Spacen Jasset <[email protected]> wrote:
On 13/03/2011 00:06, Bekenn wrote:
On 3/12/2011 2:20 PM, Simon wrote:
I've done lots of 3d over the years and used quite a lot of different
libraries and I've come to prefer code that makes a distinction between
points and vectors.
Agreed. This has some nice benefits with operator overloading, as well:
vec v = ...;
pt p = ...;
auto p2 = p + v; // p2 is pt
auto p3 = p + p2; // error
auto v2 = v + v; // v2 is vec
...and with properties:
p.x = 5; // p is pt, sets p._vals[0]
v.dx = 3; // v is vec, sets v._vals[0]
Would you then go on to define things like a cross product as an
operator overload?
Can't see a fitting operator in D. Multiplication (*) is ambiguous at best
and no other operator seems fitting.
I'd like to have more of unicode's mathematical operators and symbols[1]
as operators in D, but currently that's beyond the horizon.
Use cases:
Vector a, b;
auto angle = a ∠ b;
assert( a == (b ∓ .1) );
assert( ( a ∟ b ) == ( angle == degrees( 90 ) ) );
assert( a ∥ b );
auto v = a ⋅ b;
Set c = ∅, d = ∅;
auto union = c ∪ d;
auto intersection = c ∩ d;
assert( "foo" ∈ c );
assert( "foo" ∉ d );
assert( d ∌ "foo" );
assert( c ∋ "foo" );
assert( d ⊂ c );
assert( d ⊅ c );
assert( ∏[1,2,3] == ∑[1,2,3] );
Of course, this requires a method for typing these symbols, something
which TeX has already solved for us.
[1]:
http://en.wikipedia.org/wiki/Mathematical_operators_and_symbols_in_Unicode
--
Simen
