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/*
* Copyright (c) 2021, Jan de Visser <jan@de-visser.net>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibRegex/Regex.h>
#include <LibSQL/AST/AST.h>
#include <LibSQL/Database.h>
namespace SQL::AST {
static const String s_posix_basic_metacharacters = ".^$*[]+\\";
ResultOr<Value> Expression::evaluate(ExecutionContext&) const
{
return Value::null();
}
ResultOr<Value> NumericLiteral::evaluate(ExecutionContext&) const
{
Value ret(SQLType::Float);
ret = value();
return ret;
}
ResultOr<Value> StringLiteral::evaluate(ExecutionContext&) const
{
Value ret(SQLType::Text);
ret = value();
return ret;
}
ResultOr<Value> NullLiteral::evaluate(ExecutionContext&) const
{
return Value::null();
}
ResultOr<Value> NestedExpression::evaluate(ExecutionContext& context) const
{
return expression()->evaluate(context);
}
ResultOr<Value> ChainedExpression::evaluate(ExecutionContext& context) const
{
Value ret(SQLType::Tuple);
Vector<Value> values;
for (auto& expression : expressions())
values.append(TRY(expression.evaluate(context)));
ret = values;
return ret;
}
ResultOr<Value> BinaryOperatorExpression::evaluate(ExecutionContext& context) const
{
Value lhs_value = TRY(lhs()->evaluate(context));
Value rhs_value = TRY(rhs()->evaluate(context));
switch (type()) {
case BinaryOperator::Concatenate: {
if (lhs_value.type() != SQLType::Text)
return Result { SQLCommand::Unknown, SQLErrorCode::BooleanOperatorTypeMismatch, BinaryOperator_name(type()) };
AK::StringBuilder builder;
builder.append(lhs_value.to_string());
builder.append(rhs_value.to_string());
return Value(builder.to_string());
}
case BinaryOperator::Multiplication:
return lhs_value.multiply(rhs_value);
case BinaryOperator::Division:
return lhs_value.divide(rhs_value);
case BinaryOperator::Modulo:
return lhs_value.modulo(rhs_value);
case BinaryOperator::Plus:
return lhs_value.add(rhs_value);
case BinaryOperator::Minus:
return lhs_value.subtract(rhs_value);
case BinaryOperator::ShiftLeft:
return lhs_value.shift_left(rhs_value);
case BinaryOperator::ShiftRight:
return lhs_value.shift_right(rhs_value);
case BinaryOperator::BitwiseAnd:
return lhs_value.bitwise_and(rhs_value);
case BinaryOperator::BitwiseOr:
return lhs_value.bitwise_or(rhs_value);
case BinaryOperator::LessThan:
return Value(lhs_value.compare(rhs_value) < 0);
case BinaryOperator::LessThanEquals:
return Value(lhs_value.compare(rhs_value) <= 0);
case BinaryOperator::GreaterThan:
return Value(lhs_value.compare(rhs_value) > 0);
case BinaryOperator::GreaterThanEquals:
return Value(lhs_value.compare(rhs_value) >= 0);
case BinaryOperator::Equals:
return Value(lhs_value.compare(rhs_value) == 0);
case BinaryOperator::NotEquals:
return Value(lhs_value.compare(rhs_value) != 0);
case BinaryOperator::And: {
auto lhs_bool_maybe = lhs_value.to_bool();
auto rhs_bool_maybe = rhs_value.to_bool();
if (!lhs_bool_maybe.has_value() || !rhs_bool_maybe.has_value())
return Result { SQLCommand::Unknown, SQLErrorCode::BooleanOperatorTypeMismatch, BinaryOperator_name(type()) };
return Value(lhs_bool_maybe.release_value() && rhs_bool_maybe.release_value());
}
case BinaryOperator::Or: {
auto lhs_bool_maybe = lhs_value.to_bool();
auto rhs_bool_maybe = rhs_value.to_bool();
if (!lhs_bool_maybe.has_value() || !rhs_bool_maybe.has_value())
return Result { SQLCommand::Unknown, SQLErrorCode::BooleanOperatorTypeMismatch, BinaryOperator_name(type()) };
return Value(lhs_bool_maybe.release_value() || rhs_bool_maybe.release_value());
}
default:
VERIFY_NOT_REACHED();
}
}
ResultOr<Value> UnaryOperatorExpression::evaluate(ExecutionContext& context) const
{
Value expression_value = TRY(NestedExpression::evaluate(context));
switch (type()) {
case UnaryOperator::Plus:
if (expression_value.type() == SQLType::Integer || expression_value.type() == SQLType::Float)
return expression_value;
return Result { SQLCommand::Unknown, SQLErrorCode::NumericOperatorTypeMismatch, UnaryOperator_name(type()) };
case UnaryOperator::Minus:
if (expression_value.type() == SQLType::Integer) {
