[Feature Request] [stdlib] Add logic dunder methods for Tuple

[martinvuyk]

Review Mojo's priorities

• [X] I have read the roadmap and priorities and I believe this request falls within the priorities.

What is your request?

With an iterator: Implementing an iterator and comparing per item is an option.

With pointers: I still don't quite understand how to "safely" use the unsafe pointer. I think this implementation example would have a problem when say, comparing a Tuple[UInt64, UInt64] to a Tuple[UInt8, UInt8], but I'm not sure since I barely undestand the memcmp implementation.

Could do something like:

    fn _comp(self, other: Self) -> Optional[Int]:
        # doesn't have an __eq__ 
        # if self._mlir_type != other._mlir_type:
        if len(self) != len(other):
            return None
        return memcmp(
            UnsafePointer(self.storage).address,
            UnsafePointer(other.storage).address,
            len(self),
        )

    fn __eq__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] == 0 if result else False

    fn __ne__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] != 0 if result else False

    fn __gt__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] == 1 if result else False

    fn __ge__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] != -1 if result else False

    fn __lt__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] == -1 if result else False

    fn __le__(self, other: Self) -> Bool:
        var result = self._comp(other)
        return result.value()[] != 1 if result else False

What is your motivation for this change?

Some nice and intuitive syntax can come out of this

var result: Tuple[Int, UInt16, UInt8] = some_func()
if result == (0, 0, 0):
  return "some thing"
return "some other thing"

Any other details?

No response

[bgreni]

This memcmp approach won't work unfortunately, and I'm not sure the language has the features required yet to generically compare them properly.