feat: add options for behaviour when dividing by zero or calculating log zero #329
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extensions/functions_arithmetic.yaml
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| description: > | ||
| Divide x by y. In the case of integer division, partial values are truncated. | ||
| The `on_division_by_zero` option governs behaviour in cases where y is 0 and x is not 0. | ||
| The `on_domain_error` option governs behaviour for 0/0 and Inf/Inf etc. |
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Not sure if this is quite right?
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It looks fine to me, but cc @pitrou
ETA: actually, the order should probably be LIMIT, NAN, and then ERROR, because LIMIT makes the most sense. We should probably specify what LIMIT means, too (i.e. +/- infinity based on sign of numerator and signed zero denominator).
PS. I honestly can't tell if github actually added this comment when I first reviewed this because the UI was glitching all to hell, but it seems to be missing for me now, so... Please excuse me if this ends up being duplicated.
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That makes sense, updated now!
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extensions/functions_arithmetic.yaml
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| @@ -175,7 +175,10 @@ scalar_functions: | |||
| return: fp64 | |||
| - | |||
| name: "divide" | |||
| description: "Divide one value by another. Partial values are truncated." | |||
| description: > | |||
| Divide x by y. In the case of integer division, partial values are truncated. | |||
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Can we describe more precisely what "partial values are truncated" means? (truncated towards zero, or truncated towards minus infinity - i.e. floored?)
For example, what would be the result of 1 / -3?
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+1, we use "truncation" for rounding toward zero (in contrast with ceil for +infinity and floor for -infinity) but it bears repeating.
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I have not seen truncation defined before as anything other than "round towards zero", but adding a few extra words does no harm, so updated here.
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This PR adds options which allow specification of behaviour when dividing by 0 or when trying to calculate log of 0. See discussion on #302 for more detail.