https://wiki.haskell.org/index.php?title=Performance/Data_types&feed=atom&action=history
Performance/Data types - Revision history
2024-03-19T03:32:23Z
Revision history for this page on the wiki
MediaWiki 1.35.5
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=65513&oldid=prev
Ysangkok: fix link to UNPACK pragma
2023-02-04T16:41:46Z
<p>fix link to UNPACK pragma</p>
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 16:41, 4 February 2023</td>
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<td colspan="2" class="diff-lineno">Line 64:</td>
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<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>For more information, see [https://downloads.haskell.org/<del class="diffchange diffchange-inline">~</del>ghc/<del class="diffchange diffchange-inline">latest</del>/docs<del class="diffchange diffchange-inline">/html</del>/users_guide/<del class="diffchange diffchange-inline">glasgow_exts</del>.html#unpack-pragma The UNPACK pragma] in GHC's User Guide.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>For more information, see [https://downloads.haskell.org/ghc/<ins class="diffchange diffchange-inline">9.4.4</ins>/docs/users_guide/<ins class="diffchange diffchange-inline">exts/pragmas</ins>.html#unpack-pragma The UNPACK pragma] in GHC's User Guide.</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
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Ysangkok
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=61076&oldid=prev
Flupp: updated “The UNPACK pragma” link
2016-08-31T11:30:12Z
<p>updated “The UNPACK pragma” link</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<col class="diff-marker" />
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:30, 31 August 2016</td>
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<td colspan="2" class="diff-lineno">Line 64:</td>
<td colspan="2" class="diff-lineno">Line 64:</td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>For more information, see [<del class="diffchange diffchange-inline">http</del>://<del class="diffchange diffchange-inline">www</del>.haskell.org/ghc<del class="diffchange diffchange-inline">/docs</del>/latest/html/users_guide/<del class="diffchange diffchange-inline">pragmas</del>.html#unpack-pragma The UNPACK pragma] in GHC's User Guide.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>For more information, see [<ins class="diffchange diffchange-inline">https</ins>://<ins class="diffchange diffchange-inline">downloads</ins>.haskell.org/<ins class="diffchange diffchange-inline">~</ins>ghc/latest<ins class="diffchange diffchange-inline">/docs</ins>/html/users_guide/<ins class="diffchange diffchange-inline">glasgow_exts</ins>.html#unpack-pragma The UNPACK pragma] in GHC's User Guide.</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
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Flupp
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=60999&oldid=prev
Axman6: Add note about UnpackedSumTypes
2016-08-10T08:07:36Z
<p>Add note about UnpackedSumTypes</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 08:07, 10 August 2016</td>
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<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Enumerations don't count as single-constructor types as far as GHC is concerned, so they don't benefit from unpacking when used as strict constructor fields, or strict function arguments. This is a deficiency in GHC, but it can be worked around.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Enumerations don't count as single-constructor types as far as GHC is concerned, so they don't benefit from unpacking when used as strict constructor fields, or strict function arguments. This is a deficiency in GHC, but it can be worked around<ins class="diffchange diffchange-inline"> - These restrictions are being worked on in https://ghc.haskell.org/trac/ghc/wiki/UnpackedSumTypes which will allow sum-types including "enums" to be unpacked and remove the need for the following solution once released</ins>.</div></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One way to work around it is to declare your enumeration as an int-like type, instead of the usual enumeration type. For example, if you have</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One way to work around it is to declare your enumeration as an int-like type, instead of the usual enumeration type. For example, if you have</div></td>
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Axman6
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=21884&oldid=prev
Coffee2theorems: typo
2008-07-21T22:06:24Z
<p>typo</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 22:06, 21 July 2008</td>
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<td colspan="2" class="diff-lineno">Line 68:</td>
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<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=== Enumerations ===</div></td>
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<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Enumerations don't count as single-constructor types as far as GHC is concerned, so they don't benefit from unpacking when used as strict constructor fields, or strict function arguments. This is a <del class="diffchange diffchange-inline">defficiency</del> in GHC, but it can be worked around.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Enumerations don't count as single-constructor types as far as GHC is concerned, so they don't benefit from unpacking when used as strict constructor fields, or strict function arguments. This is a <ins class="diffchange diffchange-inline">deficiency</ins> in GHC, but it can be worked around.</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One way to work around it is to declare your enumeration as an int-like type, instead of the usual enumeration type. For example, if you have</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>One way to work around it is to declare your enumeration as an int-like type, instead of the usual enumeration type. For example, if you have</div></td>
</tr>
</table>
Coffee2theorems
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=20806&oldid=prev
Dbueno: Remove vague language about newtypes, since dons confirms it is unnecessary
2008-05-08T01:47:14Z
<p>Remove vague language about newtypes, since dons confirms it is unnecessary</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 01:47, 8 May 2008</td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Newtypes ==</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Newtypes ==</div></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
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<tr>
