forked from PuqiAR/Fig-TreeWalker
[Feat] 详细区分左值(LvObject)与右值(RvObject -> ObjectPtr)
[Impl] 重构evaluator.cpp + hpp 全部 [Feat] 增加对于IndexExpr的解析 [Fix][Impl] 现在点运算符不由BinaryExpr负责,增加MemberExpr,单独实现解析 [Impl] 项目目录全部翻修, src/目录下单独文件夹放置每一个模块
This commit is contained in:
937
src/Parser/parser.cpp
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937
src/Parser/parser.cpp
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@@ -0,0 +1,937 @@
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#include <Parser/parser.hpp>
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namespace Fig
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{
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// Operator : pair<LeftBindingPower, RightBindingPower>
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const std::unordered_map<Ast::Operator, std::pair<Parser::Precedence, Parser::Precedence>> Parser::opPrecedence = {
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// 算术
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{Ast::Operator::Add, {10, 11}},
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{Ast::Operator::Subtract, {10, 11}},
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{Ast::Operator::Multiply, {20, 21}},
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{Ast::Operator::Divide, {20, 21}},
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{Ast::Operator::Modulo, {20, 21}},
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{Ast::Operator::Power, {30, 29}},
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// 逻辑
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{Ast::Operator::And, {5, 6}},
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{Ast::Operator::Or, {4, 5}},
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{Ast::Operator::Not, {30, 31}}, // 一元
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// 比较
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{Ast::Operator::Equal, {7, 8}},
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{Ast::Operator::NotEqual, {7, 8}},
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{Ast::Operator::Less, {8, 9}},
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{Ast::Operator::LessEqual, {8, 9}},
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{Ast::Operator::Greater, {8, 9}},
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{Ast::Operator::GreaterEqual, {8, 9}},
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// 位运算
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{Ast::Operator::BitAnd, {6, 7}},
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{Ast::Operator::BitOr, {4, 5}},
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{Ast::Operator::BitXor, {5, 6}},
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{Ast::Operator::BitNot, {30, 31}}, // 一元
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{Ast::Operator::ShiftLeft, {15, 16}},
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{Ast::Operator::ShiftRight, {15, 16}},
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{Ast::Operator::Assign, {2, 1}}, // 右结合
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// 海象运算符
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// {Ast::Operator::Walrus, {2, 1}}, // 右结合
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// // 点运算符
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// {Ast::Operator::Dot, {40, 41}},
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};
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Ast::VarDef Parser::__parseVarDef(bool isPublic)
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{
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// entry: current is keyword `var` or `const`
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bool isConst = (currentToken().getType() == TokenType::Const ? true : false);
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next();
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expect(TokenType::Identifier);
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FString name = currentToken().getValue();
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next();
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FString tiName = ValueType::Any.name;
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bool hasSpecificType = false;
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if (isThis(TokenType::Colon)) // :
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{
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expectPeek(TokenType::Identifier, FString(u8"Type name"));
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next();
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tiName = currentToken().getValue();
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next();
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hasSpecificType = true;
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}
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if (isThis(TokenType::Semicolon))
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{
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next(); // consume `;`, no using expectConsume here cause we don't need to check again
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return makeAst<Ast::VarDefAst>(isPublic, isConst, name, tiName, nullptr);
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}
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if (!isThis(TokenType::Assign) and !isThis(TokenType::Walrus)) expect(TokenType::Assign, u8"assign or walrus");
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if (isThis(TokenType::Walrus))
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{
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if (hasSpecificType) throwAddressableError<SyntaxError>(FStringView(u8""));
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tiName = Parser::varDefTypeFollowed;
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}
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next();
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Ast::Expression exp = parseExpression(0);
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expectSemicolon();
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return makeAst<Ast::VarDefAst>(isPublic, isConst, name, tiName, exp);
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}
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ObjectPtr Parser::__parseValue()
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{
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FString _val = currentToken().getValue();
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if (currentToken().getType() == TokenType::LiteralNumber)
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{
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if (_val.contains(u8'.') || _val.contains(u8'e'))
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{
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// 非整数
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ValueType::DoubleClass d;
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try
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{
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d = std::stod(_val.toBasicString());
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}
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catch (...)