expression_value = -int(expression_value);
return expression_value;
}
if (expression_value.type() == SQLType::Float) {
expression_value = -double(expression_value);
return expression_value;
}
return Result { SQLCommand::Unknown, SQLErrorCode::NumericOperatorTypeMismatch, UnaryOperator_name(type()) };
case UnaryOperator::Not:
if (expression_value.type() == SQLType::Boolean) {
expression_value = !bool(expression_value);
return expression_value;
}
return Result { SQLCommand::Unknown, SQLErrorCode::BooleanOperatorTypeMismatch, UnaryOperator_name(type()) };
case UnaryOperator::BitwiseNot:
if (expression_value.type() == SQLType::Integer) {
expression_value = ~u32(expression_value);
return expression_value;
}
return Result { SQLCommand::Unknown, SQLErrorCode::IntegerOperatorTypeMismatch, UnaryOperator_name(type()) };
default:
VERIFY_NOT_REACHED();
}
}
ResultOr<Value> ColumnNameExpression::evaluate(ExecutionContext& context) const
{
if (!context.current_row)
return Result { SQLCommand::Unknown, SQLErrorCode::SyntaxError, column_name() };
auto& descriptor = *context.current_row->descriptor();
VERIFY(context.current_row->size() == descriptor.size());
Optional<size_t> index_in_row;
for (auto ix = 0u; ix < context.current_row->size(); ix++) {
auto& column_descriptor = descriptor[ix];
if (!table_name().is_empty() && column_descriptor.table != table_name())
continue;
if (column_descriptor.name == column_name()) {
if (index_in_row.has_value())
return Result { SQLCommand::Unknown, SQLErrorCode::AmbiguousColumnName, column_name() };
index_in_row = ix;
}
}
if (index_in_row.has_value())
return (*context.current_row)[index_in_row.value()];
return Result { SQLCommand::Unknown, SQLErrorCode::ColumnDoesNotExist, column_name() };
}
ResultOr<Value> MatchExpression::evaluate(ExecutionContext& context) const
{
switch (type()) {
case MatchOperator::Like: {
Value lhs_value = TRY(lhs()->evaluate(context));
Value rhs_value = TRY(rhs()->evaluate(context));
char escape_char = '\0';
if (escape()) {
auto escape_str = TRY(escape()->evaluate(context)).to_string();
if (escape_str.length() != 1)
return Result { SQLCommand::Unknown, SQLErrorCode::SyntaxError, "ESCAPE should be a single character" };
escape_char = escape_str[0];
}
// Compile the pattern into a simple regex.
// https://sqlite.org/lang_expr.html#the_like_glob_regexp_and_match_operators
bool escaped = false;
AK::StringBuilder builder;
builder.append('^');
for (auto c : rhs_value.to_string()) {
if (escape() && c == escape_char && !escaped) {
escaped = true;
} else if (s_posix_basic_metacharacters.contains(c)) {
escaped = false;
builder.append('\\');
builder.append(c);
} else if (c == '_' && !escaped) {
builder.append('.');
} else if (c == '%' && !escaped) {
builder.append(".*");
} else {
escaped = false;
builder.append(c);
}
}
builder.append('$');
// FIXME: We should probably cache this regex.
auto regex = Regex<PosixBasic>(builder.build());
auto result = regex.match(lhs_value.to_string(), PosixFlags::Insensitive | PosixFlags::Unicode);
return Value(invert_expression() ? !result.success : result.success);
}
case MatchOperator::Regexp: {
Value lhs_value = TRY(lhs()->evaluate(context));
Value rhs_value = TRY(rhs()->evaluate(context));
auto regex = Regex<PosixExtended>(rhs_value.to_string());
auto err = regex.parser_result.error;
if (err != regex::Error::NoError) {
StringBuilder builder;
builder.append("Regular expression: ");
builder.append(get_error_string(err));
return Result { SQLCommand::Unknown, SQLErrorCode::SyntaxError, builder.build() };
}
auto result = regex.match(lhs_value.to_string(), PosixFlags::Insensitive | PosixFlags::Unicode);
return Value(invert_expression() ? !result.success : result.success);
}
case MatchOperator::Glob:
return Result { SQLCommand::Unknown, SQLErrorCode::NotYetImplemented, "GLOB expression is not yet implemented"sv };
case MatchOperator::Match:
return Result { SQLCommand::Unknown, SQLErrorCode::NotYetImplemented, "MATCH expression is not yet implemented"sv };
default:
VERIFY_NOT_REACHED();
}
}
}
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