src/Parser/VariableParser.php
private function assignVariableParameterDefault($variable, $default, $empty, $type)
    {
        $default = $this->parser->value_parser->parse($default);

        if ($type === "assign_default_value" && $empty) {
            $this->parser->lines[$variable] = $default;
        }

        return $default;
    }
private function assignVariableParameterDefault($variable, $default, $empty, $type)
    {
        $default = $this->parser->value_parser->parse($default);

        if ($type === "assign_default_value" && $empty) {
            $this->parser->lines[$variable] = $default;
        }

        return $default;
    }
Parses and sets the variable parameter to default

@param string $variable The variable to parse
@param string $default  The default value
@param bool   $empty    Is there the variable empty if exists and the empty flag is set
@param string $type     The type of parameter expansion

@return string The parsed default value