OpenEuphoria

commabominations

• Posted by George Henry <ghenryca at hotmail.com> Jan 20, 2001
• 433 views

This came out in a recent personal message. Thought I'd air it to the list
as well.

In natural language, commas are used to separate items in a list. Fine and
dandy. In natural language we do not frequently modify lists that look like
this: { A, B, C } to look like this: { A, B, C, D } or this:
{ A, B }. Not as frequently as we do in programming, anyway.

Now suppose we did. We might be tempted, in order to avoid juggling commas,
to end all our lists with ", etc."

The point is this:

The way Euphoria and most other languages treat/use/handle commas leads to
syntactic abominations, such as I have seen in the latest win32lib, and (I
report unhappily) have even adopted myself:

<excerpt from win32lib_full.ew>
integer
     riCleanUp                -- the "clean up" routine
   , ri_getClientRect         -- routine_id for getClientRect()
   , riPause                  -- routine_id for Pause Key processing
   , riBreak                  -- routine_id for Break Key processing
</excerpt>

This should not happen, should not be necessary. Commas are not used that
way in natural language. It's ugly.

Okay, then what's a reasonable solution? I have actually seen a C compiler
that let you do this, in initializers: { A, B, C, } which is using the comma
more as a terminator than as a separator, or it is blurring the
terminator/separator distinction. Either way, I'd like to see something of
the sort allowed by Euphoria (or any language I use on a regular basis).

Pascal used the semicolon as a separator between statements, but did not
complain of "syntax error" if you used one just prior to an "end." Same
idea.

How about just a generic keyword "end" that means nothing, but lets you end
a list with ", end" - as in:

constant
  alpha=120,
  beta=26,
  gamma=1382,
end
integer
  riCleanUp,                -- the "clean up" routine
  ri_getClientRect,         -- routine_id for getClientRect()
  riPause,                  -- routine_id for Pause Key processing
  riBreak,                  -- routine_id for Break Key processing
end

so you can add to or subtract from the list without adding and deleting
commas, and without sticking the commas in front of the identifiers - thus
reducing readability (similarity to natural language)?

You don't have to break any existing code to implement this. ", end" would
be strictly optional at the end of a list of constants or variable names.
(I'd also like to see a trailing comma before the closing curly brace
tolerated in a sequence.)

This may seem a small thing, but "the devil's in the details," and that
little comma has horns and a tail, as far as I'm concerned.

What do y'all think?

George
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