Re: Ada platforms and pricing, was: Re: a new language, designed for safety !

[Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP>]

On 2014-06-18, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
> On Wed, 18 Jun 2014 17:34:35 +0000 (UTC), Natasha Kerensikova wrote:
>
>> For some reason I'm much more frightened by parsing Ada text than by
>> code generation. I know the latter is probably not easier than the
>> former (I'm aware of LLVM vs nested functions), but who said fright is
>> rational?
>
> Oh, but parsing is really simple thing. You do recursive descent all the
> time. Except for expressions. For expressions you could take this:
>
> http://www.dmitry-kazakov.de/ada/components.htm#12.9
>

I agree parsing is a lot easier than code generation and I've written
a number of recursive descent parsers over the years.

However, off the top of my head, I don't understand why you can't parse
an Ada expression using recursive descent, especially if you have access
to the symbol table (if you need it). Do you have an example, because
the answer's probably obvious once you point it out. :-)

(I've never written a parser for Ada syntax, but I have written parsers
for various Wirth style languages in the past and I don't recall any
specific problems with expressions in those languages.)

Thanks,

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world