.. Ross Patterson's Blog imported post, created by `$ ./bin/rfc822-to-post` on Mar 15, 2021.

.. meta::
   :description: Some complexity belongs in your editor/IDE
   :keywords: Plone, Zope

.. post:: Nov 25, 2008
   :tags: Plone, Zope
   :author: Ross Patterson
   :redirect:  @@redirect-to-uuid/2b212e3d15629a14bbf70a2df11ef924

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Balancing DRY and Readability
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    Some complexity belongs in your editor/IDE

I was writing a combination of setuphandlers and functional test
fixtures recently when I found myself doing something noteworthy.  I
was converting both apparatus from a set of loops over content type
names and prefixes to a few utility functions with lots of repetitious
calls.  Why was I violating DRY?  Because I couldn't make sense of
things!  Oh yeah, DRY should never compromise readability.  :)

It's definitely possible to take DRY too far leading to such
slap-your-forehead moments as this.  I think that setup code, whether
for install or a test fixture, is particularly prone to this.  I've
both written a lot of setup code and read a lot of it in the wild
where a bunch of complex structure is introduced in the name of DRY.

What I ended up doing was writing a small number of utility functions
whose call signatures were intuitive and readable.  Then I used a
bunch of complex "M-x query-replace-regexp" commands in Emacs to convert the
complicated structure into a simple, readable, flat, but nonetheless
very repetitious function calls.  Later when I needed additional set
up, I used the same complex editor command to accomplish the task.  

It occurred to me that what I was doing was taking unreadable
complexity out of code where I, let alone someone else, couldn't
remember or read what was going on, and i was moving it into my tools.
My tools I use every day so I remember how to manage the complexity
and I'm not condemning others to learn the complexity when I put it
there.  I think this makes a simple guideline for balancing DRY with
readability.  Some complexity belongs in your tool usage, not in the
code.

.. update:: Nov 25, 2008

   Imported from Plone on Mar 15, 2021.  The date for this update is the last
   modified date in Plone.