<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none"><!--P{margin-top:0;margin-bottom:0;} .ms-cui-menu {background-color:#ffffff;border:1px rgb(171, 171, 171) solid;font-family:'Segoe UI WPC', 'Segoe UI', Tahoma, 'Microsoft Sans Serif', Verdana, sans-serif;font-size:11pt;color:rgb(51, 51, 51);} .ms-cui-menusection-title {display:none;} .ms-cui-ctl {vertical-align:text-top;text-decoration:none;color:rgb(51, 51, 51);} .ms-cui-ctl-on {background-color:rgb(229, 235, 236);opacity: 0.8;} .ms-cui-img-cont-float {display:inline-block;margin-top:2px} .ms-cui-smenu-inner {padding-top:0px;} .ms-owa-paste-option-icon {margin: 2px 4px 0px 4px;vertical-align:sub;padding-bottom: 2px;display:inline-block;} .ms-rtePasteFlyout-option:hover {background-color:rgb(229, 235, 236) !important;opacity:1 !important;} .ms-rtePasteFlyout-option {padding:8px 4px 8px 4px;outline:none;} .ms-cui-menusection {float:left; width:85px;height:24px;overflow:hidden}.wf {speak:none; font-weight:normal; font-variant:normal; text-transform:none; -webkit-font-smoothing:antialiased; vertical-align:middle; display:inline-block;}.wf-family-owa {font-family:'o365Icons'}@font-face { font-family:'o365IconsIE8'; src:url('prem/15.0.913.22/resources/styles/office365icons.ie8.eot?#iefix') format('embedded-opentype'), url('prem/15.0.913.22/resources/styles/office365icons.ie8.woff') format('woff'), url('prem/15.0.913.22/resources/styles/office365icons.ie8.ttf') format('truetype'); font-weight:normal; font-style:normal;}@font-face { font-family:'o365IconsMouse'; src:url('prem/15.0.913.22/resources/styles/office365icons.mouse.eot?#iefix') format('embedded-opentype'), url('prem/15.0.913.22/resources/styles/office365icons.mouse.woff') format('woff'), url('prem/15.0.913.22/resources/styles/office365icons.mouse.ttf') format('truetype'); font-weight:normal; font-style:normal;}.wf-family-owa {font-family:'o365IconsMouse'}.ie8 .wf-family-owa {font-family:'o365IconsIE8'}.ie8 .wf-owa-play-large:before {content:'\e254';}.notIE8 .wf-owa-play-large:before {content:'\e054';}.ie8 .wf-owa-play-large {color:#FFFFFF/*$WFWhiteColor*/;}.notIE8 .wf-owa-play-large {border-color:#FFFFFF/*$WFWhiteColor*/; width:1.4em; height:1.4em; border-width:.1em; border-style:solid; border-radius:.8em; text-align:center; box-sizing:border-box; -moz-box-sizing:border-box; padding:0.1em; color:#FFFFFF/*$WFWhiteColor*/;}.ie8 .wf-size-play-large {width:40px; height:40px; font-size:30px}.notIE8 .wf-size-play-large {width:40px; height:40px; font-size:30px}--></style>
</head>
<body dir="ltr">
<div style="font-size:12pt;color:#000000;background-color:#FFFFFF;font-family:Calibri,Arial,Helvetica,sans-serif;">
<p>The way I read Alan's earlier mail is precisely that; auto-generated Show does what he wants (show the entire AST), whereas Outputable hides too much information. I very much understand his frustration with having to manually figure out what constructors
and datatypes go where in a compiled program. Alan's point was the *absence* of auto derived Show instances and, in the case of SrcSpan, too much verbosity (rather than wanting stuff to be incomplete).<br>
</p>
<p><br>
</p>
<p>Allowing some bespoke stuff to reduce the noise of something like record field names for SrcSpan makes even more sense in this context. Similarly, this is why Alan & I want everything to have Data instances, so you can (amongst many other nice things) selectively
print parts of the AST.<br>
</p>
<p><br>
</p>
<p>Ph.<br>
</p>
<p><br>
</p>
<p><br>
</p>
<p><br>
</p>
<div style="color: rgb(40, 40, 40);">
<hr tabindex="-1" style="display:inline-block; width:98%">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Alan & Kim Zimmerman <alan.zimm@gmail.com><br>
<b>Sent:</b> 06 October 2014 15:15<br>
<b>To:</b> Mateusz Kowalczyk<br>
<b>Cc:</b> ghc-devs@haskell.org<br>
<b>Subject:</b> Re: Show instance for SrcSpan</font>
<div> </div>
</div>
<div>
<div dir="ltr">True, but if you are using GHC generated stuff via the GHC API you sometimes do not want to have to implement Outputable for all your app types, when you can auto derive Show which mostly does what you need.<br>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">On Mon, Oct 6, 2014 at 3:11 PM, Mateusz Kowalczyk <span dir="ltr">
<<a href="mailto:fuuzetsu@fuuzetsu.co.uk" target="_blank">fuuzetsu@fuuzetsu.co.uk</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex; border-left:1px #ccc solid; padding-left:1ex">
<div class="HOEnZb">
<div class="h5">On 10/06/2014 01:59 PM, Alan & Kim Zimmerman wrote:<br>
> Is there any reason I can't put in a diff request to replace the derived<br>
> Show instance for SrcSpan with a handcrafted one that does not exhausively<br>
> list the constructors, making it more readable?<br>
><br>
> Alan<br>
><br>
<br>
</div>
</div>
Why? If you're looking for pretty output then you should be changing<br>
Outputable.<br>
<span class="HOEnZb"><font color="#888888"><br>
<br>
--<br>
Mateusz K.<br>
_______________________________________________<br>
ghc-devs mailing list<br>
<a href="mailto:ghc-devs@haskell.org">ghc-devs@haskell.org</a><br>
<a href="http://www.haskell.org/mailman/listinfo/ghc-devs" target="_blank">http://www.haskell.org/mailman/listinfo/ghc-devs</a><br>
</font></span></blockquote>
</div>
<br>
</div>
</div>
</div>
</div>
</body>
</html>