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ImHex/source/lang/lexer.cpp
2020-11-20 21:59:27 +01:00

199 lines
8.6 KiB
C++

#include "lang/lexer.hpp"
#include <vector>
#include <functional>
namespace hex::lang {
Lexer::Lexer() { }
std::string matchTillInvalid(const char* characters, std::function<bool(char)> predicate) {
std::string ret;
while (*characters != 0x00) {
ret += *characters;
characters++;
if (!predicate(*characters))
break;
}
return ret;
}
std::optional<u64> parseInt(std::string_view string) {
u64 integer = 0;
u8 base;
std::string_view numberData;
if (string.starts_with("0x")) {
numberData = string.substr(2);
base = 16;
if (numberData.find_first_not_of("0123456789ABCDEFabcdef") != std::string_view::npos)
return { };
} else if (string.starts_with("0b")) {
numberData = string.substr(2);
base = 2;
if (numberData.find_first_not_of("01") != std::string_view::npos)
return { };
} else if (isdigit(string[0])) {
numberData = string;
base = 10;
if (numberData.find_first_not_of("0123456789") != std::string_view::npos)
return { };
} else return { };
if (numberData.length() == 0)
return { };
for (const char& c : numberData) {
integer *= base;
if (isdigit(c))
integer += (c - '0');
else if (c >= 'A' && c <= 'F')
integer += 10 + (c - 'A');
else if (c >= 'a' && c <= 'f')
integer += 10 + (c - 'a');
else return { };
}
return integer;
}
std::pair<Result, std::vector<Token>> Lexer::lex(const std::string& code) {
std::vector<Token> tokens;
u32 offset = 0;
while (offset < code.length()) {
// Handle comments
if (code[offset] == '/') {
offset++;
if (offset < code.length() && code[offset] == '/') {
offset++;
while (offset < code.length()) {
if (code[offset] == '\n' || code[offset] == '\r')
break;
offset++;
}
} else if (offset < code.length() && code[offset] == '*') {
offset++;
while (offset < (code.length() - 1)) {
if (code[offset] == '*' && code[offset + 1] == '/')
break;
offset++;
}
offset += 2;
} else offset--;
}
const char& c = code[offset];
if (c == 0x00)
break;
if (std::isblank(c) || std::isspace(c)) {
offset += 1;
} else if (c == ';') {
tokens.push_back({ .type = Token::Type::EndOfExpression });
offset += 1;
} else if (c == '{') {
tokens.push_back({ .type = Token::Type::ScopeOpen });
offset += 1;
} else if (c == '}') {
tokens.push_back({ .type = Token::Type::ScopeClose });
offset += 1;
} else if (c == '[') {
tokens.push_back({ .type = Token::Type::ArrayOpen });
offset += 1;
} else if (c == ']') {
tokens.push_back({.type = Token::Type::ArrayClose});
offset += 1;
} else if (c == ',') {
tokens.push_back({ .type = Token::Type::Separator });
offset += 1;
} else if (c == '@') {
tokens.push_back({ .type = Token::Type::Operator, .operatorToken = { .op = Token::OperatorToken::Operator::AtDeclaration } });
offset += 1;
} else if (c == '=') {
tokens.push_back({ .type = Token::Type::Operator, .operatorToken = { .op = Token::OperatorToken::Operator::Assignment } });
offset += 1;
} else if (c == ':') {
tokens.push_back({ .type = Token::Type::Operator, .operatorToken = { .op = Token::OperatorToken::Operator::Inherit } });
offset += 1;
} else if (std::isalpha(c)) {
std::string identifier = matchTillInvalid(&code[offset], [](char c) -> bool { return std::isalnum(c) || c == '_'; });
// Check for reserved keywords
if (identifier == "struct")
tokens.push_back({ .type = Token::Type::Keyword, .keywordToken = { .keyword = Token::KeywordToken::Keyword::Struct } });
else if (identifier == "union")
tokens.push_back({ .type = Token::Type::Keyword, .keywordToken = { .keyword = Token::KeywordToken::Keyword::Union } });
else if (identifier == "using")
tokens.push_back({ .type = Token::Type::Keyword, .keywordToken = { .keyword = Token::KeywordToken::Keyword::Using } });
else if (identifier == "enum")
tokens.push_back({ .type = Token::Type::Keyword, .keywordToken = { .keyword = Token::KeywordToken::Keyword::Enum } });
else if (identifier == "bitfield")
tokens.push_back({ .type = Token::Type::Keyword, .keywordToken = { .keyword = Token::KeywordToken::Keyword::Bitfield } });
// Check for built-in types
else if (identifier == "u8")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Unsigned8Bit } });
else if (identifier == "s8")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Signed8Bit } });
else if (identifier == "u16")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Unsigned16Bit } });
else if (identifier == "s16")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Signed16Bit } });
else if (identifier == "u32")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Unsigned32Bit } });
else if (identifier == "s32")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Signed32Bit } });
else if (identifier == "u64")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Unsigned64Bit } });
else if (identifier == "s64")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Signed64Bit } });
else if (identifier == "u128")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Unsigned128Bit } });
else if (identifier == "s128")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Signed128Bit } });
else if (identifier == "float")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Float } });
else if (identifier == "double")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Double } });
else if (identifier == "padding")
tokens.push_back({ .type = Token::Type::Type, .typeToken = { .type = Token::TypeToken::Type::Padding } });
// If it's not a keyword and a builtin type, it has to be an identifier
else
tokens.push_back({.type = Token::Type::Identifier, .identifierToken = { .identifier = identifier } });
offset += identifier.length();
} else if (std::isdigit(c)) {
char *end = nullptr;
std::strtoull(&code[offset], &end, 0);
auto integer = parseInt(std::string_view(&code[offset], end));
if (!integer.has_value())
return { ResultLexicalError, {}};
tokens.push_back({ .type = Token::Type::Integer, .integerToken = { .integer = integer.value() } });
offset += (end - &code[offset]);
} else return { ResultLexicalError, {}};
}
tokens.push_back({ .type = Token::Type::EndOfProgram });
return { ResultSuccess, tokens };
}
}