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From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: What does "a---b" mean?
Message-ID: <21602@mimsy.umd.edu>
Date: 3 Jan 90 08:30:28 GMT
References: <1303@mit-amt.MEDIA.MIT.EDU>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 28

In article <1303@mit-amt.MEDIA.MIT.EDU> adamk@mit-amt.MEDIA.MIT.EDU
(Adam Kao) writes:
>To summarize, my understanding is:
>
>1. The lexical analyzer scans left to right making the biggest token
>   possible.

Yes.

>2. Compound assignment tokens (ONLY) can be read as two consecutive
>   tokens (ie separated by whitespace ONLY) that are IMMEDIATELY
>   joined into one token.

Yes, but only in Classic C, not in New C (proposed ANSI standard C).

>3. Remaining ambiguity is resolved by simple (hah!) precedence and
>   associativity rules.

More or less.  C has no nonassociative operators, so every syntactically
correct expression has a defined grouping.  The result can still be
ambiguous in another sense, e.g.,

	p += *p++;

is easy to parse but hard to describe.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7163)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris