function parseCaseBase(&$source, &$base, &$cases, &$default)
{
$base_name = generate_name("case_base");
$base_value = $base->type() . " " . $base_name . " = " . $base->value() . ";";
$retType = null;
$retSource = null;
$prep = [];
$value_name = generate_name("case_value");
$info = new ExpressionInfo($source, null, $value_name, true);
$info->absorbMeta($base);
grokit_logic_assert(count($cases) > 0, 'No cases found for case statement with base at ' . $source);
// Handle cases
foreach ($cases as $case) {
$test = parseExpression(ast_get($case, NodeKey::TEST));
$expr = parseExpression(ast_get($case, NodeKey::EXPR));
$first = false;
// TODO: Test if == operator exists between test and base
// If the return type is not set, set it.
// Otherwise, make sure that the expression's return type is compatible
// with the already set return type.
if ($retType === null) {
$retType = $expr->type();
$retSource = $expr->source();
$first = true;
$info->setType($retType);
} else {
if (canConvert($expr->type(), $retType)) {
// They aren't the same but we can perform an implicit conversion
// to make them the same, so do so.
$expr = convertExpression($expr, $retType, $retSource);
} else {
// Incompatible types.
grokit_error('Case return type ' . $expr->type() . ' of expression at ' . $expr->source() . ' incompatible with previous return type ' . $retType . ' defined by expression at ' . $retSource);
}
}
$info->absorbMeta($test);
$info->absorbMeta($expr);
$myPrep = '';
if (!$first) {
$myPrep .= 'else ';
}
$myPrep .= "if( {$base_name} == {$test->value()} ) {$value_name} = {$expr->value()};";
$prep[] = $myPrep;
}
// Handle default
if ($default !== null) {
if (canConvert($default->type(), $retType)) {
$default = convertExpression($default, $retType, $retSource);
} else {
// Incompatible types.
grokit_error('Case return type ' . $default->type() . ' of default at ' . $default->source() . ' incompatible with previous return type ' . $retType . ' defined by expression at ' . $retSource);
}
$info->absorbMeta($default);
$prep[] = "else {$value_name} = {$default->value()};";
}
// Prepend the declaration of the variable that holds the return value of the case.
array_unshift($prep, "{$retType} {$value_name};");
// If base expression is constant, add to constants, otherwise to preprocessing.
if ($base->is_const()) {
$info->addConstant($base_value);
} else {
$info->addPreprocess($base_value);
}
$info->addPreprocesses($prep);
// If everything was constant, transform the expression into a constant
if ($info->is_const()) {
$info->makeConstant();
}
$testRetType = lookupType('bool');
}
