Basically, unless the -a/--text flag is given, it is generally always an
error to search for an explicit NUL byte because the binary detection
will prevent it from matching.
Fixes#1838
This does a little bit of refactoring so that we can pass both a
ConfiguredHIR and a Regex to the inner literal extraction routine.
One downside of this approach is that a regex object hangs on to a
ConfiguredHIR. But the extra memory usage is probably negligible. A
benefit though is that converting the HIR to its concrete syntax is now
lazy and only happens when logging is enabled.
This increases the limits a bit for when the regex engine will build and
use a fully compiled DFA. They can faster in some circumstances. For
example, '(?-u)^\w{30,}$' gets a nice speed boost from state
acceleration.
We are also able to remove `regex` proper as a dependency. Wow.
Previously, ripgrep core was responsible for escaping regex patterns and
implementing the --line-regexp flag. This commit moves that
responsibility down into the matchers such that ripgrep just needs to
hand the patterns it gets off to the matcher builder. The builder will
then take care of escaping and all that.
This was done to make pattern construction completely owned by the
matcher builders. With the arrival regex-automata, this means we can
move to the HIR very quickly and then never move back to the concrete
syntax. We can then build our regex directly from the HIR. This overall
can save quite a bit of time, especially when searching for large
dictionaries.
We still aren't quite as fast as GNU grep when searching something on
the scale of /usr/share/dict/words, but we are basically within spitting
distance. Prior to this, we were about an order of magnitude slower.
This architecture in particular lets us write a pretty simple fast path
that avoids AST parsing and HIR translation entirely: the case where one
is just searching for a literal. In that case, we can hand construct the
HIR directly.
Just some small polishing. We also get rid of thread_local in favor of
using regex-automata, mostly just in the name of reducing dependencies.
(We should eventually be able to drop thread_local completely.)
Now that Rust's regex crate finally supports a CRLF mode, we can remove
this giant hack in ripgrep to enable it. (And assuredly did not work in
all cases.)
The way this works in the regex engine is actually subtly different than
what ripgrep previously did. Namely, --crlf would previously treat
either \r\n or \n as a line terminator. But now it treats \r\n, \n and
\r as line terminators. In effect, it is implemented by treating \r and
\n as line terminators, but ^ and $ will never match at a position
between a \r and a \n.
So basically this means that $ will end up matching in more cases than
it might be intended too, but I don't expect this to be a big problem in
practice.
Note that passing --crlf to ripgrep and enabling CRLF mode in the regex
via the `R` inline flag (e.g., `(?R:$)`) are subtly different. The `R`
flag just controls the regex engine, but --crlf instructs all of ripgrep
to use \r\n as a line terminator. There are likely some inconsistencies
or corner cases that are wrong as a result of this cognitive dissonance,
but we choose to leave well enough alone for now.
Fixing this for real will probably require re-thinking how line
terminators are handled in ripgrep. For example, one "problem" with how
they're handled now is that ripgrep will re-insert its own line
terminators when printing output instead of copying the input. This is
maybe not so great and perhaps unexpected. (ripgrep probably can't get
away with not inserting any line terminators. Users probably expect
files that don't end with a line terminator whose last line matches to
have a line terminator inserted.)
This leaves the grep-regex crate in tatters. Pretty much the entire
thing needs to be re-worked. The upshot is that it should result in some
big simplifications. I hope.
The idea here is to drop down and actually use regex-automata 0.3
instead of the regex crate itself.
It turns out that if there are text anchors (that is, \A or \z, or ^/$
when multi-line is disabled), then the "fast" line searching path isn't
quite correct. Since searching without multi-line mode is exceptionally
rare, we just look for the presence of text anchors and specifically
disable the line terminator option in 'grep-regex'. This in turn
inhibits the "fast" line searching path.
Fixes#2260
The top-level listing was just getting a bit too long for my taste. So
put all of the code in one directory and shrink the large top-level mess
to a small top-level mess.
NOTE: This commit only contains renames. The subsequent commit will
actually make ripgrep build again. We do it this way with the naive hope
that this will make it easier for git history to track the renames.
Sigh.
