Python is readable

Steve Howell showell30 at yahoo.com
Thu Mar 22 01:54:14 CET 2012


On Mar 21, 4:34 pm, Steven D'Aprano <steve
+comp.lang.pyt... at pearwood.info> wrote:
> On Wed, 21 Mar 2012 11:22:01 -0500, Evan Driscoll wrote:
> > On 01/-10/-28163 01:59 PM, Steve Howell wrote:
> >> Code shouldn't necessarily follow the example of English prose, but it
> >> seems that English has had some influence:
>
> >>   1  push(stack, item) # Push on the stack the item
> >>   2  push(item, stack) # Push the item on the stack
> >>   3  stack.push(item)  # On the stack, push the item
> >>   4  stack item push   # On the stack, take the item and push it
> >>   5  item stack push   # Take the item and on the stack, push the
> >>      former.
> >>   6  item push stack   # Take the item; push it on the stack.
>
> >> The first three ways are the most common ways of arranging the grammar
> >> in mainstream programming languages, and they are also the three most
> >> natural ways in English (no pronouns required).
>
> >> #1/2 are imperative.  #3 is OO.
>
> > In my opinion, people who make statements such as "#1/2 are imperative,
> > #3 is OO" are missing pretty much the entire point of what OO is.
>
> > OO is much more about semantics and the way code is structured. The
> > difference between #1/2 (especially #1, of course) and #3 is
> > surface-level syntax only.
>
> +1000
>
> I like to talk about "object oriented SYNTAX" (emphasis added) to
> distinguish the typical OO dotted syntax obj.attr (or obj->attr) from
> other syntax varieties. But this must be understood as mere convention.
> One could invent an OO language which used syntax "push(stack, item)" or
> even something exotic like "item!push~stack" and it would remain OO, only
> with unusual syntax.
>

Sorry if I caused confusion here.  When I labelled certain syntaxes as
"imperative" and certain syntaxes as "object-oriented," I never meant
to imply anything about the semantic layer.  (I think Evan misread my
post a bit, and then went a little overboard with his comment that
people like me "are missing the entire point of OO.")

Clearly, I get the fact that there can be multiple valid syntaxes to
express the same underlying operation, as evidenced by my presenting
six permutations of stack/push/item.

The discussion that I thought would be interesting is this--given six
seemingly arbitrary ways of expressing the same idea, how do you
decide?  My hypothesis is that we all have prior conditioning such
that the arrangement of words actually *does* matter.  And the
conditioning comes from multiple realms--we speak natural languages,
we have familiarity with arithmetic notation, and we have traditions
from programming itself.

The place where token arrangement resonates best with me is
arithmetic.  I can deal with all of the expressions on a semantic
level:

  5 + 3
  5 3 +
  + 5 3

On a purely theoretical level, the choice of syntax doesn't really
matter (it's just a convention), but the convention is so strong, it
matters on a readability level.  Even though I can grok prefix/
postfix, I feel uncomfortable in programming languages that don't have
"infix" sugar.  Imagine if Python didn't support infix sugar.  No
semantic change, right?  But it would still matter for some...







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