ladybird/Libraries/LibGUI/CppLexer.cpp
Andreas Kling bb8e65be41 LibGUI+HackStudio: Move syntax highlighting from HackStudio to LibGUI
This patch introduces the GUI::SyntaxHighlighter class, which can be
attached to a GUI::TextEditor to provide syntax highlighting.

The C++ syntax highlighting from HackStudio becomes a new class called
GUI::CppSyntaxHighlighter. This will make it possible to get C++ syntax
highlighting in any app that uses a GUI::TextEditor. :^)

Sidenote: It does feel a bit weird having a C++ lexer in a GUI toolkit
library, and we'll probably end up moving this out to a separate place
as this functionality grows larger.
2020-02-07 20:07:15 +01:00

374 lines
11 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* 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.
*/
#include "CppLexer.h"
#include <AK/HashTable.h>
#include <AK/String.h>
#include <ctype.h>
namespace GUI {
CppLexer::CppLexer(const StringView& input)
: m_input(input)
{
}
char CppLexer::peek(size_t offset) const
{
if ((m_index + offset) >= m_input.length())
return 0;
return m_input[m_index + offset];
}
char CppLexer::consume()
{
ASSERT(m_index < m_input.length());
char ch = m_input[m_index++];
m_previous_position = m_position;
if (ch == '\n') {
m_position.line++;
m_position.column = 0;
} else {
m_position.column++;
}
return ch;
}
static bool is_valid_first_character_of_identifier(char ch)
{
return isalpha(ch) || ch == '_' || ch == '$';
}
static bool is_valid_nonfirst_character_of_identifier(char ch)
{
return is_valid_first_character_of_identifier(ch) || isdigit(ch);
}
static bool is_keyword(const StringView& string)
{
static HashTable<String> keywords;
if (keywords.is_empty()) {
keywords.set("alignas");
keywords.set("alignof");
keywords.set("and");
keywords.set("and_eq");
keywords.set("asm");
keywords.set("bitand");
keywords.set("bitor");
keywords.set("bool");
keywords.set("break");
keywords.set("case");
keywords.set("catch");
keywords.set("class");
keywords.set("compl");
keywords.set("const");
keywords.set("const_cast");
keywords.set("constexpr");
keywords.set("continue");
keywords.set("decltype");
keywords.set("default");
keywords.set("delete");
keywords.set("do");
keywords.set("dynamic_cast");
keywords.set("else");
keywords.set("enum");
keywords.set("explicit");
keywords.set("export");
keywords.set("extern");
keywords.set("false");
keywords.set("final");
keywords.set("for");
keywords.set("friend");
keywords.set("goto");
keywords.set("if");
keywords.set("inline");
keywords.set("mutable");
keywords.set("namespace");
keywords.set("new");
keywords.set("noexcept");
keywords.set("not");
keywords.set("not_eq");
keywords.set("nullptr");
keywords.set("operator");
keywords.set("or");
keywords.set("or_eq");
keywords.set("override");
keywords.set("private");
keywords.set("protected");
keywords.set("public");
keywords.set("register");
keywords.set("reinterpret_cast");
keywords.set("return");
keywords.set("signed");
keywords.set("sizeof");
keywords.set("static");
keywords.set("static_assert");
keywords.set("static_cast");
keywords.set("struct");
keywords.set("switch");
keywords.set("template");
keywords.set("this");
keywords.set("thread_local");
keywords.set("throw");
keywords.set("true");
keywords.set("try");
keywords.set("typedef");
keywords.set("typeid");
keywords.set("typename");
keywords.set("union");
keywords.set("using");
keywords.set("virtual");
keywords.set("volatile");
keywords.set("while");
keywords.set("xor");
keywords.set("xor_eq");
}
return keywords.contains(string);
}
static bool is_known_type(const StringView& string)
{
static HashTable<String> types;
if (types.is_empty()) {
types.set("ByteBuffer");
types.set("CircularDeque");
types.set("CircularQueue");
types.set("Deque");
types.set("DoublyLinkedList");
types.set("FileSystemPath");
types.set("FixedArray");
types.set("Function");
types.set("HashMap");
types.set("HashTable");
types.set("IPv4Address");
types.set("InlineLinkedList");
types.set("IntrusiveList");
types.set("JsonArray");
