Still need to write tests for new syntax
and fix bugs that the tests find, but this
is a good check point.
All tests pass.
Compared against existing regexp:
benchmark old ns/op new ns/op delta
regexp.BenchmarkLiteral 1869 620 -66.83%
regexp.BenchmarkNotLiteral 9489 7823 -17.56%
regexp.BenchmarkMatchClass 10372 8386 -19.15%
regexp.BenchmarkMatchClass_InRange 10800 7750 -28.24%
regexp.BenchmarkReplaceAll 13492 8519 -36.86%
regexp.BenchmarkAnchoredLiteralShortNonMatch 747 339 -54.62%
regexp.BenchmarkAnchoredLiteralLongNonMatch 599 335 -44.07%
regexp.BenchmarkAnchoredShortMatch 2137 917 -57.09%
regexp.BenchmarkAnchoredLongMatch 2029 917 -54.81%
R=r, r
CC=golang-dev, sam.thorogood
https://golang.org/cl/4820046
Also reuse of *Regexp nodes.
I believe this is the end of the parser.
The only non-execution code that remains is
the code to expand x{3,5} into simpler operations.
R=sam.thorogood, r
CC=golang-dev
https://golang.org/cl/4629078
Still TODO: parsing optimizations
make_perl_groups.pl is copied with minimal modifications
(just to generate Go syntax instead of C++) from RE2.
Google Inc is "The RE2 Author" of that file and is one of
the Go Authors, so copyright changed to the Go Authors instead.
R=sam.thorogood, r, fvbommel, robert.hencke
CC=golang-dev
https://golang.org/cl/4612041
Parser is a work in progress but can populate most of the
interesting parts of the data structure, so a good checkpoint.
All the complicated Perl syntax is missing, as are various
important optimizations made during parsing to the
syntax tree.
The plan is that exp/regexp's API will mimic regexp,
and exp/regexp/syntax provides the parser directly
for programs that need it (and for implementing exp/regexp).
Once finished, exp/regexp will replace regexp.
R=r, sam.thorogood, kevlar, edsrzf
CC=golang-dev
https://golang.org/cl/4538123