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{
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throwAddressableError<SyntaxError>(FStringView(u8"Illegal number literal"));
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}
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return std::make_shared<Object>(d);
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}
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else
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{
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// 整数
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ValueType::IntClass i;
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try
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{
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i = std::stoi(_val.toBasicString());
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}
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catch (...)
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{
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throwAddressableError<SyntaxError>(FStringView(u8"Illegal number literal"));
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}
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return std::make_shared<Object>(i);
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}
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}
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else if (currentToken().getType() == TokenType::LiteralString)
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{
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return std::make_shared<Object>(_val);
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}
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else if (currentToken().getType() == TokenType::LiteralBool)
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{
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return std::make_shared<Object>((_val == u8"true" ? true : false));
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}
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else if (currentToken().getType() == TokenType::LiteralNull)
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{
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return Object::getNullInstance();
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}
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else
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{
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throw std::runtime_error(std::string("Internal Error at: ") + std::string(__func__));
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}
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}
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Ast::ValueExpr Parser::__parseValueExpr()
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{
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return makeAst<Ast::ValueExprAst> (__parseValue());
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}
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Ast::FunctionParameters Parser::__parseFunctionParameters()
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{
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// entry: current is Token::LeftParen
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// stop: current is `)` next one
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// *note: must called when parsing function
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next(); // skip `(`
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Ast::FunctionParameters::PosParasType pp;
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Ast::FunctionParameters::DefParasType dp;
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while (true)
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{
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if (isThis(TokenType::RightParen))
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{
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next();
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return Ast::FunctionParameters(pp, dp);
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}
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expect(TokenType::Identifier, FString(u8"Identifier or `)`")); // check current
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FString pname = currentToken().getValue();
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next(); // skip pname
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if (isThis(TokenType::Assign)) // =
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{
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next();
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dp.push_back({pname, {ValueType::Any.name, parseExpression(0, TokenType::Comma)}});
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if (isThis(TokenType::Comma))
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{
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next(); // only skip `,` when it's there
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}
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}
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else if (isThis(TokenType::Colon)) // :
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{
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next(); // skip `:`
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expect(TokenType::Identifier, FString(u8"Type name"));
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FString ti(currentToken().getValue());
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next(); // skip type name
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if (isThis(TokenType::Assign)) // =
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{
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next(); // skip `=`
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dp.push_back({pname, {ti, parseExpression(0, TokenType::Comma)}});
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if (isThis(TokenType::Comma))
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{
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next(); // only skip `,` when it's there
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}
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}
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else
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{
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pp.push_back({pname, ti});
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if (isThis(TokenType::Comma))
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{
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next(); // only skip `,` when it's there
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}
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}
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}
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else
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{
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pp.push_back({pname, ValueType::Any.name});
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if (isThis(TokenType::Comma))
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{
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next(); // only skip `,` when it's there
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}
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}
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}
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}
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Ast::FunctionDef Parser::__parseFunctionDef(bool isPublic)
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{
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FString funcName = currentToken().getValue();
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next();
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expect(TokenType::LeftParen);
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Ast::FunctionParameters params = __parseFunctionParameters();
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FString retTiName = ValueType::Any.name;
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if (isThis(TokenType::RightArrow)) // ->
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{
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next(); // skip `->`
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expect(TokenType::Identifier);
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retTiName = currentToken().getValue();
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next(); // skip return type
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}
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expect(TokenType::LeftBrace);
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Ast::BlockStatement body = __parseBlockStatement();
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return makeAst<Ast::FunctionDefSt>(funcName, params, isPublic, retTiName, body);
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}
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Ast::StructDef Parser::__parseStructDef(bool isPublic)
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{
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// entry: current is struct name
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FString structName = currentToken().getValue();
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next();
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expect(TokenType::LeftBrace, u8"struct body");
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next();
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bool braceClosed = false;
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/*
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public name
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public const name
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public final name
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const name
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final name
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name
