Add query parser class

YACReaderLibrary/db/query_parser.h

@@ -0,0 +1,63 @@
+#ifndef QUERY_PARSER_H
+#define QUERY_PARSER_H
+
+#include "lexertl/generator.hpp"
+#include "lexertl/iterator.hpp"
+
+#include <map>
+#include <QSqlQuery>
+#include <string>
+#include <vector>
+
+class QSqlQuery;
+
+class QueryParser {
+public:
+
+    enum class TokenType {eof, opcode, atWord, word, quotedWord, space};
+
+    struct TreeNode {
+        std::string t;
+        std::vector<TreeNode> children;
+
+        int buildSqlString(std::string& sqlString, int bindPosition = 0) const;
+        int bindValues(QSqlQuery& selectQuery, int bindPosition = 0) const;
+    };
+
+    explicit QueryParser();
+    TreeNode parse(const std::string& expr);
+
+private:
+    static std::string toLower(const std::string& string);
+
+    std::string token(bool advance = false);
+    std::string lcaseToken(bool advance = false);
+    TokenType tokenType();
+    bool isEof() const;
+    void advance();
+
+    template<typename First, typename ... T>
+    static bool isIn(First &&first, T && ... t) {return ((first == t) || ...);}
+
+    enum class FieldType {unknown, numeric, text, boolean, date};
+    static FieldType fieldType(const std::string& str);
+
+    void tokenize (const std::string& expr);
+    static std::string join(const std::vector<std::string>& strings, const std::string& delim);
+    static std::vector<std::string> split(const std::string& string, char delim);
+
+    TreeNode orExpression();
+    TreeNode andExpression();
+    TreeNode notExpression();
+    TreeNode locationExpression();
+    TreeNode baseToken();
+
+    lexertl::rules lexScanner;
+    lexertl::state_machine sm;
+    lexertl::siterator iter;
+    const lexertl::siterator end;
+
+    static const std::map<FieldType, std::vector<std::string>> fieldNames;
+};
+
+#endif // QUERY_PARSER_H