Add Regexp.linear_time? (#6901)

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TSUYUSATO Kitsune 2022-12-14 12:57:14 +09:00 committed by GitHub
parent fe3cbc61c8
commit fbedadb61f
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Notes: git 2022-12-14 03:57:33 +00:00
Merged-By: makenowjust <make.just.on@gmail.com>
4 changed files with 59 additions and 1 deletions

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@ -854,6 +854,8 @@ OnigPosition onig_search_gpos(OnigRegex, const OnigUChar* str, const OnigUChar*
ONIG_EXTERN
OnigPosition onig_match(OnigRegex, const OnigUChar* str, const OnigUChar* end, const OnigUChar* at, OnigRegion* region, OnigOptionType option);
ONIG_EXTERN
int onig_check_linear_time(OnigRegex reg);
ONIG_EXTERN
OnigRegion* onig_region_new(void);
ONIG_EXTERN
void onig_region_init(OnigRegion* region);

34
re.c
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@ -4194,6 +4194,39 @@ rb_reg_s_union_m(VALUE self, VALUE args)
return rb_reg_s_union(self, args);
}
/*
* call-seq:
* Regexp.linear_time?(re)
* Regexp.linear_time?(string, options = 0)
*
* Returns +true+ if matching against <tt>re</tt> can be
* done in linear time to the input string.
*
* Regexp.linear_time?(/re/) # => true
*
*/
static VALUE
rb_reg_s_linear_time_p(int argc, VALUE *argv, VALUE self)
{
VALUE re;
VALUE src, opts = Qundef, n_flag = Qundef, kwargs;
rb_scan_args(argc, argv, "12:", &src, &opts, &n_flag, &kwargs);
if (RB_TYPE_P(src, T_REGEXP)) {
re = src;
if (opts != Qnil) {
rb_warn("flags ignored");
}
}
else {
re = rb_class_new_instance(argc, argv, rb_cRegexp);
}
rb_reg_check(re);
return RBOOL(onig_check_linear_time(RREGEXP_PTR(re)));
}
/* :nodoc: */
static VALUE
rb_reg_init_copy(VALUE copy, VALUE re)
@ -4571,6 +4604,7 @@ Init_Regexp(void)
rb_define_singleton_method(rb_cRegexp, "union", rb_reg_s_union_m, -2);
rb_define_singleton_method(rb_cRegexp, "last_match", rb_reg_s_last_match, -1);
rb_define_singleton_method(rb_cRegexp, "try_convert", rb_reg_s_try_convert, 1);
rb_define_singleton_method(rb_cRegexp, "linear_time?", rb_reg_s_linear_time_p, -1);
rb_define_method(rb_cRegexp, "initialize", rb_reg_initialize_m, -1);
rb_define_method(rb_cRegexp, "initialize_copy", rb_reg_init_copy, 1);

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@ -694,7 +694,21 @@ unexpected_bytecode_error:
bytecode_error:
return ONIGERR_UNDEFINED_BYTECODE;
}
#endif /* USE_MATCH_CACHE */
#else /* USE_MATCH_CACHE */
static OnigPosition count_num_cache_opcode(regex_t* reg, long* num, long* table_size)
{
*num = NUM_CACHE_OPCODE_FAIL;
return 0;
}
#endif
extern int
onig_check_linear_time(OnigRegexType* reg)
{
long num = 0, table_size = 0;
count_num_cache_opcode(reg, &num, &table_size);
return num != NUM_CACHE_OPCODE_FAIL;
}
extern void
onig_region_clear(OnigRegion* region)

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@ -1696,4 +1696,12 @@ class TestRegexp < Test::Unit::TestCase
assert_nil(/^a*b?a*$/ =~ "a" * 1000000 + "x")
end;
end
def test_linear_time_p
assert_send [Regexp, :linear_time?, /a/]
assert_send [Regexp, :linear_time?, 'a']
assert_send [Regexp, :linear_time?, 'a', Regexp::IGNORECASE]
assert_not_send [Regexp, :linear_time?, /(a)\1/]
assert_not_send [Regexp, :linear_time?, "(a)\\1"]
end
end