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*/
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auto __parseStructField = [this](bool isPublic) -> Ast::StructDefField {
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AccessModifier am = AccessModifier::Normal;
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FString fieldName;
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if (isThis(TokenType::Identifier))
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{
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fieldName = currentToken().getValue();
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next();
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am = (isPublic ? AccessModifier::Public : AccessModifier::Normal);
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}
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else if (isThis(TokenType::Const))
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{
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next();
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expect(TokenType::Identifier, u8"field name");
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fieldName = currentToken().getValue();
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am = (isPublic ? AccessModifier::PublicConst : AccessModifier::Const);
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}
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else
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{
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throwAddressableError<SyntaxError>(FStringView(std::format("expect field name or field attribute")));
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}
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FString tiName = ValueType::Any.name;
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if (isThis(TokenType::Colon))
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{
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next();
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expect(TokenType::Identifier, u8"type name");
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tiName = currentToken().getValue();
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next();
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}
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Ast::Expression initExpr = nullptr;
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if (isThis(TokenType::Assign))
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{
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next();
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if (isEOF()) throwAddressableError<SyntaxError>(FStringView(u8"expect an expression"));
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initExpr = parseExpression(0);
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}
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expectSemicolon();
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return Ast::StructDefField(am, fieldName, tiName, initExpr);
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};
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std::vector<Ast::Statement> stmts;
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std::vector<Ast::StructDefField> fields;
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while (!isEOF())
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{
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if (isThis(TokenType::RightBrace))
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{
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braceClosed = true;
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next(); // consume `}`
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break;
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}
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if (isThis(TokenType::Identifier))
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{
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fields.push_back(__parseStructField(false));
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}
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else if (isThis(TokenType::Public))
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{
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if (isNext(TokenType::Const))
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{
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next();
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fields.push_back(__parseStructField(true));
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}
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else if (isNext(TokenType::Function))
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{
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next(); // consume `public`
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next(); // consume `function`
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stmts.push_back(__parseFunctionDef(true));
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}
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else if (isNext(TokenType::Struct))
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{
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next(); // consume `public`
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next(); // consume `struct`
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stmts.push_back(__parseStructDef(true));
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}
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else if (isNext(TokenType::Identifier))
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{
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next(); // consume `public`
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fields.push_back(__parseStructField(true));
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}
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else
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{
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throwAddressableError<SyntaxError>(FStringView("Invalid syntax"));
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}
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}
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else if (isThis(TokenType::Function))
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{
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next();
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stmts.push_back(__parseFunctionDef(false));
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}
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else if (isThis(TokenType::Struct))
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{
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next(); // consume `struct`
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stmts.push_back(__parseStructDef(false));
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}
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else if (isThis(TokenType::Const))
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{
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fields.push_back(__parseStructField(false));
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}
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else if (isThis(TokenType::Variable))
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{
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throwAddressableError<SyntaxError>(FStringView("Variables are not allowed to be defined within a structure."));
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}
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else
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{
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throwAddressableError<SyntaxError>(FStringView("Invalid syntax"));
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}
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}
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if (!braceClosed)
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{
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throwAddressableError<SyntaxError>(FStringView("braces are not closed"));
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}
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return makeAst<Ast::StructDefSt>(isPublic, structName, fields, makeAst<Ast::BlockStatementAst>(stmts));
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}
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Ast::Statement Parser::__parseStatement()
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{
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Ast::Statement stmt;
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if (isThis(TokenType::EndOfFile)) { return makeAst<Ast::EofStmt>(); }
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if (isThis(TokenType::Public))
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{
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next(); // consume `public`
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if (isThis(TokenType::Variable) || isThis(TokenType::Const))
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{
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stmt = __parseVarDef(true);
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}
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else if (isThis(TokenType::Function) and isNext(TokenType::Identifier))
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{
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next();
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stmt = __parseFunctionDef(true);
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}
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else if (isThis(TokenType::Struct))
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{
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stmt = __parseStructDef(true);
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}
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else
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{
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throwAddressableError<SyntaxError>(FStringView(u8"Expected `var`, `const`, `function` or `struct` after `public`"));
