Presently the completion engine ignores builtins that are part of the
fish syntax. This can be a problem when completing a string that was
based on the output of `commandline -p`. This changes completions to
treat these builtins like any other command.
This also disables generic (filename) completion inside comments and
after strings that do not tokenize.
Additionally, comments are stripped off the output of `commandline -p`.
Fixes#5415Fixes#2705
Consider a group of short options, like -xzPARAM, where x and z are options and z takes an argument.
This commit enables completion of the argument to the last option (z), both within the same
token (-xzP) or in the next one (-xz P).
complete -C'-xz' will complete only parameters to z.
complete -C'-xz ' will complete only parameters to z if z requires a parameter
otherwise, it will also complete non-option parameters
To do so this implements a heuristic to differentiate such strings from single long options. To
detect whether our token contains some short options, we only require the first character after the
dash (here x) to be an option. Previously, all characters had to be short options. The last option
in our example is z. Everything after the last option is assumed to be a parameter to the last
option.
Assume there is also a single long option -x-foo, then complete -C'-x' will suggest both -x-foo and
-xy. However, when the single option x requires an argument, this will not suggest -x-foo.
However, I assume this will almost never happen in practise since completions very rarely mix
short and single long options.
Fixes#332
