Unary operators implemented.

[XXjcontiniXX]

Make sure to read the contributing guidelines before submitting a PR

[reeselevine]

instead of calling this xielu_params, call it extra_params, so it's more general for other future unary operators

[reeselevine]

ok, after thinking about this more, my opinion is that we don't want to duplicate these relatively complicated statements across the different variants. I realize that this is what I do in bin_op.tmpl.wgsl, but in that case the operation is a single character.

So, my opinion here is that there are two options:

• Add a DECL for each operator with a custom update function, and reuse that for all the variants of a given operator.
• Modify embed_wgsl.py to add the ability to reuse REPLS across different variants. For example, the REPLS block could be specified like this:

"REPLS": {
  "FUNC": "XIELU_FUNC"
  }

And somewhere else, have a new block that's something like this:

#define REPLS
{
  "XIELU_FUNC": ...
  "EXP_FUNC": ...
  ....
}

Which you would then expand before calling replace_placeholders in embed_wgsl.py

Let me know what you think of both of these options and if you think either one would be better.