I guess this complaint should really be pointed at TypeScript, or even to C#, but also to Jsig...<p>It's really sad that different languages keep pushing `=>` for "function" type, instead of `->`, which has been the standard mathematical notations for a long time...
I'm wary of things like this. They tend to require more cognitive effort than either of the alternatives: strict typing or a purist version of duck typing. That javascript makes either of those difficult or impossible (the former for obvious reasons and the latter because of flexible implicit conversion rules and an inflexible message receiver mechanism) is a failing of javascript that can't really be bandaided over with something optional.<p>I just think that this is, with even the best intentions, extremely prone to bitrot.
I'm actually not really sure that it's more readable than the JSDoc way : /<p>I think that it's fine for very small projects, but if you want to share your docs, it's better to use an already conventioned syntax, which already solves edge cases (such as deeply nested callbacks).<p>For reference : <a href="http://usejsdoc.org/tags-callback.html" rel="nofollow">http://usejsdoc.org/tags-callback.html</a>
If adding signatures to a codebase, why not use the closure syntax? Because then you also get a compiler which gives you nice warnings as well as better minification.