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Implement comparison operators

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This commit is contained in:
Eugen Wissner
2024-04-02 09:07:13 +02:00
parent 33a951687b
commit 0cad759415
9 changed files with 205 additions and 42 deletions
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92
source/lexer.cpp
View File

@ -204,7 +204,8 @@ namespace elna::source
{
return of() == type::identifier
|| of() == type::term_operator
|| of() == type::factor_operator;
|| of() == type::factor_operator
|| of() == type::comparison_operator;
}
bool token::is_numeric() const noexcept
@ -218,51 +219,53 @@ namespace elna::source
switch (this->m_type)
{
case type::number:
return "«number»";
return "«number»";
case type::boolean:
return "«boolean»";
return "«boolean»";
case type::term_operator:
return "«term_operator»";
return "«term_operator»";
case type::let:
return "«const»";
return "«const»";
case type::identifier:
return "«identifier»";
return "«identifier»";
case type::equals:
return "«=»";
return "«=»";
case type::var:
return "«var»";
return "«var»";
case type::semicolon:
return "«;»";
return "«;»";
case type::left_paren:
return "«(»";
return "«(»";
case type::right_paren:
return "«)»";
return "«)»";
case type::dot:
return "«)»";
return "«)»";
case type::comma:
return "«,»";
return "«,»";
case type::factor_operator:
return "«*»";
return "«*»";
case type::eof:
return "«EOF»";
return "«EOF»";
case type::begin:
return "«begin»";
return "«begin»";
case type::end:
return "«end»";
return "«end»";
case type::assignment:
return "«:=»";
return "«:=»";
case type::colon:
return "«:»";
return "«:»";
case type::when:
return "«if»";
return "«if»";
case type::then:
return "«then»";
case type::_while:
return "«while»";
return "«then»";
case type::loop:
return "«while»";
case type::_do:
return "«do»";
return "«do»";
case type::procedure:
return "«proc»";
return "«proc»";
case type::comparison_operator:
return "«comparison_operator»";
};
assert(false);
}
@ -446,7 +449,7 @@ namespace elna::source
}
else if (word == "while")
{
tokens.emplace_back(token::type::_while, iterator.position());
tokens.emplace_back(token::type::loop, iterator.position());
}
else if (word == "do")
{
@ -477,12 +480,49 @@ namespace elna::source
tokens.emplace_back(token::type::term_operator, _operator.c_str(), iterator.position());
}
else if (*iterator == '/' && iterator + 1 != text_end && *(iterator + 1) == '=')
{
tokens.emplace_back(token::type::comparison_operator, "n", iterator.position());
++iterator;
}
else if (*iterator == '*' || *iterator == '/')
{
std::string _operator{ *iterator };
tokens.emplace_back(token::type::factor_operator, _operator.c_str(), iterator.position());
}
else if (*iterator == '<')
{
std::string _operator;
auto operator_position = iterator.position();
if (iterator + 1 == text_end || *(iterator + 1) != '=')
{
_operator.push_back(*iterator);
}
else
{
++iterator;
_operator.push_back('l');
}
tokens.emplace_back(token::type::comparison_operator, _operator.c_str(), operator_position);
}
else if (*iterator == '>')
{
std::string _operator;
auto operator_position = iterator.position();
if (iterator + 1 == text_end || *(iterator + 1) != '=')
{
_operator.push_back(*iterator);
}
else
{
++iterator;
_operator.push_back('g');
}
tokens.emplace_back(token::type::comparison_operator, _operator.c_str(), operator_position);
}
else if (*iterator == ':' && iterator + 1 != text_end && *(iterator + 1) == '=')
{
tokens.emplace_back(token::type::assignment, iterator.position());

64
source/parser.cpp
View File

@ -262,6 +262,24 @@ namespace elna::source
case '/':
this->m_operator = binary_operator::division;
break;
case '=':
this->m_operator = binary_operator::equals;
break;
case 'n':
this->m_operator = binary_operator::not_equals;
break;
case '<':
this->m_operator = binary_operator::less;
break;
case 'l':
this->m_operator = binary_operator::less_equal;
break;
case '>':
this->m_operator = binary_operator::greater;
break;
case 'g':
this->m_operator = binary_operator::greater_equal;
break;
default:
throw std::logic_error("Invalid binary operator");
}
@ -442,7 +460,7 @@ namespace elna::source
{
++iterator;
auto expression = parse_expression();
auto expression = parse_condition();
++iterator;
@ -489,6 +507,38 @@ namespace elna::source
return term;
}
std::unique_ptr<expression> parser::parse_condition()
{
std::unique_ptr<expression> lhs;
if ((lhs = parse_expression()) == nullptr)
{
return lhs;
}
unsigned char _operator{ 0 };
if (iterator.current().of() == source::token::type::equals)
{
_operator = '=';
}
else if (iterator.current().of() == source::token::type::comparison_operator)
{
_operator = iterator->identifier()[0];
}
else
{
return lhs;
}
++iterator;
auto rhs = parse_expression();
if (rhs == nullptr)
{
return nullptr;
}
return std::make_unique<binary_expression>(std::move(lhs), std::move(rhs), _operator);
}
std::unique_ptr<constant_definition> parser::parse_constant_definition()
{
auto definition_identifier = iterator.advance(token::type::identifier);
@ -595,7 +645,7 @@ namespace elna::source
{
return parse_if_statement();
}
else if (iterator.current(token::type::_while))
else if (iterator.current(token::type::loop))
{
return parse_while_statement();
}
@ -618,7 +668,7 @@ namespace elna::source
++iterator;
return call;
}
while ((argument_expression = parse_expression()) != nullptr)
while ((argument_expression = parse_condition()) != nullptr)
{
call->arguments().push_back(std::move(argument_expression));
@ -674,7 +724,7 @@ namespace elna::source
{
return nullptr;
}
auto rvalue = parse_expression();
auto rvalue = parse_condition();
if (rvalue == nullptr)
{
@ -689,7 +739,7 @@ namespace elna::source
{
return nullptr;
}
auto condition = parse_expression();
auto condition = parse_condition();
if (condition == nullptr || !iterator.skip(token::type::then))
{
@ -706,11 +756,11 @@ namespace elna::source
std::unique_ptr<while_statement> parser::parse_while_statement()
{
if (!iterator.skip(token::type::_while))
if (!iterator.skip(token::type::loop))
{
return nullptr;
}
auto condition = parse_expression();
auto condition = parse_condition();
if (condition == nullptr || !iterator.skip(token::type::_do))
{