[erlang-questions] What makes erlang software complex

Andrew Stone <>
Sat Nov 8 00:25:27 CET 2008

mustn't feed trolls. trying so hard...

----- Original Message ----
From: Taavi Talvik <>
To: Sten Kvamme <>
Sent: Friday, November 7, 2008 5:53:59 PM
Subject: Re: [erlang-questions] What makes erlang software complex

On Nov 7, 2008, at 11:31 PM, Sten Kvamme wrote:

> In imperative programming there is Cyclomatic complexity and N-path
> complexity. What makes an erlang program complex?
> Thanks,
> Sten Kvamme

Personally I very much liked Joe Armstrong definition of "clean" and  
in his thesis http://www.erlang.org/download/armstrong_thesis_2003.pdf
section 8.3 page 171-174.

Clean functions are easy - for certain set of input, certain set of  
is produced. Probably both cyclomatic and n-path complexity can be  
to them.

Dirty functions either produce side effects or depend on side effects.
And their complexity is unknown, probably somewhere near infinity.

disclaimer - I don't have formal theoretical background to discuss  

best regards,

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