Add fuzzy string matching to quick open search

Co-authored-by: sam <samsface@gmail.com>

1 files changed, 101 insertions, 0 deletions

diff --git a/core/string/fuzzy_search.h b/core/string/fuzzy_search.h
new file mode 100644
index 0000000000..5d8ed813c7
--- /dev/null
+++ b/core/string/fuzzy_search.h
@@ -0,0 +1,101 @@
+/**************************************************************************/
+/*  fuzzy_search.h                                                        */
+/**************************************************************************/
+/*                         This file is part of:                          */
+/*                             GODOT ENGINE                               */
+/*                        https://godotengine.org                         */
+/**************************************************************************/
+/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
+/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur.                  */
+/*                                                                        */
+/* Permission is hereby granted, free of charge, to any person obtaining  */
+/* a copy of this software and associated documentation files (the        */
+/* "Software"), to deal in the Software without restriction, including    */
+/* without limitation the rights to use, copy, modify, merge, publish,    */
+/* distribute, sublicense, and/or sell copies of the Software, and to     */
+/* permit persons to whom the Software is furnished to do so, subject to  */
+/* the following conditions:                                              */
+/*                                                                        */
+/* The above copyright notice and this permission notice shall be         */
+/* included in all copies or substantial portions of the Software.        */
+/*                                                                        */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,        */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF     */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY   */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,   */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE      */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
+/**************************************************************************/
+
+#ifndef FUZZY_SEARCH_H
+#define FUZZY_SEARCH_H
+
+#include "core/variant/variant.h"
+
+class FuzzyTokenMatch;
+
+struct FuzzySearchToken {
+	int idx = -1;
+	String string;
+
+	bool try_exact_match(FuzzyTokenMatch &p_match, const String &p_target, int p_offset) const;
+	bool try_fuzzy_match(FuzzyTokenMatch &p_match, const String &p_target, int p_offset, int p_miss_budget) const;
+};
+
+class FuzzyTokenMatch {
+	friend struct FuzzySearchToken;
+	friend class FuzzySearchResult;
+	friend class FuzzySearch;
+
+	int matched_length = 0;
+	int token_length = 0;
+	int token_idx = -1;
+	Vector2i interval = Vector2i(-1, -1); // x and y are both inclusive indices.
+
+	void add_substring(int p_substring_start, int p_substring_length);
+	bool intersects(const Vector2i &p_other_interval) const;
+	bool is_case_insensitive(const String &p_original, const String &p_adjusted) const;
+	int get_miss_count() const { return token_length - matched_length; }
+
+public:
+	int score = 0;
+	Vector<Vector2i> substrings; // x is start index, y is length.
+};
+
+class FuzzySearchResult {
+	friend class FuzzySearch;
+
+	int miss_budget = 0;
+	Vector2i match_interval = Vector2i(-1, -1);
+
+	bool can_add_token_match(const FuzzyTokenMatch &p_match) const;
+	void score_token_match(FuzzyTokenMatch &p_match, bool p_case_insensitive) const;
+	void add_token_match(const FuzzyTokenMatch &p_match);
+	void maybe_apply_score_bonus();
+
+public:
+	String target;
+	int score = 0;
+	int dir_index = -1;
+	Vector<FuzzyTokenMatch> token_matches;
+};
+
+class FuzzySearch {
+	Vector<FuzzySearchToken> tokens;
+
+	void sort_and_filter(Vector<FuzzySearchResult> &p_results) const;
+
+public:
+	int start_offset = 0;
+	bool case_sensitive = false;
+	int max_results = 100;
+	int max_misses = 2;
+	bool allow_subsequences = true;
+
+	void set_query(const String &p_query);
+	bool search(const String &p_target, FuzzySearchResult &p_result) const;
+	void search_all(const PackedStringArray &p_targets, Vector<FuzzySearchResult> &p_results) const;
+};
+
+#endif // FUZZY_SEARCH_H