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Hana Dusíková
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added detection for pattern which starts with anchor so we can remove the for cycle in search (full solution to #95)
1 parent 4c97c59 commit ec4bd97

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3 files changed

+156
-4
lines changed

3 files changed

+156
-4
lines changed

‎include/ctre/evaluation.hpp‎

Lines changed: 5 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -4,6 +4,7 @@
44
#include "atoms.hpp"
55
#include "atoms_characters.hpp"
66
#include "atoms_unicode.hpp"
7+
#include "starts_with_anchor.hpp"
78
#include "utility.hpp"
89
#include "return_type.hpp"
910
#include "find_captures.hpp"
@@ -53,14 +54,16 @@ template <typename Iterator, typename EndIterator, typename Pattern>
5354
constexpr inline auto search_re(const Iterator begin, const EndIterator end, Pattern pattern) noexcept {
5455
using return_type = decltype(regex_results(std::declval<Iterator>(), find_captures(pattern)));
5556

57+
[[maybe_unused]] constexpr bool fixed = starts_with_anchor(ctll::list<Pattern>{});
58+
5659
auto it = begin;
57-
for (; end != it; ++it) {
60+
for (; end != it && !fixed; ++it) {
5861
if (auto out = evaluate(begin, it, end, return_type{}, ctll::list<start_mark, Pattern, end_mark, accept>())) {
5962
return out;
6063
}
6164
}
6265

63-
// in case the RE is empty
66+
// in case the RE is empty or fixed
6467
return evaluate(begin, it, end, return_type{}, ctll::list<start_mark, Pattern, end_mark, accept>());
6568
}
6669

‎include/ctre/starts_with_anchor.hpp‎

Lines changed: 73 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,73 @@
1+
#ifndef CTRE__STARTS_WITH_ANCHOR__HPP
2+
#define CTRE__STARTS_WITH_ANCHOR__HPP
3+
4+
namespace ctre {
5+
6+
template <typename... Content>
7+
constexpr bool starts_with_anchor(ctll::list<Content...>) noexcept {
8+
return false;
9+
}
10+
11+
template <typename... Content>
12+
constexpr bool starts_with_anchor(ctll::list<assert_begin, Content...>) noexcept {
13+
// yes! start anchor is here
14+
return true;
15+
}
16+
17+
template <typename... Options, typename... Content>
18+
constexpr bool starts_with_anchor(ctll::list<select<Options...>, Content...>) noexcept {
19+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
20+
return (starts_with_anchor(ctll::list<Options, Content...>{}) && ... && true);
21+
}
22+
23+
template <typename... Optional, typename... Content>
24+
constexpr bool starts_with_anchor(ctll::list<optional<Optional...>, Content...>) noexcept {
25+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
26+
return starts_with_anchor(ctll::list<Optional..., Content...>{}) && starts_with_anchor(ctll::list<Content...>{});
27+
}
28+
29+
template <typename... Optional, typename... Content>
30+
constexpr bool starts_with_anchor(ctll::list<lazy_optional<Optional...>, Content...>) noexcept {
31+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
32+
return starts_with_anchor(ctll::list<Optional..., Content...>{}) && starts_with_anchor(ctll::list<Content...>{});
33+
}
34+
35+
template <typename... Seq, typename... Content>
36+
constexpr bool starts_with_anchor(ctll::list<sequence<Seq...>, Content...>) noexcept {
37+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
38+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
39+
}
40+
41+
template <size_t A, size_t B, typename... Seq, typename... Content>
42+
constexpr bool starts_with_anchor(ctll::list<repeat<A, B, Seq...>, Content...>) noexcept {
43+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
44+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
45+
}
46+
47+
template <size_t A, size_t B, typename... Seq, typename... Content>
48+
constexpr bool starts_with_anchor(ctll::list<lazy_repeat<A, B, Seq...>, Content...>) noexcept {
49+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
50+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
51+
}
52+
53+
template <size_t A, size_t B, typename... Seq, typename... Content>
54+
constexpr bool starts_with_anchor(ctll::list<possessive_repeat<A, B, Seq...>, Content...>) noexcept {
55+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
56+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
57+
}
58+
59+
template <size_t Index, typename... Seq, typename... Content>
60+
constexpr bool starts_with_anchor(ctll::list<capture<Index, Seq...>, Content...>) noexcept {
61+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
62+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
63+
}
64+
65+
template <size_t Index, typename... Seq, typename... Content>
66+
constexpr bool starts_with_anchor(ctll::list<capture_with_name<Index, Seq...>, Content...>) noexcept {
67+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
68+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
69+
}
70+
71+
}
72+
73+
#endif

