- Have the `jsx` helper do the `defaultProps` work instead of calling `defaultProps` inline.
- Put `key` after `props` and make it optional.
- Inline `children` as rest args instead of in the object.
- Rename `createRawReactElement` to `jsx`. I wish I was kidding.
Most of these are silly microoptimizations. In my test file (based off an internal RN app), this reduces the parsing overhead of inlining from around 1% to 0.1% in JSC and from 0.6% to 0.0% in V8 (compared to element inlining before this commit).
Once parsed, the initial render with inlining is the same speed as not inlining in JSC and ~1% slower in V8. A second initial render in the same context (reusing the function objects, JIT, etc) is 2.0% faster in JSC and 5.5% faster in V8.
Either due to lower parsing costs or better type inference, this seems
to perform better than direct object inlining. (All along, the main win
was skipping a loop through props, not avoiding a function call.)
I'm extremely stupid and didn't commit as I go. To anyone reading this
I'm extremely sorry. A lot of these changes are very broad and I plan on
releasing Babel 6.0.0 today live on stage at Ember Camp London so I'm
afraid I couldn't wait. If you're ever in London I'll buy you a beer
(or assorted beverage!) to make up for it, also I'll kiss your feet and
give you a back massage, maybe.