The implementation of digit-separating single-quotes introduced a
note-worthy regression: the change of a character literal with a
digit would splice the digit and the closing single-quote. For
example, the change from 'a' to '2' is now tokenized as
'[-a'-]{+2'+} instead of '[-a-]{+2+}'.
The options to fix the regression are:
- Tighten the regular expression such that the single-quote can only
occur between digits (that would match the official syntax).
- Remove support for digit separators.
I chose to remove support, because
- I have not seen a lot of code make use of digit separators.
- If code does use digit separators, then the numbers are typically
long. If a change in one of the segments occurs, it is actually
better visible if only that segment is highlighted as the word
that changed instead of the whole long number.
This choice does introduce another minor regression, though, which
is highlighted in the test case: when a change occurs in the second
or later segment of a hexadecimal number where the segment begins
with a digit, but also has letters, the segment is mistaken as
consisting of a number and an identifier. I can live with that.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since C++20, the language has a generalized comparison operator <=>.
Teach the cpp driver not to separate it into <= and > tokens.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since C++17, the single-quote can be used as digit separator:
3.141'592'654
1'000'000
0xdead'beaf
Make it known to the word regex of the cpp driver, so that numbers are
not split into separate tokens at the single-quotes.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We are going to add support for C++'s digit-separating single-quote and
the spaceship operator. By adding the test cases in this separate
commit, the effect on the word highlighting will become more obvious
as the features are implemented and the file cpp/expect is updated.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Generally, word regex can be written such that they match tokens
liberally and need not model the actual syntax because it can be assumed
that the regex will only be applied to syntactically correct text.
The regex for cpp (C/C++) is too liberal, though. It regards these
sequences as single tokens:
1+2
1.5-e+2+f
and the following amalgams as one token:
.l as in str.length
.f as in str.find
.e as in str.erase
Tighten the regex in the following way:
- Accept + and - only in one position in the exponent. + and - are no
longer regarded as the sign of a number and are treated by the
catcher-all that is not visible in the driver's regex.
- Accept a leading decimal point only when it is followed by a digit.
For readability, factor hex- and binary numbers into an own term.
As a drive-by, this fixes that floating point numbers such as 12E5
(with upper-case E) were split into two tokens.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The word regex is too loose and matches long streaks of characters
that should actually be separate tokens. Add these problematic test
cases. Separate the lines with text that will remain identical in the
pre- and post-image so that the diff algorithm will not lump removals
and additions of consecutive lines together. This makes the expected
output easier to read.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
8d96e7288f (t4034: bulk verify builtin word regex sanity, 2010-12-18)
added many tests with the intent to verify that operators consisting of
more than one symbol are kept together. These are tested by probing a
transition from, e.g., a!=b to x!=y, which results in the word-diff
[-a-]{+x+}!=[-b-]{+y+}
But that proves only that the letters and operators are separate tokens.
To prove that != is an unseparable token, we have to probe a transition
from, e.g., a=b to a!=b having a word-diff
a[-=-]{+!=+}b
that proves that the ! is not separate from the =.
In the post-image, add to or remove from operators a character that
turns it into another valid operator.
Change the identifiers used around operators such that the diff
algorithm does not have an incentive to match, e.g., a<b in one spot
in the pre-image with a<b elsewhere in the post-image.
Adjust the expected output to match the new differences. Notice that
there are some undesirable tokenizations around e, ., and -. This will
be addressed in a later change.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The builtin word regexes should be tested with some simple examples
against simple issues. Do this in bulk.
Mainly due to a lack of language knowledge and inspiration, most of
the test cases (cpp, csharp, java, objc, pascal, php, python, ruby)
are directly based off a C operator precedence table to verify that
all operators are split correctly. This means that they are probably
incomplete or inaccurate except for 'cpp' itself.
Still, they are good enough to already have uncovered a typo in the
python and ruby patterns.
'fortran' is based on my anecdotal knowledge of the DO10I parsing
rules, and thus probably useless. The rest (bibtex, html, tex) are an
ad-hoc test of what I consider important splits in those languages.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
