68 lines
1.4 KiB
C++
68 lines
1.4 KiB
C++
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#include <musique.hh>
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Result<Ast> Parser::parse(std::string_view source, std::string_view filename)
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{
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Lexer lexer{source};
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lexer.location.filename = filename;
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Parser parser;
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for (;;) if (auto maybe_token = lexer.next_token(); maybe_token.has_value()) {
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parser.tokens.emplace_back(*std::move(maybe_token));
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} else if (maybe_token.error().type == errors::End_Of_File) {
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break;
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} else {
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return std::move(maybe_token).error();
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}
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auto const result = parser.parse_expression();
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if (parser.token_id < parser.tokens.size()) {
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errors::all_tokens_were_not_parsed(std::span(parser.tokens).subspan(parser.token_id));
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}
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return result;
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}
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Result<Ast> Parser::parse_expression()
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{
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return parse_binary_operator();
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}
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Result<Ast> Parser::parse_binary_operator()
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{
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return parse_literal();
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}
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Result<Ast> Parser::parse_literal()
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{
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Try(ensure(Token::Type::Numeric));
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return Ast::literal(consume());
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}
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Token Parser::consume()
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{
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return std::move(tokens[token_id++]);
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}
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bool Parser::expect(Token::Type type) const
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{
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return token_id < tokens.size() && tokens[token_id].type == type;
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}
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Result<Unit> Parser::ensure(Token::Type type) const
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{
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return token_id >= tokens.size()
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? errors::unexpected_end_of_source(tokens.back().location)
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: tokens[token_id].type != type
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? errors::unexpected_token(type, tokens[token_id])
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: Result<Unit>{};
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}
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Ast Ast::literal(Token token)
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{
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Ast ast;
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ast.type = Ast::Type::Literal;
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ast.token = std::move(token);
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return ast;
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}
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