type annotation

[Freed-Wu]

What is the problem this feature will solve?

Many LSP support type annotations. Such as:

• lua-language-server for lua
• tsc for js
• pyright for python

Is it possible to support type annotations for bash? e.g.,

# This should be a brief description of the package and its functionality. Try
# to keep the description to one line of text and to not use the package's name.
#@type string
pkgdesc='default value'

# Defines on which architectures the given package is available (e.g.,
# arch=(i686 x86_64)). Packages that contain no architecture specific files
# should use arch=(any). Valid characters for members of this array are
# alphanumerics and "_".
#@type string[]
arch=()

If we write arch=x86_64 we will get error.
except we change string[] to string[] | string or string[] | 'x86_64'

And we will get document hover from the comment before variable.

And we can introduce more types. like 'true' | 'false' for bool, /\d+/ for number.
@param 1: 'true' | 'false' for function input $1. Even we can define new types. like:
@typedef boolean: 'true' | 'false'

What is the feature you are proposing to solve the problem?

type annotation

What alternatives have you considered?

termux-language-server use json schema to annotate type of variables. However, it is specific, not flexible.
For PKGBUILD, there is a PKGBUILD.json.
If we realize type annotation, we can use PKGBUILD.d.sh, %.ebuild.sh, build.sh.d.sh for PKGBUILD, ebuild, build.sh.
We even can introduce some magic comments. e.g., we add #@source PKGBUILD.d.sh to test.sh, it will use types of PKGBUILD.d.sh.
or #@source https://a_URL_like_DefinitelyTyped/PKGBUILD.d.sh.

*.d.sh is like *.d.ts. It is also helpful for other projects like shellcheck.

And some bash script provide some function as a wrapper of source. such as ebuild's inherit.

If we inherit toolchain-funcs, it will source $EPREFIX/var/db/repos/gentoo/eclass/toolchain-funcs.eclass and user can use the functions defined toolchain-funcs.eclass. we can use the code
in %.ebuild.d.sh:

inherit() {
  source $EPREFIX/var/db/repos/gentoo/eclass/$1.eclass
}

Like after import XXX then use functions defined in XXX.py? Attractive and a little hard to realize?

Just my 2c. Welcome to discuss!