Naming rotations

This issue seeks to settle the naming convention for factory functions that produce gate instances given rotation angles. I found the following factories:

Rx, Ry, Rz, GivensRotation, ISwapRotation, MS

These are clearly inconsistent. Proposals:

1. Rx, Ry, Rz, Rgivens, Riswap, Rms
2. rx, ry, rz, rgivens, riswap, rms
3. XRotation, YRotation, ZRotation, GivensRotation, ISwapRotation, MSRotation
4. x_rotation, y_rotation, z_rotation, givens_rotation, iswap_rotation, ms_rotation

I’m uneasy about conventions that lead to names like cirq.rms since this may be interpreted as “root mean square”.

To broaden the set of examples, here are some names we may reasonably anticipate in future:

Rzz, pauli_string_rotation

Context: comment

Thoughts?

[Strilanc]

Rx, Ry, Rz, Rgivens, Riswap, Rms

Rms reads like root mean square. Rgivens and Riswap are sorta logical given the first three, but very weird on their own. Violates python naming convention.

rx, ry, rz, rgivens, riswap, rms

rms reads like root mean square. rgivens and riswap are sorta logical given the first three, but very weird on their own. Semi-violates python naming convention in that there would normally be an underscore after the r.

XRotation, YRotation, ZRotation, GivensRotation, ISwapRotation, MSRotation

The names for X/Y/Z are too long IMO. The most common gates should have short names. MSRotation seems wrong; like saying HadamardRotation. I get what it means but it’s odd. Violates python naming convention.

x_rotation, y_rotation, z_rotation, givens_rotation, iswap_rotation, ms_rotation

Too long x/y/z. ms_rotation seems strange.

rx, ry, rz, givens, iswap, ms.

Lacks consistency across them, but honestly I like this one the best by far. Avoiding the rotation word for two qubit operations seems to be a good idea.

The only major problem, I think, is that it will be confusing to have iswap and ISWAP.

[mpharrigan]

ok