path type path params can have default or be optional

[derekdai]

According to document

path: like string but includes / chars. Doesn't provides optional and default.

But in fact, HappyX can handle it without problem (checked with -d:spaDebug), with one exception $p:path=/, this generates incorrect regex (re2("^/photo-rename([\\S]+)=/$")), but {p:path=/} work as expect.

Currently, if there is a problem with the processing of path parameters, you can only use -d:spaDebug or -d:ssrDebug to view the generated code to confirm that it matches your expectations. Would it be appropriate to change this to a compile-time error?

[Ethosa]

yea, I updated path some time ago - #217
I'll update docs soon

[derekdai]

@Ethosa I think this is worth mentioning in the documentation. When specifying a default value for a path path parameter, the value may contain a / character, so you must use the {arg} syntax instead of $arg, according to this line. Or simply remove the "Usage alias" for path (and regex?) from "examples/website/src/docs/path_params.nim".

[Ethosa]

@derekdai

I add error throwing when developer tries to use alias for regex or path. Also I update docs