AST rendering for Handlebars

[HuJingKang]

Hi, I am using Handlebars for SSR in NodeJS.
By reading the source code, I learned that the rendering process is:
AST -> opcodes -> templateSpec -> eval(templateSpec) -> result.
Since the eval operation is time-consuming, I guess that if the rendering process is optimized to AST -> result, the performance may be greatly improved.
Could you please evaluate whether this optimization is feasible? Or is this an implementation that you have considered but was abandoned for some reason?

[jaylinski]

This may be possible, but it would probably be a very time-consuming and complex task.

[HuJingKang]

@jaylinski Recently I wrote a simple demo for this. Could you please help me to review the code and make some suggestions?
https://github.com/HuJingKang/fast-handlebars

[jaylinski]

I can take a look at it. What are the things you need input on?

[HuJingKang]

Thank you so much. Usage and input are no different from Handlebars. You can look at this:
https://github.com/HuJingKang/fast-handlebars/blob/main/examples/index.ts

[rickyes]

Hi, @jaylinski. We have refactored parser/render based on AST and benchmarked it to improve performance by about 3x, so you can help see if it can be incorporated into handlebars.js repository as an experimental feature.