Re: Bug in TeX input mode?

[Deniz Dogan]

2009/6/17 Chong Yidong <address@hidden>:
> Deniz Dogan <address@hidden> writes:
>
>> \circ in the TeX input mode inserts the following character:
>>
>>         character: ○ (9675, #o22713, #x25cb)
>>   name: WHITE CIRCLE
>>   general-category: So (Symbol, Other)
>>
>> However, we feel like what should have been inserted is this:
>>
>>         character: ∘ (8728, #o21030, #x2218)
>>   name: RING OPERATOR
>>   general-category: Sm (Symbol, Math)
>
> Maybe.  But if you look at the TeX output of \circ, the size of the
> circle looks a lot more like ○ than ∘ (at least, when using DejaVu Sans
> Mono, I haven't checked with other fonts).  And it seems more reasonable
> for "\circ" to mean WHITE CIRCLE than RING OPERATOR.
>

That's weird, because I'm using the same font and I think it looks way
much more like ∘! :) The Haskellers I talked to said that \circ is the
standard way of writing the "function composition operator" in TeX and
IIRC, the function composition operator is sometimes called "ring
operator", due to its shape. Copy-pasting the composition operator
from Wikipedia reveals that they use the Unicode RING OPERATOR as
well, but of course, this needn't mean that TeX does...

-- 
Deniz Dogan