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Path: utzoo!watmath!clyde!caip!topaz!gaynor
From: gaynor@topaz.RUTGERS.EDU (Silver)
Newsgroups: net.lang
Subject: Re: compound statements
Message-ID: <5303@topaz.RUTGERS.EDU>
Date: Wed, 9-Jul-86 01:06:36 EDT
Article-I.D.: topaz.5303
Posted: Wed Jul  9 01:06:36 1986
Date-Received: Wed, 9-Jul-86 06:46:46 EDT
References: <5281@topaz.RUTGERS.EDU> <2296@umcp-cs.UUCP>
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 55

[]

In article <2296@umcp-cs.UUCP>, mangoe@umcp-cs.UUCP (Charley Wingate) writes:

[clarification, not really there]
> Silver {...!topaz!gaynor} writes:
>
> > [flamage about languages requiring the body of (sub-)programs be
> > restricted to compound statements]
[clarifaction, not really there]
>
> In languages like Pascal, where there may be functions within
> functions, it is necessary to have some sort of "end-of-procedure"
> delimiter. 

Not true.

What gives rise to ambiguity is the null statement.  Consider a
language that allows null statements, and an arbitrary statement as a
(sub-)program body.  In the following, example, to which procedure
would the 'writestring' be bound?

== example.pseudo ==
# I consider the 'program' keyword to be unnecessary. #
procedure example (output - text)

  procedure this

    procedure that

# the code in question #
writestring (output, "What procedure calls this statement?")
====================

Recall how Pascal resolves 'else' clause ambiguities.  Simply bind it
to the nearest unclosed 'if-then' (not 'if-then-else') statement.
That convention is applicable here.  If the definition of the language
stated that a statement is bound to the nearest unclosed procedure,
then no ambiguity results.  The 'writestring' statement is bound to
'that', a null-statement to 'this' and 'test'.

If you need to verify this to yourself (I did, of course, because I'm
posting :-), write some sample test code and mentally parse it...

                         _   /|
                         \`o_O'
                           ( )   Aachk! Phft!   
                            U

Disclaimer: The opinions and/or information and/or code expressed
            here were generated by this characature, stolen from
            Dave Rasmussen, to which I have taken the liberty of
            adding ears.  So don't look to me for a disclaimer!

Silver  {...!topaz!gaynor}