bitwise operators ~ | & |= &=

When I first designed the language, I realized the need to use & and | to represent union and intersection of types. Thus, at the value level, it made sense to interpret them as the same operations on Sets. Ceylon didn’t have bitwise operations at all, because:

• At the time I didn’t view it as a language for pushing bits and bytes around.
• We didn’t even have a Byte type, nor the Binary abstraction, and, furthermore, Integer did not specify its representation.
• I didn’t want to have operator overloading for & and |.
• I robbed ^ for exponentiation, and gave it a higher precedence than |.
• Parsing the bitshift operators >> and << is really much too painful, and I’m always getting confused between >> and >>>.

Since then, we introduced a Byte type, we added well-defined bitwise and bitshifting operations to Integer, and ultimately I’ve found myself using Sets much less than I expected, and Bytes much more. Oh, and we’ve already implicitly overloaded some operators to work on Java types.

Therefore, I propose to overload the operators |, &, |=, and &= to apply not only to Sets, but also to Binarys, and introduce a prefix ~ for bitwise complement.

Note:

• I’m not proposing to add ^ (xor), <<, >>, or >>>.
• Overloading these operators introduces an ambiguity, for types that inherit Set & Binary, but I think that problem is pretty easy to resolve.

[luolong]

While it is rare to use union and intersection on sets, it is by no means so rare that having operator support for these wouldn’t be useful.

[gavinking]

Done. I’m going to close, but feel free to post feedback here, if any. I can easily reopen the issue.