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}
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}
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else if (isThis(TokenType::Variable) || isThis(TokenType::Const))
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{
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stmt = __parseVarDef(false);
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}
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else if (isThis(TokenType::Function) and isNext(TokenType::Identifier))
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{
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next();
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stmt = __parseFunctionDef(false);
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}
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else if (isThis(TokenType::Struct))
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{
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expectPeek(TokenType::Identifier, u8"struct name");
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next();
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stmt = __parseStructDef(false);
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}
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else if (isThis(TokenType::If))
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{
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stmt = __parseIf();
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}
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else if (isThis(TokenType::Else))
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{
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throwAddressableError<SyntaxError>(FStringView(u8"`else` without matching `if`"));
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}
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else if (isThis(TokenType::LeftBrace))
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{
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stmt = __parseBlockStatement();
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}
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else if (isThis(TokenType::While))
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{
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stmt = __parseWhile();
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}
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else if (isThis(TokenType::For))
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{
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stmt = __parseFor();
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}
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else if (isThis(TokenType::Return))
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{
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stmt = __parseReturn();
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}
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else if (isThis(TokenType::Break))
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{
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stmt = __parseBreak();
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}
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else if (isThis(TokenType::Continue))
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{
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stmt = __parseContinue();
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}
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else
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{
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// expression statement
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Ast::Expression exp = parseExpression(0);
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expectSemicolon();
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stmt = makeAst<Ast::ExpressionStmtAst>(exp);
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}
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return stmt;
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}
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Ast::BlockStatement Parser::__parseBlockStatement()
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{
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// entry: current is `{`
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// stop: current is `}` next one
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next(); // consume `{`
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std::vector<Ast::Statement> stmts;
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while (true)
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{
|
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if (isThis(TokenType::RightBrace))
|
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{
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next();
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return makeAst<Ast::BlockStatementAst>(stmts);
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}
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stmts.push_back(__parseStatement());
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}
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}
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Ast::If Parser::__parseIf()
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{
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// entry: current is `if`
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next(); // consume `if`
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Ast::Expression condition;
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if (isThis(TokenType::LeftParen))
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{
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next(); // consume `(`
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condition = parseExpression(0, TokenType::RightParen);
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expect(TokenType::RightParen);
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next(); // consume `)`
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}
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else
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{
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condition = parseExpression(0);
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}
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// parenthesis is not required
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expect(TokenType::LeftBrace); // {
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Ast::BlockStatement body = __parseBlockStatement();
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std::vector<Ast::ElseIf> elifs;
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Ast::Else els = nullptr;
|
||||
while (isThis(TokenType::Else))
|
||||
{
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||||
next(); // consume `else`
|
||||
if (isThis(TokenType::If))
|
||||
{
|
||||
// else if
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||||
next(); // consume `if`
|
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Ast::Expression elifCondition = parseExpression(0);
|
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expect(TokenType::LeftBrace); // {
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Ast::BlockStatement elifBody = __parseBlockStatement();
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elifs.push_back(makeAst<Ast::ElseIfSt>(elifCondition, elifBody));
|
||||
}
|
||||
else
|
||||
{
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expect(TokenType::LeftBrace); // {
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Ast::BlockStatement elseBody = __parseBlockStatement();
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els = makeAst<Ast::ElseSt>(elseBody);
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break;
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||||
}
|
||||
}
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return makeAst<Ast::IfSt>(condition, body, elifs, els);
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}
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Ast::While Parser::__parseWhile()
|
||||
{
|
||||
// entry: current is `while`
|
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next(); // consume `while`
|
||||
Ast::Expression condition = parseExpression(0);
|
||||
expect(TokenType::LeftBrace); // {
|
||||
Ast::BlockStatement body = __parseBlockStatement();
|
||||
return makeAst<Ast::WhileSt>(condition, body);
|
||||
}
|
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Ast::Statement Parser::__parseIncrementStatement()
|
||||
{
|
||||
// allowed：
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||||
// 1. assignment：i = 1, i += 1
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||||
// 2. expression stmt：i++, foo()
|
||||
// ❌ not allowed：if/while/for/block stmt
|
||||
|
||||
if (isThis(TokenType::LeftBrace))
|
||||
{
|
||||
throwAddressableError<SyntaxError>(u8"BlockStatement cannot be used as for loop increment");
|
||||
}
|
||||
|
||||
if (isThis(TokenType::If) || isThis(TokenType::While) || isThis(TokenType::For) || isThis(TokenType::Return) || isThis(TokenType::Break) || isThis(TokenType::Continue))
|
||||
{
|
||||
throwAddressableError<SyntaxError>(u8"Control flow statements cannot be used as for loop increment");
|
||||
}
|
||||
|
||||
return __parseStatement();
|
||||
}
|
||||
Ast::For Parser::__parseFor()
|
||||
{
|
||||
// entry: current is `for`
|
||||
// TODO: support enumeration
|
||||
next(); // consume `for`
|
||||
bool paren = isThis(TokenType::LeftParen);
|
||||
if (paren)
|
||||
next(); // consume `(`
|
||||
// support 3-part for loop
|
||||
// for init; condition; increment {}
|
||||
Ast::Statement initStmt = __parseStatement(); // auto check ``
|
||||
Ast::Expression condition = parseExpression(0);
|
||||
expectSemicolon(); // auto consume `;`
|
||||
|
||||
Ast::Statement incrementStmt = nullptr;
|
||||
if (!isThis(paren ? TokenType::RightParen : TokenType::LeftBrace)) // need parse increment?
