Sketched rough parser code construction including some SQL AST classes.

core/SqlParser.cpp

@@ -0,0 +1,75 @@
+#include "SqlParser.h"
+#include "SqlAstSelect.h"
+#include <unordered_map>
+
+using namespace SqlAst;
+
+Keyword isKeyword(QString symbol)
+{
+	static std::unordered_map<std::string, Keyword> lookup_map = {
+		{ "as",     Keyword::As },
+		{ "by",     Keyword::By },
+		{ "delete", Keyword::Delete },
+		{ "from",   Keyword::From },
+		{ "group",  Keyword::Group },
+		{ "insert", Keyword::Insert },
+		{ "order",  Keyword::Order },
+		{ "select", Keyword::Select },
+		{ "update", Keyword::Update },
+		{ "where",  Keyword::Where }
+	};
+
+	auto res = lookup_map.find(symbol.toLower().toUtf8().data());
+	if (res != lookup_map.end())
+		return res->second;
+	else
+		return Keyword::NotAKeyword;
+}
+
+
+SqlParser::SqlParser(SqlLexer &lexer)
+	: lexer(lexer)
+{
+
+}
+
+void SqlParser::parse()
+{
+	// Basic algo:
+	// LOOP
+	//   GET token
+	//   IF NOT try_reduce(token)
+	//   THEN SHIFT
+	// END LOOP
+	while (1) {
+		SqlToken token = lexer.nextBasicToken();
+		if (token.ok) {
+			if (token.tokenType == BasicTokenType::Symbol) {
+				Keyword kw = isKeyword(token.out);
+				switch (kw) {
+				case Keyword::Select:
+					parseSelect(*this);
+					break;
+
+				case Keyword::NotAKeyword:
+				default:
+					// unexpected
+					break;
+				}
+			}
+		}
+		else {
+			// error during lexical analysis, need to recover
+
+		}
+	}
+}
+
+
+
+
+//bool try_reduce(SqkToken token)
+//{
+//	// what state are we in? what are we expecting
+
+//}