Re: GDB/MI Output Syntax

[Andrew Cagney <cagney@gnu.org>]

> Hi,
> 
> Along with the newline changes, there are 2 other changes that I propose
> to the grammar. They are,
> 
> async-record   ==> exec-async-output | status-async-output | notify-async-output
> exec-async-output    ==> [ token ] "*" async-output
> status-async-output  ==> [ token ] "+" async-output
> notify-async-output  ==> [ token ] "=" async-output]

FYI, these were done this way so that the complete structure and intent 
was clear (rather than worry about language issues).  As you note a 
rewrite gives an ll(1) grammar; it also looses that clarity.

> to 
> 
>    async-record ==> [token] async-record-kind async-output
>    async-record-kind ==> "*" | "+" | "="
> 
> however, if you really would like to keep the *-async-output rules, we
> could do
> 
>    async-record ==> [token] async-record-kind async-output
>    async-record-kind ==> exec-async-output | status-async-output | notify-async-output
>    exec-async-output    ==> "*"
>    status-async-output  ==> "+"
>    notify-async-output  ==> "=" 

I can see something like (better names):

	async-record ==> [token] async-output
	async-output ==> exec-async-output | ...
	exec-async-output ==> "*" async-result

	async-result ==> async-class ( "," @var{result} )* @var{nl}

> The second change is identical but refers to the rules of
>    stream-record ==> console-stream-output | target-stream-output | log-stream-output
>    console-stream-output ==> "~" c-string
>    target-stream-output ==> "@" c-string
>    log-stream-output ==> "&" c-string
> 
> to
>    stream-record => stream-record-kind c-string
>    stream-record-kind => "~" | "@" | "&"
> 
> The reason it would be helpful to modify the grammar in this way is that
> it leads to a more elegant form when trying to build an intermediate
> representation. At the parse level of 'stream-record' or 'async-record'
> you have all of the information necessary in order to populate a
> structure with data. Otherwise, the information is a few levels down
> stream.

I don't follow.

Andrew