|
||||
{
|
||||
auto guard = disableSemicolon();
|
||||
incrementStmt = __parseIncrementStatement();
|
||||
} // after parse increment, semicolon check state restored
|
||||
if (paren)
|
||||
expectConsume(TokenType::RightParen); // consume `)` if has `(`
|
||||
expect(TokenType::LeftBrace); // {
|
||||
Ast::BlockStatement body = __parseBlockStatement(); // auto consume `}`
|
||||
return makeAst<Ast::ForSt>(initStmt, condition, incrementStmt, body);
|
||||
}
|
||||
Ast::Return Parser::__parseReturn()
|
||||
{
|
||||
// entry: current is `return`
|
||||
next(); // consume `return`
|
||||
Ast::Expression retValue = parseExpression(0);
|
||||
expectSemicolon();
|
||||
return makeAst<Ast::ReturnSt>(retValue);
|
||||
}
|
||||
Ast::Continue Parser::__parseContinue()
|
||||
{
|
||||
// entry: current is `continue`
|
||||
next(); // consume `continue`
|
||||
expectSemicolon();
|
||||
return makeAst<Ast::ContinueSt>();
|
||||
}
|
||||
Ast::Break Parser::__parseBreak()
|
||||
{
|
||||
// entry: current is `break`
|
||||
next(); // consume `break`
|
||||
expectSemicolon();
|
||||
return makeAst<Ast::BreakSt>();
|
||||
}
|
||||
|
||||
Ast::VarExpr Parser::__parseVarExpr(FString name)
|
||||
{
|
||||
return makeAst<Ast::VarExprAst>(name);
|
||||
}
|
||||
|
||||
Ast::UnaryExpr Parser::__parsePrefix(Ast::Operator op, Precedence bp)
|
||||
{
|
||||
return makeAst<Ast::UnaryExprAst>(op, parseExpression(bp));
|
||||
}
|
||||
Ast::BinaryExpr Parser::__parseInfix(Ast::Expression lhs, Ast::Operator op, Precedence bp)
|
||||
{
|
||||
return makeAst<Ast::BinaryExprAst>(lhs, op, parseExpression(bp));
|
||||
}
|
||||
|
||||
Ast::Expression Parser::__parseCall(Ast::Expression callee)
|
||||
{
|
||||
next(); // consume '('
|
||||
std::vector<Ast::Expression> args;
|
||||
|
||||
if (!isThis(TokenType::RightParen))
|
||||
{
|
||||
while (true)
|
||||
{
|
||||
args.push_back(parseExpression(0, TokenType::Comma, TokenType::RightParen));
|
||||
|
||||
if (isThis(TokenType::Comma))
|
||||
{
|
||||
next();
|
||||
continue;
|
||||
}
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
expect(TokenType::RightParen);
|
||||
next(); // consume ')'
|
||||
|
||||
return makeAst<Ast::FunctionCallExpr>(callee, Ast::FunctionArguments(args));
|
||||
}
|
||||
|
||||
Ast::ListExpr Parser::__parseListExpr()
|
||||
{
|
||||
// entry: current is `[`
|
||||
next(); // consume `[`
|
||||
std::vector<Ast::Expression> val;
|
||||
while (!isThis(TokenType::RightBracket))
|
||||
{
|
||||
val.push_back(parseExpression(0, TokenType::RightBracket, TokenType::Comma));
|
||||
if (isThis(TokenType::Comma))
|
||||
{
|
||||
next(); // consume `,`
|
||||
}
|
||||
}
|
||||
expect(TokenType::RightBracket);
|
||||
next(); // consume `]`
|
||||
return makeAst<Ast::ListExprAst>(val);
|
||||
}
|
||||
|
||||
Ast::MapExpr Parser::__parseMapExpr()
|
||||
{
|
||||
// entry: current is `{`
|
||||
next(); // consume `{`
|
||||
std::map<FString, Ast::Expression> val;
|
||||
while (!isThis(TokenType::RightBrace))
|
||||
{
|
||||
expect(TokenType::Identifier, FString(u8"key (identifier)"));
|
||||
FString key = currentToken().getValue();
|
||||
if (val.contains(key)) throwAddressableError<SyntaxError>(FStringView(std::format(
|
||||
"Redefinition of immutable key {} in mapping literal",
|
||||
key.toBasicString())));
|
||||
next(); // consume key
|
||||
expect(TokenType::Colon);
|
||||
next(); // consume `:`
