forked from lix-project/lix
d0f2da214b
* Clarify the documentation of foldl': That the arguments are forced before application (?) of `op` is necessarily true. What is important to stress is that we force every application of `op`, even when the value turns out to be unused. * Move the example before the comment about strictness to make it less confusing: It is a general example and doesn't really showcase anything about foldl' strictness. * Add test cases which nail down aspects of foldl' strictness: * The initial accumulator value is not forced unconditionally. * Applications of op are forced. * The list elements are not forced unconditionally.
7 lines
271 B
Nix
7 lines
271 B
Nix
# Checks that the nul value for the accumulator is not forced unconditionally.
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# Some languages provide a foldl' that is strict in this argument, but Nix does not.
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builtins.foldl'
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(_: x: x)
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(throw "This is never forced")
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[ "but the results of applying op are" 42 ]
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