict.from_kvs(walk(w) for w in dict_kvs(v))
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elif isinstance(v, Record):
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return Record(walk(v.key), walk(v.fields))
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else:
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return v
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return walk(v)
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