Actually, the SLIF allows angle brackets, but they are optional for
non-terminals.
His analysis of the types of ambiguity is interesting. What I call
factoring he calls "associativity", and what I call "symbolic choice"
(or symch)
<http://search.cpan.org/%7Ejkegl/Marpa-R2-2.087_001/pod/Glade.pod>, he
calls alternate routes (or multiple paths). My problem would be that
different factorings *also* allow alternate routes, so that I find the
linked-to page's terminology to be kind of confusing. Nonetheless he
does have the taxonomy, one which I had to discover, for doing the
abstract syntax forests. I wonder if Prof Heckendorn rediscovered it,
or if it's stated clearly in the literature somewhere and I'd just
missed it.
It was certainly implicit in the literature. "Factoring" was
distinguished as a special type of ambiguity, so by implication there
are factorings and non-factorings.
-- jeffrey
On 07/25/2014 03:31 AM, rns wrote:
Messed up the link, sorry, this one works:
http://marvin.cs.uidaho.edu/Teaching/CS445/grammar.html
On Friday, July 25, 2014 1:29:59 PM UTC+3, rns wrote:
http://marvin.cs.uidaho.edu/Teaching/CS445/grammar.htm
<http://marvin.cs.uidaho.edu/Teaching/CS445/grammar.htm>— that is.
Very gentle and informal, but dense and informative, covering
(E)BNF, precedence, associativity, ambiguity, tips for grammar
writing and useful examples.
What I find both useful and amusing:
(1) the grammar syntax is nearly SLIF, sans the angle brackets; so
(1a) examples can be fed to Marpa::R2::Scanless::G almost as they
are; but
(1b) 'grammar' is not described as a thing that can be used easily
to 'parse', e.g.:
A grammar is used to specify the syntax of a language. It
answers the question: What sentences are in the language and
what are not?
*Parse *is to show how a sentence could be built from a grammar
A sure sign of pre-Marpa days when grammar were written mostly as
a specification for humans, as was frequently discussed in this group.
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