Write programs as if they were mathematical
essays, but with code instead of equations. This is
“literate programming”, an idea invented by
the famous computer scientist
Donald Knuth. The quote below is from
www.literateprogramming.com ,
apparently first published
by Knuth in “Literate Programming (1984)” in
Literate Programming, CSLI, 1992, page 99:

I believe that the time is ripe for
significantly better documentation of programs, and that
we can best achieve this by considering programs to be
works of literature. Hence, my title: “Literate Programming.”

Let us change our traditional attitude to the construction of
programs: Instead of imagining that our main task is to instruct
a computer what to do, let us concentrate rather on explaining to human
beings what we want a computer to do.

The practitioner of literate programming can be regarded as an
essayist, whose main concern is with exposition and excellence
of style. Such an author, with thesaurus in hand, chooses the
names of variables carefully and explains what each variable
means. He or she strives for a program that is comprehensible
because its concepts have been introduced in an order that is
best for human understanding, using a mixture of formal and
informal methods that reinforce each other.

With our model, there are at least three classes
of user who need explaining to. One is me, in six
months’ time after I’ve forgotten how my code worked.
The second is my colleague.
And the third is the economists and
others who will use the model.

This final class need a little extra help.
My networks can be seen as a kind of literate program where
the expository narrative is branched rather than linear, and the essayist
is writing around function definitions rather than
equations. Traditionally, economic models have been opaque,
their assumptions known only to the few who
implemented them. But with this kind of display, everyone is free
to peer inside.