‎single-header/ctre.hpp‎

Lines changed: 78 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -2264,6 +2264,80 @@ template <auto V, auto... Value, auto... Name, typename... Ts, typename Paramete
22642264
#ifndef CTRE__EVALUATION__HPP
22652265
#define CTRE__EVALUATION__HPP
22662266

2267+
#ifndef CTRE__STARTS_WITH_ANCHOR__HPP
2268+
#define CTRE__STARTS_WITH_ANCHOR__HPP
2269+
2270+
namespace ctre {
2271+
2272+
template <typename... Content>
2273+
constexpr bool starts_with_anchor(ctll::list<Content...>) noexcept {
2274+
return false;
2275+
}
2276+
2277+
template <typename... Content>
2278+
constexpr bool starts_with_anchor(ctll::list<assert_begin, Content...>) noexcept {
2279+
// yes! start anchor is here
2280+
return true;
2281+
}
2282+
2283+
template <typename... Options, typename... Content>
2284+
constexpr bool starts_with_anchor(ctll::list<select<Options...>, Content...>) noexcept {
2285+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2286+
return (starts_with_anchor(ctll::list<Options, Content...>{}) && ... && true);
2287+
}
2288+
2289+
template <typename... Optional, typename... Content>
2290+
constexpr bool starts_with_anchor(ctll::list<optional<Optional...>, Content...>) noexcept {
2291+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2292+
return starts_with_anchor(ctll::list<Optional..., Content...>{}) && starts_with_anchor(ctll::list<Content...>{});
2293+
}
2294+
2295+
template <typename... Optional, typename... Content>
2296+
constexpr bool starts_with_anchor(ctll::list<lazy_optional<Optional...>, Content...>) noexcept {
2297+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2298+
return starts_with_anchor(ctll::list<Optional..., Content...>{}) && starts_with_anchor(ctll::list<Content...>{});
2299+
}
2300+
2301+
template <typename... Seq, typename... Content>
2302+
constexpr bool starts_with_anchor(ctll::list<sequence<Seq...>, Content...>) noexcept {
2303+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2304+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2305+
}
2306+
2307+
template <size_t A, size_t B, typename... Seq, typename... Content>
2308+
constexpr bool starts_with_anchor(ctll::list<repeat<A, B, Seq...>, Content...>) noexcept {
2309+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2310+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2311+
}
2312+
2313+
template <size_t A, size_t B, typename... Seq, typename... Content>
2314+
constexpr bool starts_with_anchor(ctll::list<lazy_repeat<A, B, Seq...>, Content...>) noexcept {
2315+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2316+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2317+
}
2318+
2319+
template <size_t A, size_t B, typename... Seq, typename... Content>
2320+
constexpr bool starts_with_anchor(ctll::list<possessive_repeat<A, B, Seq...>, Content...>) noexcept {
2321+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2322+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2323+
}
2324+
2325+
template <size_t Index, typename... Seq, typename... Content>
2326+
constexpr bool starts_with_anchor(ctll::list<capture<Index, Seq...>, Content...>) noexcept {
2327+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2328+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2329+
}
2330+
2331+
template <size_t Index, typename... Seq, typename... Content>
2332+
constexpr bool starts_with_anchor(ctll::list<capture_with_name<Index, Seq...>, Content...>) noexcept {
2333+
// check if all options starts with anchor or if they are empty, there is an anchor behind them
2334+
return starts_with_anchor(ctll::list<Seq..., Content...>{});
2335+
}
2336+
2337+
}
2338+
2339+
#endif
2340+
22672341
#ifndef CTRE__RETURN_TYPE__HPP
22682342
#define CTRE__RETURN_TYPE__HPP
22692343

@@ -3239,14 +3313,16 @@ template <typename Iterator, typename EndIterator, typename Pattern>
32393313
constexpr inline auto search_re(const Iterator begin, const EndIterator end, Pattern pattern) noexcept {
32403314
using return_type = decltype(regex_results(std::declval<Iterator>(), find_captures(pattern)));
32413315

3316+
[[maybe_unused]] constexpr bool fixed = starts_with_anchor(ctll::list<Pattern>{});
3317+
32423318
auto it = begin;
3243-
for (; end != it; ++it) {
3319+
for (; end != it && !fixed; ++it) {
32443320
if (auto out = evaluate(begin, it, end, return_type{}, ctll::list<start_mark, Pattern, end_mark, accept>())) {
32453321
return out;
32463322
}
32473323
}
32483324

3249-
// in case the RE is empty
3325+
// in case the RE is empty or fixed
32503326
return evaluate(begin, it, end, return_type{}, ctll::list<start_mark, Pattern, end_mark, accept>());
32513327
}
32523328

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