You can comment out the definition of bad and add a new one:<br><span style="font-family: courier new,monospace;">bad = undefined</span><br>The
file should load properly. Functions that use "bad" will compile too,
but if they try to evaluate it an error will be raised.<br><br>(sorry, forgot to hit "reply to all" the first time)<br><br><div class="gmail_quote">On Thu, Apr 16, 2009 at 1:34 PM, aditya siram <span dir="ltr"><<a href="mailto:aditya.siram@gmail.com">aditya.siram@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Hi all,<br>I'm curious as to how one would go about debugging the following program:<br>
<font size="1"><span style="font-family: courier new,monospace;"><br>hello :: String</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">hello = "Hello"</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">world :: String</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">world = "World"</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">number :: Int</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">number = 1</span><br style="font-family: courier new,monospace;"><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">helloWorld :: String</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">helloWorld = hello ++ " " ++ world</span><br style="font-family: courier new,monospace;"><br>-- This fails!<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">bad :: String</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;">bad = hello ++ number</span></font><br><br>Predictably once I load this program into ghci I get the following error:<br><font size="1"><span style="font-family: courier new,monospace;">[1 of 1] Compiling Main ( TestCode.hs, interpreted )</span><br style="font-family: courier new,monospace;">
<br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">TestCode.hs:14:15:</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> Couldn't match expected type `[Char]' against inferred type `Int'</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> In the second argument of `(++)', namely `number'</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;"> In the expression: hello ++ number</span><br style="font-family: courier new,monospace;">
<span style="font-family: courier new,monospace;"> In the definition of `bad': bad = hello ++ number</span><br style="font-family: courier new,monospace;"><span style="font-family: courier new,monospace;">Failed, modules loaded: none.</span><br style="font-family: courier new,monospace;">
</font><br>At this point what I want to do is to query the output type of the different functions like so:<br><font size="1"><span style="font-family: courier new,monospace;">> :t hello</span></font><br>but GHCI won't let me because the program hasn't been loaded. <br>
<br>I would then have to comment out 'bad', reload the program and query output types to my hearts content. This is fine for a small program, but when I have functions are downriver from 'bad', it gets extremely cumbersome. Is there a way to load a file such that functions that compile stay loaded in the interpreter even if something else fails?<br>
<br>Thanks ...<br>-deech<br>
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<br></blockquote></div><br>