Eloquent\Phony\Reflection\PhpFunctionSignatureInspector::signature PHP Method

    public function signature(ReflectionFunctionAbstract $function)
    {
        $isMatch = preg_match_all(static::PARAMETER_PATTERN, $function, $matches, PREG_SET_ORDER);
        if (!$isMatch) {
            return array();
        }
        $parameters = $function->getParameters();
        $signature = array();
        $index = -1;
        foreach ($matches as $match) {
            $parameter = $parameters[++$index];
            $typehint = $match[2];
            if ('self ' === $typehint) {
                $typehint = '\\' . $parameter->getDeclaringClass()->getName() . ' ';
            } elseif ('' !== $typehint && 'array ' !== $typehint && (!$this->isCallableTypeHintSupported || 'callable ' !== $typehint) && (!$this->isIterableTypeHintSupported || 'iterable ' !== $typehint)) {
                if (!$this->isScalarTypeHintSupported) {
                    $typehint = '\\' . $typehint;
                    // @codeCoverageIgnore
                } elseif ('integer ' === $typehint && $parameter->getType()->isBuiltin()) {
                    $typehint = 'int ';
                } elseif ('boolean ' === $typehint && $parameter->getType()->isBuiltin()) {
                    $typehint = 'bool ';
                } elseif ('float ' !== $typehint && 'string ' !== $typehint) {
                    $typehint = '\\' . $typehint;
                }
            }
            if ($this->isExportReferenceSupported) {
                $byReference = $match[4];
            } else {
                $byReference = $parameter->isPassedByReference() ? '&' : '';
                // @codeCoverageIgnore
            }
            if ($this->isVariadicParameterSupported && $parameter->isVariadic()) {
                $variadic = '...';
                $optional = false;
            } else {
                $variadic = '';
                $optional = 'optional' === $match[1];
            }
            if (isset($match[6])) {
                if (' = NULL' === $match[6]) {
                    $defaultValue = ' = null';
                } else {
                    $defaultValue = ' = ' . var_export($parameter->getDefaultValue(), true);
                }
            } elseif ($optional || $match[3]) {
                $defaultValue = ' = null';
            } else {
                $defaultValue = '';
            }
            $signature[$match[5]] = array($typehint, $byReference, $variadic, $defaultValue);
        }
        return $signature;
    }