Python-based monads essay (Re: Assignment versus binding)

[Ben Finney]

Gregory Ewing <greg.ewing at canterbury.ac.nz> writes:

> Here's the first part of the essay I said I'd write about
> monads:

Thank you for tackling this.

> http://www.cosc.canterbury.ac.nz/greg.ewing/essays/monads/DemystifyingMonads.html

You appreciate an important feature of this:

    Often it is presented in a very abstract and mathematical way, which
    tends to have an eye-glazing effect on people who aren't hard-core
    mathematicians. This is an attempt to convey the basic ideas behind
    monads to someone who is a programmer rather than a mathematician.

One important lack that I often see in essays written by mathematicians
about programming, is the tendency to use opaque single-character
symbols., such as might be easy to write in chalk on a blackboard.

In a programming language, though, we do not have the constraint of
writing them with chalk on a blackboard. Symbols can be given
*descriptive names*, that communicate the semantic meaning of the
symbol.

Can you re-write the code examples, for example::

    def add(x, f, s):
      s.add(x)
      return f(s)

so that they are PEP 8 conformant? That means (in addition to 4-column
indentation at each level) that you should *choose descriptive
names* and use them consistently, to help the reader understand the
code.

-- 
 \        “Telling pious lies to trusting children is a form of abuse, |
  `\                    plain and simple.” —Daniel Dennett, 2010-01-12 |
_o__)                                                                  |
Ben Finney