Use common filter parser for collection and playlist

src/filterparser/filterparser.h

@@ -0,0 +1,76 @@
+/*
+ * Strawberry Music Player
+ * This file was part of Clementine.
+ * Copyright 2012, David Sansome <me@davidsansome.com>
+ * Copyright 2018-2024, Jonas Kvinge <jonas@jkvinge.net>
+ * Copyright 2023, Daniel Ostertag <daniel.ostertag@dakes.de>
+ *
+ * Strawberry is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Strawberry is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Strawberry.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef FILTERPARSER_H
+#define FILTERPARSER_H
+
+#include "config.h"
+
+#include <QString>
+
+class FilterTree;
+
+// A utility class to parse search filter strings into a decision tree
+// that can decide whether a song matches the filter.
+//
+// Here's a grammar describing the filters we expect:
+//   　expr      ::= or-group
+//     or-group  ::= and-group ('OR' and-group)*
+//     and-group ::= sexpr ('AND' sexpr)*
+//     sexpr     ::= sterm | '-' sexpr | '(' or-group ')'
+//     sterm     ::= col ':' sstring | sstring
+//     sstring   ::= prefix? string
+//     string    ::= [^:-()" ]+ | '"' [^"]+ '"'
+//     prefix    ::= '=' | '<' | '>' | '<=' | '>='
+//     col       ::= "title" | "artist" | ...
+class FilterParser {
+ public:
+  explicit FilterParser(const QString &filter_string);
+
+  FilterTree *parse();
+
+  static QString ToolTip();
+
+ protected:
+  void advance();
+  // Check if iter is at the start of 'AND' if so, step over it and return true if not, return false and leave iter where it was
+  bool checkAnd();
+  // Check if iter is at the start of 'OR'
+  bool checkOr(const bool step_over = true);
+
+  FilterTree *parseOrGroup();
+  FilterTree *parseAndGroup();
+  FilterTree *parseSearchExpression();
+  FilterTree *parseSearchTerm();
+
+  FilterTree *createSearchTermTreeNode(const QString &column, const QString &prefix, const QString &value) const;
+
+  static qint64 ParseTime(const QString &time_str);
+  static float ParseRating(const QString &rating_str);
+
+  const QString filter_string_;
+  QString::const_iterator iter_;
+  QString::const_iterator end_;
+  QString buf_;
+};
+
+#endif  // FILTERPARSER_H