For compound commands we already have begin/end but
> it is long, which it is not convenient for the command line
> it is different than {} which shell users have been using for >50 years
The difference from {} can break muscle memory and add extra steps
when I'm trying to write simple commands that work in any shell.
Fix that by embracing the traditional style too.
---
Since { and } have always been special syntax in fish, we can also
allow
{ }
{ echo }
which I find intuitive even without having used a shell that supports
this (like zsh. The downside is that this doesn't work in some other
shells. The upside is in aesthetics and convenience (this is for
interactive use). Not completely sure about this.
---
This implementation adds a hack to the tokenizer: '{' is usually a
brace expansion. Make it compound command when in command position
(not something the tokenizer would normally know). We need to disable
this when parsing a freestanding argument lists (in "complete somecmd
-a "{true,false}"). It's not really clear what "read -t" should do.
For now, keep the existing behavior (don't parse compound statements).
Add another hack to increase backwards compatibility: parse something
like "{ foo }" as brace statement only if it has a space after
the opening brace. This style is less likely to be used for brace
expansion. Perhaps we can change this in future (I'll make a PR).
Use separate terminal token types for braces; we could make the
left brace an ordinary string token but since string tokens undergo
unescaping during expansion etc., every such place would need to know
whether it's dealing with a command or an argument. Certainly possible
but it seems simpler (especially for tab-completions) to strip braces
in the parser. We could change this.
---
In future we could allow the following alternative syntax (which is
invalid today).
if true {
}
if true; {
}
Closes#10895Closes#10898
Recent synopsis changes move from literal code blocks to
[RST line blocks]. This does not translate well to HTML: it's not
rendered in monospace, so aligment is lost. Additionally, we don't
get syntax highlighting in HTML, which adds differences to our code
samples which are highlighted.
We hard-wrap synopsis lines (like code blocks). To align continuation
lines in manpages we need [backslashes in weird places]. Combined with
the **, *, and `` markup, it's a bit hard to get the alignment right.
Fix these by moving synopsis sources back to code blocks and compute
HTML syntax highlighting and manpage markup with a custom Sphinx
extension.
The new Pygments lexer can tokenize a synopsis and assign the various
highlighting roles, which closely matches fish's syntax highlighing:
- command/keyword (dark blue)
- parameter (light blue)
- operator like and/or/not/&&/|| (cyan)
- grammar metacharacter (black)
For manpage output, we don't project the fish syntax highlighting
but follow the markup convention in GNU's man(1):
bold text type exactly as shown.
italic text replace with appropriate argument.
To make it easy to separate these two automatically, formalize that
(italic) placeholders must be uppercase; while all lowercase text is
interpreted literally (so rendered bold).
This makes manpages more consistent, see string-join(1) and and(1).
Implementation notes:
Since we want manpage formatting but Sphinx's Pygments highlighing
plugin does not support manpage output, add our custom "synopsis"
directive. This directive parses differently when manpage output is
specified. This means that the HTML and manpage build processes must
not share a cache, because the parsed doctrees are cached. Work around
this by using separate cache locations for build targets "sphinx-docs"
(which creates HTML) and "sphinx-manpages". A better solution would
be to only override Sphinx's ManualPageBuilder but that would take a
bit more code (ideally we could override ManualPageWriter but Sphinx
4.3.2 doesn't really support that).
---
Alternative solution: stick with line blocks but use roles like
:command: or :option: (or custom ones). While this would make it
possible to produce HTML that is consistent with code blocks (by adding
a bit of CSS), the source would look uglier and is harder to maintain.
(Let's say we want to add custom formatting to the [|] metacharacters
in HTML. This is much easier with the proposed patch.)
---
[RST line blocks]: https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#line-blocks
[backslashes in weird places]: https://github.com/fish-shell/fish-shell/pull/8626#discussion_r782837750
