53 lines
1.1 KiB
Python
53 lines
1.1 KiB
Python
from _ import (
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T1,
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T2,
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Coco,
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Cocontra,
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Contraco,
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Contracontra,
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Contravariant,
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Covariant,
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Invariant,
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Unused,
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)
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unused: Unused = object()
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covariant: Covariant = object()
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contravariant: Contravariant = object()
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invariant: Invariant = object()
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coco: Coco = object()
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cocontra: Cocontra = object()
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contraco: Contraco = object()
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contracontra: Contracontra = object()
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t1: T1 = object()
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t2: T2 = object()
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# Dummy print to prudce judgements for the expressions
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print(
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unused,
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covariant,
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contravariant,
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invariant,
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coco,
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cocontra,
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contraco,
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contracontra,
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t1,
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t2,
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)
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cov1: Covariant[float] = object()
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cov2: Covariant[int] = object()
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cov1 = cov2 # Ok because int <: float => Covariant[int] <: Covariant[float]
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cov2 = cov1 # Invalid
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contra1: Contravariant[float] = object()
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contra2: Contravariant[int] = object()
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contra1 = contra2 # Invalid
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contra2 = contra1 # Ok because int <: float => Covariant[float] <: Covariant[int]
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inv1: Invariant[float] = object()
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inv2: Invariant[int] = object()
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inv1 = inv2 # Invalid
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inv2 = inv1 # Invalid
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