types.set("JsonObject");
types.set("JsonValue");
types.set("MappedFile");
types.set("NetworkOrdered");
types.set("NonnullOwnPtr");
types.set("NonnullOwnPtrVector");
types.set("NonnullRefPtr");
types.set("NonnullRefPtrVector");
types.set("Optional");
types.set("OwnPtr");
types.set("RefPtr");
types.set("Result");
types.set("ScopeGuard");
types.set("SinglyLinkedList");
types.set("String");
types.set("StringBuilder");
types.set("StringImpl");
types.set("StringView");
types.set("Utf8View");
types.set("Vector");
types.set("WeakPtr");
types.set("auto");
types.set("char");
types.set("char16_t");
types.set("char32_t");
types.set("char8_t");
types.set("double");
types.set("float");
types.set("i16");
types.set("i32");
types.set("i64");
types.set("i8");
types.set("int");
types.set("int");
types.set("long");
types.set("short");
types.set("signed");
types.set("u16");
types.set("u32");
types.set("u64");
types.set("u8");
types.set("unsigned");
types.set("void");
types.set("wchar_t");
}
return types.contains(string);
}
Vector<CppToken> CppLexer::lex()
{
Vector<CppToken> tokens;
size_t token_start_index = 0;
CppPosition token_start_position;
auto emit_token = [&](auto type) {
CppToken token;
token.m_type = type;
token.m_start = m_position;
token.m_end = m_position;
tokens.append(token);
consume();
};
auto begin_token = [&] {
token_start_index = m_index;
token_start_position = m_position;
};
auto commit_token = [&](auto type) {
CppToken token;
token.m_type = type;
token.m_start = token_start_position;
token.m_end = m_previous_position;
tokens.append(token);
};
while (m_index < m_input.length()) {
auto ch = peek();
if (isspace(ch)) {
begin_token();
while (isspace(peek()))
consume();
commit_token(CppToken::Type::Whitespace);
continue;
}
if (ch == '(') {
emit_token(CppToken::Type::LeftParen);
continue;
}
if (ch == ')') {
emit_token(CppToken::Type::RightParen);
continue;
}
if (ch == '{') {
emit_token(CppToken::Type::LeftCurly);
continue;
}
if (ch == '}') {
emit_token(CppToken::Type::RightCurly);
continue;
}
if (ch == '[') {
emit_token(CppToken::Type::LeftBracket);
continue;
}
if (ch == ']') {
emit_token(CppToken::Type::RightBracket);
continue;
}
if (ch == ',') {
emit_token(CppToken::Type::Comma);
continue;
}
if (ch == '*') {
emit_token(CppToken::Type::Asterisk);
continue;
}
if (ch == ';') {
emit_token(CppToken::Type::Semicolon);
continue;
}
if (ch == '#') {
begin_token();
while (peek() && peek() != '\n')
consume();
commit_token(CppToken::Type::PreprocessorStatement);
continue;
}
if (ch == '/' && peek(1) == '/') {
begin_token();
while (peek() && peek() != '\n')
consume();
commit_token(CppToken::Type::Comment);
continue;
}
if (ch == '/' && peek(1) == '*') {
begin_token();
consume();
consume();
bool comment_block_ends = false;
while (peek()) {
if (peek() == '*' && peek(1) == '/') {
comment_block_ends = true;
break;
}
consume();
}
if (comment_block_ends) {
consume();
consume();
}
commit_token(CppToken::Type::Comment);
continue;
}
if (ch == '"') {
begin_token();
consume();
while (peek()) {
if (consume() == '"')
break;
}
commit_token(CppToken::Type::DoubleQuotedString);
continue;
}
if (ch == '\'') {
begin_token();
consume();
while (peek()) {
if (consume() == '\'')
break;
}
commit_token(CppToken::Type::SingleQuotedString);
continue;
}
if (isdigit(ch)) {
begin_token();
while (peek() && isdigit(peek())) {
consume();
}
commit_token(CppToken::Type::Number);
continue;
}
if (is_valid_first_character_of_identifier(ch)) {
begin_token();
while (peek() && is_valid_nonfirst_character_of_identifier(peek()))
consume();
auto token_view = StringView(m_input.characters_without_null_termination() + token_start_index, m_index - token_start_index);
if (is_keyword(token_view))
commit_token(CppToken::Type::Keyword);
else if (is_known_type(token_view))
commit_token(CppToken::Type::KnownType);
else
commit_token(CppToken::Type::Identifier);
continue;
}
dbg() << "Unimplemented token character: " << ch;
emit_token(CppToken::Type::Unknown);
}
return tokens;
}
}