🚀 go-pugleaf

dll@ut-emx.uucp (Don Loflin) writes:
>Basically, explicit statement delimitation is probably a good idea, but
>block delimitation should use whitespace.  In off-side rule languages,
>you do run into the problem of indenting yourself off the page.  You
>could avoid that, but still reap the benefits of the off-side rule by
>using it only for block delimitation.  I also suggest a modification
>to the rule such that the amout of white space in the first line of a
>block determines the amount that delimits.

By definition (Landin's) a syntactic entity governed by the off-side
rule extends up to a line less indented than its _first_token_. It
gets a little tiresome to see repeated suggestions that it should be
modified to do what it has always done. (There is a widespread _style_
in Miranda that starts off-side blocks without going to a new line.
It looks nice in typeset examples....)

Further, both Miranda and Haskell use the off-side rule for a very
limited number of syntactic constructs. Haskell comes quite close to
your block-only idea, but allows implicit ``statement'' delimiters by
returning to the indentation of the first line in the ``block''.
Miranda wants to use the off-side rule to separate the uses of "=" as
definition and equality, so it's a little weird. (Guess where the
three off-side blocks are in
	foo x y = 0, if e
	        = 1, otherwise
	          where e = x = y
.)

Lastly, occam is not a functional language, and it doesn't use
Landin's off-side rule. Criticism should go to comp.sys.transputer, if
anywhere.

--
Lars Mathiesen, DIKU, U of Copenhagen, Denmark      [uunet!]mcsun!diku!thorinn
Institute of Datalogy -- we're scientists, not engineers.      thorinn@diku.dk