This takes the previous alternation optimisation and applies it to all
the alternation blocks instead of just the few instructions at the
start.
By generating a trie of instructions, all logically equivalent
instructions will be consolidated into a single node, allowing the
engine to avoid checking the same thing multiple times.
For instance, given the pattern /abc|ac|ab/, this optimisation would
generate the following tree:
- a
| - b
| | - c
| | | - <accept>
| | - <accept>
| - c
| | - <accept>
which will attempt to match 'a' or 'b' only once, and would also limit
the number of backtrackings performed in case alternatives fails to
match.
This optimisation is currently gated behind a simple cost model that
estimates the number of instructions generated, which is pessimistic for
small patterns, though the change in performance in such patterns is not
particularly large.
The consume(size_t) overload consumes "at most" as many bytes as
requested, but consume() consumes exactly one byte.
This commit makes sure to avoid consuming past EOF.
Fixes#18324.
Fixes#18325.
If a block jumps before performing a compare, we'd need to recursively
find the first of the jumped-to block. While this is doable, it's not
really worth spending the time as most such cases won't actually qualify
for atomic loop rewrite anyway.
Fixes an invalid rewrite when `.+` is followed by an alternation, e.g.
/.+(a|b|c)/.
Previously we were only checking for overlap when the range wasn't in
inverse mode, which made us miss things like /[^x]x/; this patch makes
it so we don't miss that.
Having an alias function that only wraps another one is silly, and
keeping the more obvious name should flush out more uses of deprecated
strings.
No behavior change.
Previously, if a pattern matched the empty string (e.g. ".*"), it would
match the string twice instead of once. Among other issues, this caused
a Regex replacement to duplicate its expected output, since it would
replace "both" empty matches.
In 7c5e30daaa, the focus was "only" on
Userland/Libraries/, whereas this commit cleans up the remaining
headers in the repo, and any new badly-formatted include.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This test file had #ifdef macros at the top that caused none of the
content to be compiled unless a developer manually wanted to run the
specific benchmarks within. As such, it has become stale. Remove it for
now, if someone wants to restore it in an always-runnable state, we can
restore the specific tests it's trying to benchmark.
Currently, LibUnicodeData contains the generated UCD and CLDR data. Move
the UCD data to the main LibUnicode library, and rename LibUnicodeData
to LibLocaleData. This is another prepatory change to migrate to
LibLocale.
Previously, for a regex such as /[a-sy-z]/i, we would incorrectly think
the character "u" fell into the range "a-s" because neither of the
conditions "u > s && U > s" or "u < a && U < a" would be true, resulting
in the lookup falling back to assuming the character is in the range.
Instead, first explicitly check if the character falls into the range,
rather than checking if it falls outside the range. If the explicit
checks fail, then we know the character is outside the range.
This prevents us from needing a sv suffix, and potentially reduces the
need to run generic code for a single character (as contains,
starts_with, ends_with etc. for a char will be just a length and
equality check).
No functional changes.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
[^XYZ] is not(X | Y | Z), we used to translate this to
not(X) | not(Y) | not(Z), this commit makes LibRegex interpret this
pattern as not(X) & not(Y) & not(Z).
The lowercase version of a range is not required to be a valid range,
instead of casefolding the range and making it invalid, check twice with
both cases of the input character (which are the same as the input if
not insensitive).
This time includes an actual test :^)
We had a really naive and simplistic implementation, which lead to
various issues where the optimiser incorrectly rewrote the regex to use
atomic groups; this commit fixes that.
While quantifying assertions is very much meaningless, the specification
allows them with annex B's extended grammar for browsers, so read and
apply the quantifiers.
Fixes#12373.
ECMA-262 defines \s as:
Return the CharSet containing all characters corresponding to a code
point on the right-hand side of the WhiteSpace or LineTerminator
productions.
The LineTerminator production is simply: U+000A, U+000D, U+2028, or
U+2029. Unfortunately there isn't a Unicode property that covers just
those code points.
The WhiteSpace production is: U+0009, U+000B, U+000C, U+FEFF, or any
code point with the Space_Separator general category.
If the Unicode generators are disabled, this will fall back to ASCII
space code points.
LibRegex already implements this loop in a more performant way, so all
LibJS has to do here is to return things in the right shape, and not
loop over the input string.
Previously this was a quadratic operation on string length, which lead
to crazy execution times on failing regexps - now it's nice and fast :^)
Note that a Regex test has to be updated to remove the stateful flag as
it repeats matching on multiple strings.
As ECMA262 regex allows `[^]` and literal newlines to match newlines in
the input string, we shouldn't split the input string into lines, rather
simply make boundaries and catchall patterns capable of checking for
these conditions specifically.
Instead of leaking all capture groups and selectively clearing some,
simply avoid leaking things and only "define" the ones that need to
exist.
This *actually* implements the capture groups ECMA262 quirk.
Also adds the test removed in the previous commit (to avoid messing up
test runs across bisects).
This partially reverts commit c11be92e23.
That commit fixes one thing and breaks many more, a next commit will
implement this quirk in a more sane way.
Previously we were jumping to the new end of the previous block (created
by the newly inserted ForkStay), correct the offset to jump to the
correct block as shown in the comments.
Fixes#12033.
