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41 lines
1.6 KiB
41 lines
1.6 KiB
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
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<pkgmetadata>
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<maintainer type="project">
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<email>haskell@gentoo.org</email>
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<name>Gentoo Haskell</name>
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</maintainer>
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<use>
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<flag name="hashable">
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Enisable the use of the `hashable` package. Disabling this may be useful
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for accelerating builds in sandboxes for expert users.
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Note: `-hashable` implies `-unordered-containers`, as we are necessarily
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not able to supply those instances as well.
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</flag>
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<flag name="containers">
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Enable the use of the `containers` package. Disabling this may be useful
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for accelerating builds in sandboxes for expert users.
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</flag>
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<flag name="unordered-containers">
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Enable the use of the `unordered-containers` package. Disabling this may
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be useful for accelerating builds in sandboxes for expert users.
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</flag>
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</use>
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<longdescription>
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Haskellers are usually familiar with monoids and semigroups. A monoid has an appending operation `<>` (or `mappend`),
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and an identity element, `mempty`. A semigroup has an appending `<>` operation, but does not require a `mempty` element.
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A Semiring has two appending operations, `plus` and `times`, and two respective identity elements, `zero` and `one`.
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More formally, a Semiring R is a set equipped with two binary relations `+` and `*`, such that:
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(R,+) is a commutative monoid with identity element 0,
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(R,*) is a monoid with identity element 1,
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(*) left and right distributes over addition, and
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multiplication by '0' annihilates R.
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</longdescription>
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</pkgmetadata>
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