<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>If your datatype has a single constructor with a single field, use a <tt>newtype</tt> declaration instead of a <tt>data</tt> declaration. The <tt>newtype</tt> constructor will be optimised away<del class="diffchange diffchange-inline"> in most cases</del>.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>If your datatype has a single constructor with a single field, use a <tt>newtype</tt> declaration instead of a <tt>data</tt> declaration. The <tt>newtype</tt> constructor will be optimised away.</div></td>
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<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>In fact, <tt>newtypes</tt><del class="diffchange diffchange-inline"> usually</del> cost nothing, so they can be used to document your code for free.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>In fact, <tt>newtypes</tt> cost nothing, so they can be used to document your code for free.</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Strict fields ==</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Strict fields ==</div></td>
</tr>
</table>
Dbueno
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=13724&oldid=prev
Fpotargent: Corrected typo
2007-06-25T07:36:27Z
<p>Corrected typo</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 07:36, 25 June 2007</td>
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<td colspan="2" class="diff-lineno">Line 60:</td>
<td colspan="2" class="diff-lineno">Line 60:</td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> data T = T Int#</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div> data T = T Int#</div></td>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>where Int# is the unboxed integer type. You don't have to mention Int# in your program - just putting the {-# <del class="diffchange diffchange-inline">UNAPCK</del> #-} directive on the field is enough to tell GHC that this is the representation you want, and GHC will eliminate the boxing. The same result can be achieved without explicit UNPACK pragmas by using the ''-funbox-strict-fields'' optimisation.</div></td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>where Int# is the unboxed integer type. You don't have to mention Int# in your program - just putting the {-# <ins class="diffchange diffchange-inline">UNPACK</ins> #-} directive on the field is enough to tell GHC that this is the representation you want, and GHC will eliminate the boxing. The same result can be achieved without explicit UNPACK pragmas by using the ''-funbox-strict-fields'' optimisation.</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Note that {-# UNPACK #-} isn't the default, for the reason that it isn't always a good idea. If there is a pattern match on a constructor with an unpacked field, and the value of that field is passed to a non-strict function, GHC has to re-box the value before passing it on. If this re-boxing is common, then unpacking can be slower than not unpacking. The effect can be more acute if the type being unpacked has a lot of components (eg. a 17-tuple).</div></td>
</tr>
</table>
Fpotargent
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=10260&oldid=prev
Quale: +cat
2007-01-13T11:26:36Z
<p>+cat</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 11:26, 13 January 2007</td>
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<td colspan="2" class="diff-lineno">Line 1:</td>
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<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{Performance infobox}}</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>{{Performance infobox}}</div></td>
</tr>
<tr>
<td colspan="2" class="diff-empty"> </td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Performance|Data types]]</div></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Newtypes ==</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>== Newtypes ==</div></td>
</tr>
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<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
</table>
Quale
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=2927&oldid=prev
Ashley Y: rv spam
2006-03-12T07:55:57Z
<p>rv spam</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<col class="diff-content" />
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 07:55, 12 March 2006</td>
</tr><tr>
<td colspan="2" class="diff-lineno">Line 89:</td>
<td colspan="2" class="diff-lineno">Line 89:</td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
</tr>
<tr>
<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> <div id="ghsfg5dfhsdfhd" style="overflow:auto;height:3px;">[http://www.zorpia.com/replicawatch2 replica watch] </div></div></td>
<td colspan="2" class="diff-empty"> </td>
</tr>
</table>
Ashley Y
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=2912&oldid=prev
Awjvff at 19:29, 11 March 2006
2006-03-11T19:29:09Z
<p></p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
<col class="diff-marker" />
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<col class="diff-marker" />
<col class="diff-content" />
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 19:29, 11 March 2006</td>
</tr><tr>
<td colspan="2" class="diff-lineno">Line 89:</td>
<td colspan="2" class="diff-lineno">Line 89:</td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
</tr>
<tr>
<td colspan="2" class="diff-empty"> </td>
<td class="diff-marker">+</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div> <div id="ghsfg5dfhsdfhd" style="overflow:auto;height:3px;">[http://www.zorpia.com/replicawatch2 replica watch] </div></div></td>
</tr>
</table>
Awjvff
https://wiki.haskell.org/index.php?title=Performance/Data_types&diff=2904&oldid=prev
Ashley Y: rv spammer
2006-03-10T23:04:06Z
<p>rv spammer</p>
<table class="diff diff-contentalign-left diff-editfont-monospace" data-mw="interface">
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 23:04, 10 March 2006</td>
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<td colspan="2" class="diff-lineno">Line 89:</td>
<td colspan="2" class="diff-lineno">Line 89:</td>
</tr>
<tr>
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<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td>
</tr>
<tr>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
<td class="diff-marker"> </td>
<td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Also, you have to hide the representation of Color appropriately so that invalid values can't be constructed (<tt>Color 99</tt>).</div></td>
</tr>
<tr>
<td class="diff-marker">−</td>
<td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div> <div id="ghsfg5dfhsdfhd" style="overflow:auto;height:1px;">[http://www.zorpia.com/replicawatch2 replica watch] </div></div></td>
<td colspan="2" class="diff-empty"> </td>
</tr>
</table>
Ashley Y