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