93 lines
3.3 KiB
C++
93 lines
3.3 KiB
C++
#include "parsing.h"
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namespace parsing {
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namespace {
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Result<std::unique_ptr<AST::Type>, std::string> parse_type(token::TokenStream& stream) {
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token::TokenStream inner{ stream };
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try {
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auto token = inner.expect(token::Type::Ident);
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stream.m_position = inner.m_position;
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auto ty = new AST::FundamentalType{ AST::FundamentalTypeKind::Int };
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return new std::unique_ptr<AST::Type>{ ty };
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}
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catch (std::runtime_error error) {
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return new std::string{ error.what() };
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}
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}
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Result<std::unique_ptr<AST::Expression>, std::string> parse_expression(token::TokenStream& stream) {
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token::TokenStream inner{ stream };
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try {
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auto token = inner.next();
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if (token.type == token::Type::LiteralInt) {
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stream.m_position = inner.m_position;
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auto expr = new AST::IntLiteralExpression{ 5 };
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return new std::unique_ptr<AST::Expression>{ expr };
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}
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else {
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throw std::runtime_error("Expected expression");
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}
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}
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catch (std::runtime_error error) {
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return new std::string{ error.what() };
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}
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}
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Result<std::unique_ptr<AST::Statement>, std::string> parse_statement(token::TokenStream& stream) {
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token::TokenStream inner{ stream };
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try {
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if (inner.peek().type == token::Type::ReturnKeyword) {
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inner.next();
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auto expression = parse_expression(inner).unwrap();
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inner.expect(token::Type::Symbol, ";");
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stream.m_position = inner.m_position;
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auto ret = new AST::ReturnStatement{ std::move(expression) };
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return new std::unique_ptr<AST::Statement>{ ret };
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}
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else {
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throw std::runtime_error("Expected return-keyword");
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}
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}
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catch (std::runtime_error error) {
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return new std::string{ error.what() };
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}
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}
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}
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Result<std::unique_ptr<AST::TopLevelStatement>, std::string> parse_top_level_statement(token::TokenStream& stream) {
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token::TokenStream inner{ stream };
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try {
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auto type = parse_type(inner).unwrap();
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auto name_token = inner.expect(token::Type::Ident);
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inner.expect(token::Type::Symbol, "(");
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inner.expect(token::Type::Symbol, ")");
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inner.expect(token::Type::Symbol, "{");
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std::vector<std::unique_ptr<AST::Statement>> statements{};
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auto statement = parse_statement(inner);
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while (statement.ok()) {
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statements.push_back(statement.unwrap());
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statement = parse_statement(inner);
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}
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inner.expect(token::Type::Symbol, "}");
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stream.m_position = inner.m_position;
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auto fun = new AST::Function{ std::move(type), {}, "main", std::move(statements) };
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return new std::unique_ptr<AST::TopLevelStatement>{ fun };
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}
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catch (std::runtime_error error) {
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return new std::string(error.what());
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}
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}
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} |