This commit updates clap to v2.23.0
The update contained a bug fix in clap that results in broken code in
ripgrep. ripgrep was relying on the bug, but this commit fixes that
issue. The bug centered around not being able to override the
auto-generated help message by supplying a flag with a long of `help`.
Normally, supplying a flag with a long of `help` means whenever the user
passes `--help`, the consuming code (e.g. ripgrep) is responsible for
displaying the help message. However, due to the bug in clap this wasn't
necessary for ripgrep to do unless the user passed `-h`. With the bug
fixed, it meant the user passing `--help` and clap expected ripgrep to
display the help, yet ripgrep expected clap to display the help. This
has been fixed in this commit of ripgrep.
All well now!
v2.23.0 also brings the abilty to use `Arg::help` or `Arg::long_help`
allowing one to distinguish between `-h` and `--help`. This commit
leaves all doc strings in the `lazy_static!` hashmap however only for
aesthetic reasons.
This means all home rolled handling of `-h`/`--help` has been removed
from ripgrep, yet functionality *and* appearances are 100% the same.
Previously, `get_matches` would return even if --help or --version was
given, and we could check for them manually. That behavior seems to have
changed. Instead, we must use get_matches_safe to inspect the error to
determine what happened.
We can't use the same process for -V/--version since clap will
unconditionally print its own version info. Instead, we rename (internally)
the version flag so that clap doesn't interfere.
This permits setting the maximum line width with respect to the number
of bytes in a line. Omitted lines (whether part of a match, replacement
or context) are replaced with a message stating that the line was
elided.
Fixes#129
This changes the default behavior of ripgrep to *not* show line numbers
when it is printing to a tty and is only searching stdin.
Fixes#380
[breaking-change]
It's not clear what exactly is happening here, but the Read implementation
for text decoding appears a bit sensitive. Small pertubations in the code
appear to have a nearly 100% impact on the overall speed of ripgrep when
searching UTF-16 files.
I haven't had the time to examine the generated code in detail, but
`perf stat` seems to think that the instruction cache is performing a lot
worse when the code slows down. This might mean that excessive inlining
causes a different code structure that leads to less-than-optimal icache
usage, but it's at best a guess.
Explicitly disabling the inline for the cold path seems to help the
optimizer figure out the right thing.
This includes, but is not limited to, UTF-16, latin-1, GBK, EUC-JP and
Shift_JIS. (Courtesy of the `encoding_rs` crate.)
Specifically, this feature enables ripgrep to search files that are
encoded in an encoding other than UTF-8. The list of available encodings
is tied directly to what the `encoding_rs` crate supports, which is in
turn tied to the Encoding Standard. The full list of available encodings
can be found here: https://encoding.spec.whatwg.org/#concept-encoding-get
This pull request also introduces the notion that text encodings can be
automatically detected on a best effort basis. Currently, the only
support for this is checking for a UTF-16 bom. In all other cases, a
text encoding of `auto` (the default) implies a UTF-8 or ASCII
compatible source encoding. When a text encoding is otherwise specified,
it is unconditionally used for all files searched.
Since ripgrep's regex engine is fundamentally built on top of UTF-8,
this feature works by transcoding the files to be searched from their
source encoding to UTF-8. This transcoding only happens when:
1. `auto` is specified and a non-UTF-8 encoding is detected.
2. A specific encoding is given by end users (including UTF-8).
When transcoding occurs, errors are handled by automatically inserting
the Unicode replacement character. In this case, ripgrep's output is
guaranteed to be valid UTF-8 (excluding non-UTF-8 file paths, if they
are printed).
In all other cases, the source text is searched directly, which implies
an assumption that it is at least ASCII compatible, but where UTF-8 is
most useful. In this scenario, encoding errors are not detected. In this
case, ripgrep's output will match the input exactly, byte-for-byte.
This design may not be optimal in all cases, but it has some advantages:
1. In the happy path ("UTF-8 everywhere") remains happy. I have not been
able to witness any performance regressions.
2. In the non-UTF-8 path, implementation complexity is kept relatively
low. The cost here is transcoding itself. A potentially superior
implementation might build decoding of any encoding into the regex
engine itself. In particular, the fundamental problem with
transcoding everything first is that literal optimizations are nearly
negated.
Future work should entail improving the user experience. For example, we
might want to auto-detect more text encodings. A more elaborate UX
experience might permit end users to specify multiple text encodings,
although this seems hard to pull off in an ergonomic way.
Fixes#1
When writing paths like `!/foo` in gitignore files (or when using the
-g/--glob flag), the presence of `!` would prevent the gitignore builder
from noticing the leading slash, which causes absolute path matching to
fail.
Fixes#405
