Registers are lists of strings, so this make it possible to set
the whole list instead of forcing registers to a single element
when going through the set-register command.
Option lists and maps are specified using separate arguments, avoiding
the need for additional escaping of their separator and reusing the
existing command line spliting logic instead.
As discussed on #2087, this should make it much easier to work with
list options, and make the general option system feel cleaner.
Command line parsing now works as follow:
* Quoted strings ('...', "..." and %~...~ with '~' non nestable)
use 'doubling-up' for escaping their delimiter, if the delimiter
appears twice in a row, it is considered as part of the string and
represent one delimiter character. So 'abc''def' == "abc'def". No
other escaping takes place in those strings.
* Balanced strings (%{...}) do not support any kind of escaping, but
finds the matching closing delimiter by taking nesting into account.
So %{abc{def}} == "abc{def}".
* Non quoted words support escaping of `;` and whitespaces with `\`,
`%`, `'` and '"` can be escaped with `\` at the start of the word,
they do not need escaping (and will not be escaped) else where in
a word where they are treated literally. Any other use of '\' is a
literal '\'. So \%abc%\;\ def == "%abc%; def"
As discussed in #2046 this should make our command line syntax more
robust, provide a simple programmatic way to escape a string content
(s/<delim>/<delim><delim>/g), be well defined instead of ad-hoc
undocumented behaviour, and interact nicely with other common
escaping by avoiding escaping hell (:grep <regex> can in most case
be written with the regex unquoted).
Automatic reparsing of %sh{...}, while convenient in many cases,
can be surprising as well, and can lead to security problems:
'echo %sh{ printf "foo\necho bar" }' runs 'echo foo', then 'echo bar'.
we make this danger explicit, and we fix the 'nop %sh{...}' pattern.
To reparse %sh{...} strings, they can be passed to evaluate-commands,
which has been fixed to work in every cases where %sh{...} reparsing
was used..
I dedicate any and all copyright interest in this software to the
public domain. I make this dedication for the benefit of the public at
large and to the detriment of my heirs and successors. I intend this
dedication to be an overt act of relinquishment in perpetuity of all
present and future rights to this software under copyright law.
Note: `GNU/screen` has a different interpretation of what constitutes
a "vertical split", hence the inverted command descriptions, compared
to the tmux/iterm etc.
Closes#1626
