Change to sync

[lvl99]

In reference to #50 :

I've made a quick stab at turning kuroshiro (and kuroshiro-analyzer-kuromoji) sync, and I found that the dependency kuromoji has lag when building the data files so requires callback/promise when initialising kuroshiro/kuroshiro-analyzer-kuromoji -- since @hexenq stated that other analyzers need to be async (although I haven't looked at those analyzers nor do I know if they require async parse), this is not a blocking issue to going sync IMO.

My exploration was mainly to see if it is easy enough to change the kuroshiro.convert to sync (it is at least with kuroshiro-analyzer-kuromoji). I would maybe advocate for creating additional functions with a Sync suffix to separate between async and sync return output. Other analyzers will need to support synchronous parse (i.e. parseSync) since that's used within kuroshiro.convert method: hexenq/kuroshiro-analyzer-kuromoji#6

[kyranet]

Random review from a random guy but... I hope it helps 😅

[kyranet]

I believe this should be the following:

Suggested change

	return Promise.resolve(this.convertSync(str, options));
	return Promise.resolve().then(() => this.convertSync(str, options));

This is based on what import(...) is transpiled to when targeting CommonJS, and this approach has a few benefits:

• The execution is delayed instead of done immediately (better async I/O).
• If this.convertSync(str, options) throws, this will cause a promise rejection, currently it throws a sync error, which makes .catch() not work.
• Much cleaner than a try/catch using Promise.resolve and Promise.reject.