pytoolz/toolz — pull request #122 by mrocklin (2014-01-07 00:38:33+00:00)
Title: Add new `side_effects` function

Large scale feedback on this would be appreciated. I suspect that there is probably a better way to accomplish this.

In general the goal is to provide a mechanism to support side effects. I suspect this is the watered down version of the core idea behind monads.

Mostly I suspect this to be used with debugging, e.g.

```Python
seq = side_effects(print, seq) # hey look, Py3's print-is-a-function is a nice idea
result = do_work_on(seq)
```