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From: Niklas Holsti <niklas.holsti@tidorum.invalid>
Newsgroups: comp.lang.ada
Subject: Re: Verified compilers?
Date: Wed, 07 Mar 2012 19:49:04 +0200
Organization: Tidorum Ltd
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Date: 2012-03-07T19:49:04+02:00
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On 12-03-07 11:12 , Dmitry A. Kazakov wrote:

> I was always wondering why people bother to study grammars, LR, LL parsers
> and other useless stuff.

Grammars and the notion of parsing (derivations) rigorously define what 
a given string of characters means, in some formally defined language. 
That is fundamental to all programming and most computing.

As far as I can see, the only alternative would be to define the meaning 
of a language by defining a specific interpreter as the standard 
interpreter, and defining the meaning of a sentence as whatever this 
interpreter does, when interpreting this sentence.

> This is a great example of making a "science" out
> of nothing and for nothing.

The various types of grammars and the corresponding parsing procedures 
help us understand which parsing methods work for which kinds of 
grammars. This is useful even when one writes one's parsers by hand.

But I agree that the differences between the LR(k) languages, for 
various values of k, are mostly irrelevent in practice.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .