Re: Lack of formal syntax undermines Ada

[Florian Weimer <fw@deneb.enyo.de>]

> Ada does not have a formal syntax. The LRM provides "syntax rules"
> section by section, then collectively in Annex P. The resulting
> woolly grammar is well-known to be ambiguous (e.g. is X:=Y(Z) an
> assignment from a function call, array indexing or something
> else?). It mixes lexical and syntactical information. It cannot
> be used as the input to a parser generator. The interpretation
> necessary via other sections of the LRM risks making the language
> as a whole indefinite.

It shares this property with other many other languages.  For example,
the Definition of Standard ML contains mostly correct formal semantics
of the language, but the grammar suffers from a few ambiguities which
actually arise in practice.  I'm sure there are other examples.

After all, syntax is easy.  Getting the semantics right is the difficult
part.

I agree that some additional formalism might not hurt, but it's probably
better if that effort goes into an improved description of the semantics
(assuming that there are limited resources to create the language
standard).  At least that's how I try to explain this phenomenon to
myself.