<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">To explain that further as to why it's not a bug...<div><br></div><div>GHCi's job is to run the code you enter. You asked it to show a value, so it executed the show function (correctly). The default implementation called showPrec, which invoked show, etc.</div><div><br></div><div>There may well be a missing feature here (to check of you implement nothing other than the defaults which are very likely to loop), but not a bug.</div><div><br></div><div>Bob</div><div><br><div><div>On 16 Nov 2010, at 11:44, Ozgur Akgun wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Unfortunately, yes.<br><br><div class="gmail_quote">On 16 November 2010 11:39, Russ Abbott <span dir="ltr"><<a href="mailto:russ.abbott@gmail.com">russ.abbott@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div dir="ltr"><font color="#003333"><font size="2"><font face="trebuchet ms,sans-serif">I'm not sure what you are saying here. Are you saying that it's not a bug that GHCi went into a coma when I file was loaded and a prompt entered?<br clear="all">
</font></font></font><div dir="ltr"><font><font face="'trebuchet ms', sans-serif"><i><font color="#003333"><br>-- Russ</font></i></font></font></div><div><div></div><div class="h5"><div dir="ltr"><font><i></i></font><font color="#003333" face="'trebuchet ms', sans-serif"><i><br>
</i></font><div><font><font face="'trebuchet ms', sans-serif"><i><font color="#003333"></font></i></font><br></font></div></div>
<br><br><div class="gmail_quote">On Tue, Nov 16, 2010 at 3:34 AM, Ozgur Akgun <span dir="ltr"><<a href="mailto:ozgurakgun@gmail.com" target="_blank">ozgurakgun@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><br><div class="gmail_quote">On 16 November 2010 05:12, Russ Abbott <span dir="ltr"><<a href="mailto:russ.abbott@gmail.com" target="_blank">russ.abbott@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<font color="#003333"><font size="2"><font face="trebuchet ms,sans-serif">I know the code isn't correct. My point is that the compiler didn't complain when the code was loaded, and the interpreter died when it was executed. That shouldn't happen.<br clear="all">
</font></font></font><div dir="ltr"><font><font face="'trebuchet ms', sans-serif"><i><font color="#003333"><br>-- Russ</font></i></font></font></div><div><div dir="ltr"></div></div></blockquote></div><div>
<br></div></div><div>It would be <i>cool</i> for GHC to make an analysis about the instance methods of a type class, and their default implementations to find the minimal subset of methods you have to implement to get a valid (for some definition of valid) instance declaration. But it doesn't do such a thing. And it is not an easy task.</div>
<div><br></div><div>GHC only warns you if you do not implement a method which doesn't have a default implementation. In your example, this is not the case.</div><div><br></div><div>Best,</div><div><br></div><div>-- </div>
Ozgur Akgun<font color="#888888"><br>
</font></blockquote></div><br></div></div></div>
</blockquote></div><br><br clear="all"><br>-- <br>Ozgur Akgun<br>
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