On 22-Sep-08 23:16, Darren New wrote:
> andrel wrote:
>> My point was always the other way around: does Haskell allow you to 
>> introduce concepts and control structures that from that point on will 
>> become conceptually 'part of the language' for you? 
> 
> No, I don't think it does. I don't think it's possible to write "case" 
> or "let" in Haskell. That's kind of the point.  I think you're taking 
> "reserved words" to mean the same as "meaningful concepts."  I'm talking 
> from the point of view of someone building a compiler or something, not 
> from someone conceptualizing about an application.
> 
>> To the extent that for you they behave like 'reserved words'. 
> 
> I don't care what it behaves like in my brain. I care what happens when 
> it compiles.

OK, so there is where we part. I don't want to think about hardware or 
compiler issues when I am solving a problem. (except when I end up 
writing a compiler of course). I want to express my thoughts in as clear 
a way as possible. If the language does not give me the freedom to 
express myself as I think is the most clear, I'll try to extend the 
language. Just as when I am doing math and I feel that I should need to 
introduce a new syntax. Standard and new syntax will form my new 
framework. Whatever someone else at any one time though were his 
fundamental concepts is immaterial to me.

> 
>>> OK, maybe I misphrased it. How does the compiler distinguish the 
>>> variable name from the syntactic form that "case" currently 
>>> introduces in Haskell?  If "you don't", then it means your compiler's 
>>> behavior is unspecified when you use the word "case" as a variable. 
>>> People generally don't like compiler behavior to be unspecified for 
>>> valid programs.
>>
>> Normal scoping rules may apply.
> 
> Then it wouldn't be a reserved word, would it? :-)
> 
> I don't know if Haskell actually disallows the use of variables named 
> the same as "reserved words", but if it doesn't, then that's a reserved 
> word.
> 

Let me reiterate, I don't even care if Haskell allows it or not. The 
discussion was if Haskell should visually make the distinction or not. 
To which my answer is no, because what is and what isn't a reserved word 
is too arbitrary. i.e. some are legitimate reserved (most of your 
examples are from that stock), some are reserved but a case could be 
made to relieve them of that status and some are not reserved, but might 
be. So fuzziness all over, hence: do not treat them visually different.

Post a reply to this message