Libraries: Move to Userland/Libraries/

1 files changed, 85 insertions, 0 deletions

diff --git a/Userland/Libraries/LibJS/Lexer.h b/Userland/Libraries/LibJS/Lexer.h
new file mode 100644
index 0000000000..3efe290aa8
--- /dev/null
+++ b/Userland/Libraries/LibJS/Lexer.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2020, Stephan Unverwerth <s.unverwerth@gmx.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#pragma once
+
+#include "Token.h"
+
+#include <AK/HashMap.h>
+#include <AK/String.h>
+#include <AK/StringView.h>
+
+namespace JS {
+
+class Lexer {
+public:
+    explicit Lexer(StringView source);
+
+    Token next();
+
+    const StringView& source() const { return m_source; };
+
+private:
+    void consume();
+    bool consume_exponent();
+    bool consume_octal_number();
+    bool consume_hexadecimal_number();
+    bool consume_binary_number();
+    bool is_eof() const;
+    bool is_line_terminator() const;
+    bool is_identifier_start() const;
+    bool is_identifier_middle() const;
+    bool is_line_comment_start(bool line_has_token_yet) const;
+    bool is_block_comment_start() const;
+    bool is_block_comment_end() const;
+    bool is_numeric_literal_start() const;
+    bool match(char, char) const;
+    bool match(char, char, char) const;
+    bool match(char, char, char, char) const;
+    bool slash_means_division() const;
+
+    StringView m_source;
+    size_t m_position { 0 };
+    Token m_current_token;
+    char m_current_char { 0 };
+    size_t m_line_number { 1 };
+    size_t m_line_column { 0 };
+
+    bool m_regex_is_in_character_class { false };
+
+    struct TemplateState {
+        bool in_expr;
+        u8 open_bracket_count;
+    };
+    Vector<TemplateState> m_template_states;
+
+    static HashMap<String, TokenType> s_keywords;
+    static HashMap<String, TokenType> s_three_char_tokens;
+    static HashMap<String, TokenType> s_two_char_tokens;
+    static HashMap<char, TokenType> s_single_char_tokens;
+};
+
+}