[Haskell-cafe] map (-2) [1..5]

Brian Hulley brianh at metamilk.com
Thu Aug 17 19:20:54 EDT 2006

David House wrote:
> On 17/08/06, Brian Hulley <brianh at metamilk.com> wrote:
>> Literal highlighting in the editor would make it clear that x-2 ===
>> x (-2). I think a basic issue is that at the moment it is strange
>> that non-negative numbers can be specified as literals but negative
>> numbers can't - they can only get in through the "back door" of
>> evaluation - which just doesn't seem right.
> You also can't specify string literals: they're sugar for
> 'a':'b':'c':[]. You seem to be arguing that syntactic sugar, and by
> extension, a small core language, is bad.

All I'm saying is that given a type, either all the inhabitants should have 
a literal form or none of them should, because otherwise the availability of 
literals skews one's relationship to the inhabitants.

Ie the lack of negative literals tells me that I should think of negative 
integers as being "derived" from positive integers via negation, whereas the 

    data Integer = ... | -1 | 0 | 1 | ...

tells me that the negative and positive integers are on an equal footing.

Ie the language is sending out a "mixed message" about the integers, which 
is confusing.

Regards, Brian.
Logic empowers us and Love gives us purpose.
Yet still phantoms restless for eras long past,
congealed in the present in unthought forms,
strive mightily unseen to destroy us.


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