Thanks for explaining.

The thing was I thought if SLIF DSL could benefit from less diverse/more
strict — (pseudo-)rule/adverbs only — syntax and model, where

lexeme default statement becomes :lexeme default ::= pseudo rule


inaccessible statement becomes an adverb of
:default and/or :lexeme default pseudo-rules, e.g.


:default action => [name, values] inaccessible => ok

and


named event statement — event ( 'name' | name ) = ( completed | nulled |
predicted ) *symbol* — becomes an adverb of the rule whose LHS *symbol* is,
e.g.

                event subtext = completed <subtext>
                event 'A[]' = nulled <A>
                event '^a' = predicted A


become

                subtext ::= ... event completed => subtext
                <A> ::= ... event nulled => 'A[]'
                A ::= ... event predicted => '^a'


Heretic as it is, but I thought I'd better braindump it. :)

What do you think?



On Tue, Feb 25, 2014 at 8:11 PM, Jeffrey Kegler <
jeffreykeg...@jeffreykegler.com> wrote:

>  The "logic" goes like this.  Note the "=" instead of "::=".  This
> signals that the statement is not a rule, and is non-lexical -- it's
> location in the file does not matter.  Since it's not a rule, it does not
> take the form LHS ::= RHS2 ...
>
> The initial colon was for pseudo-symbols.  Since the lexeme default
> statement is not a rule, it does not have a LHS, so what appears before the
> equal sign ("=") is not considered symbol, pseudo- or otherwise.
>
> I am, frankly, less than 100% happy with this "logic" and my design
> choices, but there they are.
>
> In an ironic way, it does show Marpa's strength.  Because it allows and
> exploits ambiguity, I can "unpaint myself out of the corner", by
> introducing new statements and syntax.  Languages based on other parsers
> cannot evolve in that way.
>
> -- jeffrey
>
>  On 02/25/2014 08:25 AM, Ruslan Shvedov wrote:
>
>  Just caught myself thinking that
>
>  :default ::= action => [name, values]
> :lexeme default ::= latm => 1
>
>
>  looks like a bit more consistent (well, for some definitions of
> consistency at least) syntax than the current
>
>   :default ::= action => [name, values]
>  lexeme default = latm => 1
>
>
>  :default ::= ... and :lexeme ~ ... are pseudo-rules, but lexeme default
> = ... is a statement. This is by design, so I'd appreciate any information
> from those in the know.
>  --
> You received this message because you are subscribed to the Google Groups
> "marpa parser" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to marpa-parser+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>
>
>  --
> You received this message because you are subscribed to the Google Groups
> "marpa parser" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to marpa-parser+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
You received this message because you are subscribed to the Google Groups 
"marpa parser" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to marpa-parser+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to