On 03/17/2013 07:08 AM, C K Kashyap wrote:

I am working on an automation that periodically fetches bug data from
our bug tracking system and creates static HTML reports. Things worked
fine when the bugs were in the order of 200 or so. Now I am trying to
run it against 3000 bugs and suddenly I see things like - too  many open
handles, out of memory etc ...

Here's the code snippet - http://hpaste.org/84197

It's a small snippet and I've put in the comments stating how I run into
"out of file handles" or simply file not getting read due to lazy IO.

I realize that putting ($!) using a trial/error approach is going to be
futile. I'd appreciate some pointers into the tools I could use to get
some idea of which expressions are building up huge thunks.

You problem is in

let bug = ($!) fileContents2Bug str

($!) evaluate only WHNF and you need NF. Above just evaluate to first char in a file, not to all content. To fully evaluate 'str' you need something like

let bug = Control.DeepSeq.rnf str `seq` fileContents2Bug str

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