On Aug 4, 2006, at 1:12 PM, Martin Percossi wrote:
Hi, I'm wondering what the rationale was for not allowing capitalized variable names (and uncapitalized type names and constructors). I can only think of two arguments, and IMHO both of them are bad:
1. Enforces a naming convention. Fine - but my view is that this doesn't belong in the language definition (it belongs in the user's coding standards). I get annoyed, for example, that when I write code that manipulates matrices and vectors, I can't refer to the matrices with capital letters as is common in the literature.
This is occasionally irritating.
And to anyone who says that it's good to enforce naming consistency, I have this to say: Any language that requires me to learn about category theory in order to write imperative code should treat me like an adult when it comes to the naming of variables as well. ;-)
2. It makes it easier to write the compiler. I don't think I need to explain why this is bad...
Eh? I'm not convinced this is a bad reason. It obviously needs to be balanced against other competing factors, but ease of implementation should always a consideration when designing a language. 3. It removes a whole class of possible ambiguities from the language. You the programmer (and the compiler, as an added bonus) can always identify the syntactic class of an identifier from _purely local_ context. Suppose I remove the case restriction. Is the following a pattern match or a function definition? Is M a variable or a data constructor? let f x M = z M in .... You can't tell! Worse, it could change depending on what identifiers are in scope. It could happen that you import a module and it silently causes your function definition to change to a pattern match. The situation is similar with type classes and type variables. You could magically end up with an instance declaration that is less polymorphic than you expect (if you have extensions turned on).
I imagine that someone is just itching to "sort me out". Do your worst! ;-)
Thx Martin
Rob Dockins Speak softly and drive a Sherman tank. Laugh hard; it's a long way to the bank. -- TMBG