/* * Copyright (c) 2020, Andreas Kling * * SPDX-License-Identifier: BSD-2-Clause */ #include "GMLLexer.h" #include #include namespace GUI { GMLLexer::GMLLexer(StringView const& input) : m_input(input) { } char GMLLexer::peek(size_t offset) const { if ((m_index + offset) >= m_input.length()) return 0; return m_input[m_index + offset]; } char GMLLexer::consume() { VERIFY(m_index < m_input.length()); char ch = m_input[m_index++]; if (ch == '\n') { m_position.line++; m_position.column = 0; } else { m_position.column++; } return ch; } constexpr bool is_valid_identifier_start(char ch) { return is_ascii_alpha(ch) || ch == '_'; } constexpr bool is_valid_identifier_character(char ch) { return is_ascii_alphanumeric(ch) || ch == '_'; } constexpr bool is_valid_class_character(char ch) { return is_ascii_alphanumeric(ch) || ch == '_' || ch == ':'; } Vector GMLLexer::lex() { Vector tokens; size_t token_start_index = 0; GMLPosition token_start_position; auto begin_token = [&] { token_start_index = m_index; token_start_position = m_position; }; auto commit_token = [&](auto type) { GMLToken token; token.m_view = m_input.substring_view(token_start_index, m_index - token_start_index); token.m_type = type; token.m_start = token_start_position; token.m_end = m_position; tokens.append(token); }; auto consume_class = [&] { begin_token(); consume(); commit_token(GMLToken::Type::ClassMarker); begin_token(); while (is_valid_class_character(peek())) consume(); commit_token(GMLToken::Type::ClassName); }; while (m_index < m_input.length()) { if (is_ascii_space(peek(0))) { begin_token(); while (is_ascii_space(peek())) consume(); continue; } // C++ style comments if (peek(0) && peek(0) == '/' && peek(1) == '/') { begin_token(); while (peek() && peek() != '\n') consume(); commit_token(GMLToken::Type::Comment); continue; } if (peek(0) == '{') { begin_token(); consume(); commit_token(GMLToken::Type::LeftCurly); continue; } if (peek(0) == '}') { begin_token(); consume(); commit_token(GMLToken::Type::RightCurly); continue; } if (peek(0) == '@') { consume_class(); continue; } if (is_valid_identifier_start(peek(0))) { begin_token(); consume(); while (is_valid_identifier_character(peek(0))) consume(); commit_token(GMLToken::Type::Identifier); continue; } if (peek(0) == ':') { begin_token(); consume(); commit_token(GMLToken::Type::Colon); while (is_ascii_space(peek())) consume(); if (peek(0) == '@') { consume_class(); } else { begin_token(); while (peek() && peek() != '\n') consume(); commit_token(GMLToken::Type::JsonValue); } continue; } consume(); commit_token(GMLToken::Type::Unknown); } return tokens; } }