|
||||
val[key] = parseExpression(0, TokenType::RightBrace, TokenType::Comma);
|
||||
if (isThis(TokenType::Comma))
|
||||
{
|
||||
next(); // consume `,`
|
||||
}
|
||||
}
|
||||
expect(TokenType::RightBrace);
|
||||
next(); // consume `}`
|
||||
return makeAst<Ast::MapExprAst>(val);
|
||||
}
|
||||
|
||||
Ast::InitExpr Parser::__parseInitExpr(FString structName)
|
||||
{
|
||||
// entry: current is `{`
|
||||
next(); // consume `{`
|
||||
std::vector<std::pair<FString, Ast::Expression>> args;
|
||||
/*
|
||||
3 ways of calling constructor
|
||||
.1 Person {"Fig", 1, "IDK"};
|
||||
.2 Person {name: "Fig", age: 1, sex: "IDK"}; // can be unordered
|
||||
.3 Person {name, age, sex};
|
||||
*/
|
||||
uint8_t mode; // 0=undetermined, 1=positional, 2=named, 3=shorthand
|
||||
|
||||
while (!isThis(TokenType::RightBrace))
|
||||
{
|
||||
if (mode == 0)
|
||||
{
|
||||
if (isThis(TokenType::Identifier) && isNext(TokenType::Colon))
|
||||
{
|
||||
mode = 2;
|
||||
}
|
||||
else if (isThis(TokenType::Identifier) && (isNext(TokenType::Comma) || isNext(TokenType::RightBrace)))
|
||||
{
|
||||
mode = 3;
|
||||
}
|
||||
else
|
||||
{
|
||||
mode = 1;
|
||||
}
|
||||
}
|
||||
|
||||
if (mode == 1)
|
||||
{
|
||||
// 1 Person {"Fig", 1, "IDK"};
|
||||
Ast::Expression expr = parseExpression(0, TokenType::Comma, TokenType::RightBrace);
|
||||
args.push_back({FString(), std::move(expr)});
|
||||
}
|
||||
else if (mode == 2)
|
||||
{
|
||||
// 2 Person {name: "Fig", age: 1, sex: "IDK"};
|
||||
expect(TokenType::Identifier);
|
||||
FString fieldName = currentToken().getValue();
|
||||
next(); // consume identifier
|
||||
expect(TokenType::Colon);
|
||||
next(); // consume colon
|
||||
Ast::Expression expr = parseExpression(0, TokenType::Comma, TokenType::RightBrace);
|
||||
args.push_back({fieldName, std::move(expr)});
|
||||
}
|
||||
else if (mode == 3)
|
||||
{
|
||||
// 3 Person {name, age, sex};
|
||||
expect(TokenType::Identifier);
|
||||
FString fieldName = currentToken().getValue();
|
||||
Ast::Expression expr = makeAst<Ast::VarExprAst>(fieldName);
|
||||
args.push_back({fieldName, std::move(expr)});
|
||||
next(); // consume identifier
|
||||
}
|
||||
|
||||
if (isThis(TokenType::Comma))
|
||||
{
|
||||
next(); // consume comma
|
||||
}
|
||||
else if (!isThis(TokenType::RightBrace))
|
||||
{
|
||||
throwAddressableError<SyntaxError>(FStringView(
|
||||
std::format("Expect `,` or `}}` in struct initialization expression, got {}",
|
||||
currentToken().toString().toBasicString())
|
||||
));
|
||||
}
|
||||
}
|
||||
expect(TokenType::RightBrace);
|
||||
next(); // consume `}`
|
||||
return makeAst<Ast::InitExprAst>(structName, args,
|
||||
(mode == 1 ? Ast::InitExprAst::InitMode::Positional :
|
||||
(mode == 2 ? Ast::InitExprAst::InitMode::Named : Ast::InitExprAst::InitMode::Shorthand)));
|
||||
}
|
||||
Ast::Expression Parser::__parseTupleOrParenExpr()
|
||||
{
|
||||
next();
|
||||
|
||||
if (currentToken().getType() == TokenType::RightParen)
|
||||
{
|
||||
next(); // consume ')'
|
||||
return makeAst<Ast::TupleExprAst>();
|
||||
}
|
||||
|
||||
Ast::Expression firstExpr = parseExpression(0);
|
||||
|
||||
if (currentToken().getType() == TokenType::Comma)
|
||||
{
|
||||
std::vector<Ast::Expression> elements;
|
||||
elements.push_back(firstExpr);
|
||||
|
||||
while (currentToken().getType() == TokenType::Comma)
|
||||
{
|
