[Haskell-cafe] Custom unary operator extension?

Henning Thielemann lemming at henning-thielemann.de
Mon Sep 10 03:26:35 EDT 2007

On Sun, 9 Sep 2007, Peter Verswyvelen wrote:

> Henning Thielemann wrote:
>> The more syntactic constructs exist, the more complicated it becomes to 
>> read such programs. Today, if you read a symbolic operator which is not 
>> "-", not a single dot with a capital identifier to the left 
>> (qualification), not a double dot in a bracket (enumeration) and not 
>> enclosed in parentheses (prefix mode), then it is an infix operator. Note 
>> the already existing exceptions, and I feel these are not complete. With 
>> prefix operators it becomes more difficult.
> Okay, so the choice was to enhance readability. Yes, something can be said 
> for that, because in C++ and C#, operator overloading is a no-go in general, 
> in those language, it is prefered to use clear and long function names. But 
> as Haskell seemed more math-mind oriented, I was just wandering why unary 
> operator support was missing. Since students will surely ask me why I can't 
> create a symbolic operator for the "not" function, I now have a good answer 
> ready ;-)

I have read about APL that it uses a special character set in order to get 
a more mathematical looking notation. Maybe your students should check out 
this language?

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