Handlebars parsing slow-ish on Android Webkit

[pamelafox]

I've been checking out the parse times for Handlebars in my Android PhoneGap app, and I'm seeing the longest times for Handlebars - in a range from 50 to 90 milliseconds. My app JS files are from 10-40ms, and other JS libs are 0-35. A screenshot of times for the last 2 runs is here: http://dl.dropbox.com/u/10998095/Screenshots/5m72gn3r8mqi.png

My measurement technique is simple, I log the time before and after the Handlebars.js script is parsed. The handlebars.js is part of a longer JS file, so the JS file has already been loaded by the time it starts parsing it - i.e. the 50-90ms should not include load time.

I haven't spent much time in the Handlebars code, so I hoped I could get some insight here as to where the extra parse time might be coming from - basically, what sort of things does Handlebars do besides function definitions when the code is first parsed?

I'm also surprised to see it vary so much, from 50-90, as most of the other JS libs are fairly consistent across runs, and it makes me wonder where the variance is from.

Thanks!

[wagenet]

You can, and probably should, precompile your Handlebars templates.

[pamelafox]

Ah! Good point. I do pre-compile my templates, but I neglected to use the runtime build instead of the normal one. I'll make that substitution today and report on the results. Thanks for pointing that out.

[pamelafox]

Confirmed that the runtime is much faster (5-10ms).

Small n00b request: It'd be nice if the handlebars-runtime in https://github.com/wycats/handlebars.js/downloads ended in ".js", as it took me a few minutes to figure out that it was a text file, not an archive (and my Mac had no idea).

[wagenet]

@pamelafox Looks like an accident, since beta5 has .js.