||||
next(); // consume ','
|
||||
|
||||
if (currentToken().getType() == TokenType::RightParen)
|
||||
break;
|
||||
|
||||
elements.push_back(parseExpression(0));
|
||||
}
|
||||
|
||||
expect(TokenType::RightParen);
|
||||
next(); // consume ')'
|
||||
|
||||
return makeAst<Ast::TupleExprAst>(std::move(elements));
|
||||
}
|
||||
else if (currentToken().getType() == TokenType::RightParen)
|
||||
{
|
||||
next(); // consume ')'
|
||||
return firstExpr;
|
||||
}
|
||||
else
|
||||
{
|
||||
throwAddressableError<SyntaxError>(FStringView(u8"Expect ')' or ',' after expression in parentheses"));
|
||||
}
|
||||
return nullptr; // to suppress compiler warning
|
||||
}
|
||||
|
||||
Ast::FunctionLiteralExpr Parser::__parseFunctionLiteralExpr()
|
||||
{
|
||||
// entry: current is Token::LeftParen and last is Token::Function
|
||||
/*
|
||||
Function literal:
|
||||
func (params){...}
|
||||
or
|
||||
func (params) => <expression>
|
||||
*/
|
||||
Ast::FunctionParameters params = __parseFunctionParameters();
|
||||
if (isThis(TokenType::DoubleArrow)) // =>
|
||||
{
|
||||
next();
|
||||
Ast::Expression bodyExpr = parseExpression(0);
|
||||
return makeAst<Ast::FunctionLiteralExprAst>(params, bodyExpr);
|
||||
}
|
||||
expect(TokenType::LeftBrace); // `{`
|
||||
return makeAst<Ast::FunctionLiteralExprAst>(params, __parseBlockStatement());
|
||||
}
|
||||
|
||||
Ast::Expression Parser::parseExpression(Precedence bp, TokenType stop, TokenType stop2)
|
||||
{
|
||||
Ast::Expression lhs;
|
||||
Ast::Operator op;
|
||||
|
||||
Token tok = currentToken();
|
||||
if (tok == EOFTok)
|
||||
throwAddressableError<SyntaxError>(FStringView(u8"Unexpected end of expression"));
|
||||
if (tok.getType() == stop || tok.getType() == stop2)
|
||||
{
|
||||
if (lhs == nullptr) throwAddressableError<SyntaxError>(FStringView(u8"Expected expression"));
|
||||
return lhs;
|
||||
}
|
||||
if (tok.getType() == TokenType::LeftBracket)
|
||||
{
|
||||
lhs = __parseListExpr(); // auto consume
|
||||
}
|
||||
else if (tok.getType() == TokenType::LeftParen)
|
||||
{
|
||||
lhs = __parseTupleOrParenExpr(); // auto consume
|
||||
}
|
||||
else if (tok.getType() == TokenType::LeftBrace)
|
||||
{
|
||||
lhs = __parseMapExpr(); // auto consume
|
||||
}
|
||||
else if (tok.getType() == TokenType::Function)
|
||||
{
|
||||
next(); // consume `function`
|
||||
if (currentToken().getType() == TokenType::Identifier)
|
||||
{
|
||||
// err
|
||||
throwAddressableError<SyntaxError>(FStringView(u8"Function literal should not have a name"));
|
||||
}
|
||||
expect(TokenType::LeftParen);
|
||||
lhs = __parseFunctionLiteralExpr();
|
||||
}
|
||||
else if (tok.isLiteral())
|
||||
{
|
||||
lhs = __parseValueExpr();
|
||||
next();
|
||||
}
|
||||
else if (tok.isIdentifier())
|
||||
{
|
||||
FString id = tok.getValue();
|
||||
next();
|
||||
if (currentToken().getType() == TokenType::LeftBrace)
|
||||
{
|
||||
lhs = __parseInitExpr(id); // a_struct{init...}
|
||||
}
|
||||
else
|
||||
{
|
||||
lhs = __parseVarExpr(id);
|
||||
}
|
||||
}
|
||||
else if (isTokenOp(tok) && isOpUnary((op = Ast::TokenToOp.at(tok.getType()))))
|
||||
{
|
||||
// prefix
|
||||
next();
|
||||
lhs = __parsePrefix(op, getRightBindingPower(op));
|
||||
}
|
||||
else
|
||||
{
|
||||
throwAddressableError<SyntaxError>(FStringView(u8"Unexpected token in expression"));
|
||||
}
|
||||
|
||||
// infix / (postfix) ?
