73 lines
2.1 KiB
C++
73 lines
2.1 KiB
C++
#pragma once
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#include "AST/NumberNode.h"
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#include "Error.h"
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#include "Lexer.h"
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#include "sapphirepch.h"
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/* Parser class for the Sapphire compiler. */
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class Parser
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{
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/* Struct to store a parsing result which can be either a parsing error or a success, in which case it contains a
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* pointer to the result. */
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template<typename T> struct ErrorOr
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{
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/* Return the stored pointer. */
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std::shared_ptr<T> get()
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{
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assert(!m_is_error);
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return m_ptr;
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}
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/* Call Error::throw_error() with the stored error's location, line text, and the error string provided to this
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* struct instance. */
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void ethrow()
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{
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assert(m_is_error);
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Error::throw_error(error_tok->loc, error_tok->line(), m_error);
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}
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/* Construct a new successful ErrorOr with a heap-allocated pointer to the result class. */
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ErrorOr(T* ptr) : m_ptr(ptr), m_is_error(false)
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{
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}
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/* Construct a new failed ErrorOr with the error details and the token where parsing failed. */
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ErrorOr(const std::string& error, const Token& error_tok)
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: m_error(error), m_is_error(true), error_tok(error_tok)
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{
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}
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/* Is this ErrorOr instance successful or failed? */
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bool is_error()
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{
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return m_is_error;
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}
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private:
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bool m_is_error;
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std::string m_error;
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std::unique_ptr<Token> error_tok;
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std::shared_ptr<T> m_ptr;
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};
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private:
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Parser(const TokenStream& tokens);
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TokenStream tokens;
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ErrorOr<ExprNode> walk_expr();
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ErrorOr<NumberNode> walk_number();
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int m_index;
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int saved_m_index;
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void save_current_position();
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void restore_current_position();
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public:
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~Parser();
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/* Construct a new Parser with the given TokenStream. */
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static std::shared_ptr<Parser> new_parser(const TokenStream& tokens);
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/* Parse the stored TokenStream and return the top-level node of the result Abstract Syntax Tree. */
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std::shared_ptr<ASTNode> parse();
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};
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