Syntax vs Operators

Syntax vs Operators

[Jacques Carette]

I have been going through the documentation, trying to figure out which 
constructs in Ocaml are syntactic (like :: seems to be) and cannot be 
oer-ridden, and others like + which are values in Pervasives.  Is there 
a simple way to find out which language constructs are purely syntactic?

The goal is to understand which constructs can be re-defined (locally) 
in a module.  The eventual application is a more genial syntax for a DSL 
implemented via MetaOCaml (and more functors than anyone in their right 
mind would really want to use...).

Jacques

Re: [Caml-list] Syntax vs Operators

[Damien Doligez]

On Aug 22, 2005, at 17:55, Jacques Carette wrote:

> I have been going through the documentation, trying to figure out  
> which constructs in Ocaml are syntactic (like :: seems to be) and  
> cannot be oer-ridden, and others like + which are values in  
> Pervasives.  Is there a simple way to find out which language  
> constructs are purely syntactic?

You should look a the lexer documentation:
< http://caml.inria.fr/pub/docs/manual-ocaml/manual009.html >,
in the section titled "Prefix and Infix Symbols", you will get the  
syntax of
all the user-definable symbols.  Some of them are predefined, but you  
are
guaranteed to be able to override them.  You should avoid overriding  
the ones
that are listed as keywords (in the next section), even if some of them
are actually redefinable in the current implementations.

-- Damien

Re: [Caml-list] Syntax vs Operators

[Jacques Carette]

Damien Doligez wrote:

> On Aug 22, 2005, at 17:55, Jacques Carette wrote:
>
>> I have been going through the documentation, trying to figure out  
>> which constructs in Ocaml are syntactic (like :: seems to be) and  
>> cannot be oer-ridden, and others like + which are values in  
>> Pervasives.  Is there a simple way to find out which language  
>> constructs are purely syntactic?
>
>
> You should look a the lexer documentation:
> < http://caml.inria.fr/pub/docs/manual-ocaml/manual009.html >,
> in the section titled "Prefix and Infix Symbols", you will get the  
> syntax of
> all the user-definable symbols.  Some of them are predefined, but you  
> are
> guaranteed to be able to override them.  You should avoid overriding  
> the ones
> that are listed as keywords (in the next section), even if some of them
> are actually redefinable in the current implementations.
>
Actually, the whole point of this question is that I want to 
redefine/override them - and I wanted to find out which I could not.  I 
know I can override + if I want, I want to know about the ones like :: 
which have a pre-defined meaning but can not be overridden.  By 
carefully reading sections 9 and 15 of the manual, I have managed to 
extract this information - I was just hoping that there was something 
simpler that I had somehow overlooked.

The point is to see how much of a DSL I can create in Ocaml, using Ocaml 
syntax, by using lots of Functors.  Very much in the spirit of the 
Lua-ML interpreter in fact, except that I want to use Caml syntax rather 
than having to parse a new language.  Or I may decide to adapt the 
camlp4 macros for the ``revised syntax'' for my purposes.

Jacques

Re: [Caml-list] Syntax vs Operators

[Damien Doligez]

On Aug 23, 2005, at 20:05, Jacques Carette wrote:

> Actually, the whole point of this question is that I want to  
> redefine/override them
> - and I wanted to find out which I could not.  I know I can  
> override + if I want,
> I want to know about the ones like :: which have a pre-defined  
> meaning but can not
> be overridden.

Maybe I'm overlooking something, but I think the ones in the  
"keywords" list
are the ones that you cannot or should not override.

> The point is to see how much of a DSL I can create in Ocaml, using  
> Ocaml syntax,
> by using lots of Functors.  Very much in the spirit of the Lua-ML  
> interpreter in
> fact, except that I want to use Caml syntax rather than having to  
> parse a new
> language.

If it's a DSL that includes OCaml as a sublanguage, I think at some  
point you
will have users who want to use the OCaml features that you are hiding.

-- Damien