|
||||
while (true)
|
||||
{
|
||||
tok = currentToken();
|
||||
if (tok.getType() == TokenType::Semicolon || tok == EOFTok) break;
|
||||
|
||||
/* Postfix */
|
||||
|
||||
if (tok.getType() == TokenType::LeftParen)
|
||||
{
|
||||
lhs = __parseCall(lhs);
|
||||
continue;
|
||||
}
|
||||
|
||||
// member access: a.b
|
||||
if (tok.getType() == TokenType::Dot)
|
||||
{
|
||||
next(); // consume '.'
|
||||
Token idTok = currentToken();
|
||||
if (!idTok.isIdentifier())
|
||||
throwAddressableError<SyntaxError>(FStringView(u8"Expected identifier after '.'"));
|
||||
|
||||
FString member = idTok.getValue();
|
||||
next(); // consume identifier
|
||||
|
||||
lhs = makeAst<Ast::MemberExprAst>(lhs, member);
|
||||
continue;
|
||||
}
|
||||
// index: x[expr]
|
||||
if (tok.getType() == TokenType::LeftBracket)
|
||||
{
|
||||
next(); // consume '['
|
||||
auto indexExpr = parseExpression(0, TokenType::RightBracket);
|
||||
expect(TokenType::RightBracket);
|
||||
next(); // consume ']'
|
||||
|
||||
lhs = makeAst<Ast::IndexExprAst>(lhs, indexExpr);
|
||||
continue;
|
||||
}
|
||||
|
||||
// ternary
|
||||
if (tok.getType() == TokenType::Question)
|
||||
{
|
||||
next(); // consume ?
|
||||
Ast::Expression trueExpr = parseExpression(0, TokenType::Colon);
|
||||
expect(TokenType::Colon);
|
||||
next(); // consume :
|
||||
Ast::Expression falseExpr = parseExpression(0, TokenType::Semicolon, stop2);
|
||||
lhs = makeAst<Ast::TernaryExprAst>(lhs, trueExpr, falseExpr);
|
||||
continue;
|
||||
}
|
||||
|
||||
if (!isTokenOp(tok)) break;
|
||||
|
||||
op = Ast::TokenToOp.at(tok.getType());
|
||||
Precedence lbp = getLeftBindingPower(op);
|
||||
if (bp >= lbp) break;
|
||||
|
||||
next(); // consume op
|
||||
lhs = __parseInfix(lhs, op, getRightBindingPower(op));
|
||||
}
|
||||
|
||||
return lhs;
|
||||
}
|
||||
|
||||
std::vector<Ast::AstBase> Parser::parseAll()
|
||||
{
|
||||
output.clear();
|
||||
Token tok = currentToken();
|
||||
if (tok == EOFTok)
|
||||
{
|
||||
return output;
|
||||
}
|
||||
|
||||
// TODO: Package/Module Import Support
|
||||
while (!isEOF())
|
||||
{
|
||||
pushNode(__parseStatement());
|
||||
}
|
||||
return output;
|
||||
}
|
||||
|
||||
} // namespace Fig
|
||||
Reference in New Issue
Block a user