The ability to negate any boolean flags itself is great, but I think we are not
ready to expose the help side of it yet.
First, while there exist a handful of such flags whose default value can be
changed (eg: git diff, patchwork confirmation), there is only a few of them. The
users who benefit the most from this change are alias users and large
installation that can deploy extension to change behavior (eg: facebook
tweakdefault). So the majority of user who will be affected by a large change
to command help that is not yet relevant to them. (I expect this to become
relevant when ui.progressive start to exists).
Below is an example of the impact of the new help on 'hg help diff':
-r --rev REV [+] revision
-c --change REV change made by revision
-a --[no-]text treat all files as text
-g --[no-]git use git extended diff format
--[no-]nodates omit dates from diff headers
--[no-]noprefix omit a/ and b/ prefixes from filenames
-p --[no-]show-function show which function each change is in
--[no-]reverse produce a diff that undoes the changes
-w --[no-]ignore-all-space ignore white space when comparing lines
-b --[no-]ignore-space-change ignore changes in the amount of white space
-B --[no-]ignore-blank-lines ignore changes whose lines are all blank
-U --unified NUM number of lines of context to show
--[no-]stat output diffstat-style summary of changes
--root DIR produce diffs relative to subdirectory
-I --include PATTERN [+] include names matching the given patterns
-X --exclude PATTERN [+] exclude names matching the given patterns
-S --[no-]subrepos recurse into subrepositories
Another issue with the current state of help, the default value for the
flag is not conveyed to the user. For example in the 'backout' help, there is
no real distinction between "--[no-]backup" (default to True) and "--[no-]keep"
(default) to False:
--[no-]backup no backups
--[no-]keep do not modify working directory during strip
In addition, I've discussed with Augie Fackler and the last batch of the work on
this have burned him out quite some. Therefore he is not intending to perform
any more work on this topic. Quoting him, he would rather see the help part
backed out than spending more time on it.
I do not think we are ready to expose this to users in 4.0 (freeze in a week),
especially because we cannot expect quick improvement on these aspect as this
topic no longer have an owner. We should be able to reintroduce that change in
the future when someone get back on it and the main issues are solves:
* Introduction of ui.progressive makes it relevant for a majority of user,
* Current default value are efficiently conveyed to the user.
(In addition, the excerpt from diff help show that we still have some issue with
some negative option like '--nodates' so further improvement are probably
welcome there.)
That is, help gets tweaked thus:
global options ([+] can be repeated):
-v --[no-]verbose enable additional output
Other proposals have included:
global options ([+] can be repeated, options marked [?] are boolean flags):
-v --verbose[?] enable additional output
and
global options ([+] can be repeated, options marked [^] are boolean flags):
-v --verbose[^] enable additional output
which avoid the unfortunate visual noise in this patch. In this
version's favor, it's consistent with what I'm used to seeing in man
pages and similar documentation venues.
Mercurial would sometimes exit with:
abort: No such file or directory
where str of the actual OSError exception was the more helpful:
[Errno 2] No such file or directory: ''
The exception will now always show the filename and quote it:
abort: No such file or directory: ''
Example
$ hg clone --jump foo bar
hg clone: option --jump not recognized
hg clone [OPTION]... SOURCE [DEST]
make a copy of an existing repository
options:
-U --noupdate the clone will include an empty working copy (only a
repository)
-u --updaterev REV revision, tag or branch to check out
-r --rev REV [+] include the specified changeset
-b --branch BRANCH [+] clone only the specified branch
--pull use pull protocol to copy metadata
--uncompressed use uncompressed transfer (fast over LAN)
-e --ssh CMD specify ssh command to use
--remotecmd CMD specify hg command to run on the remote side
--insecure do not verify server certificate (ignoring
web.cacerts config)
[+] marked option can be specified multiple times
use "hg help clone" to show the full help text
Motivation for this change
If the user already has specified the command, he probably already knows
the command to some extent. Apparently, he has a problem with the options,
so we show him just the synopsis with the short help and the details about
the options, with a hint on the last line how to get the full help text.
Why is Mercurial better with this change?
Experts who just forgot about the details of an option don't get that
much text thrown at them, while the newbies still get a hint on the last
line how to get the full help text.
