private function parseParameterFn()

in src/Parser.php [821:863]
35 lines of code
8 McCabe index (conditional complexity)

    private function parseParameterFn() {
        return function ($parentNode) {
            $parameter = new Parameter();
            $parameter->parent = $parentNode;
            if ($this->token->kind === TokenKind::AttributeToken) {
                $parameter->attributes = $this->parseAttributeGroups($parameter);
            }
            // Note that parameter modifiers are allowed to be repeated by the parser in php 8.1 (it is a compiler error)
            //
            // TODO: Remove the visibilityToken in a future backwards incompatible release
            $parameter->visibilityToken = $this->eatOptional([TokenKind::PublicKeyword, TokenKind::ProtectedKeyword, TokenKind::PrivateKeyword]);
            $parameter->modifiers = $this->parseParameterModifiers() ?: null;

            $parameter->questionToken = $this->eatOptional1(TokenKind::QuestionToken);
            $parameter->typeDeclarationList = $this->tryParseParameterTypeDeclarationList($parameter);
            if ($parameter->typeDeclarationList) {
                $children = $parameter->typeDeclarationList->children;
                if (end($children) instanceof MissingToken && ($children[\count($children) - 2]->kind ?? null) === TokenKind::AmpersandToken) {
                    array_pop($parameter->typeDeclarationList->children);
                    $parameter->byRefToken = array_pop($parameter->typeDeclarationList->children);
                    if (!$parameter->typeDeclarationList->children) {
                        $parameter->typeDeclarationList = null;
                    }
                }
            } elseif ($parameter->questionToken) {
                // TODO ParameterType?
                $parameter->typeDeclarationList = new MissingToken(TokenKind::PropertyType, $this->token->fullStart);
            }
            if (!$parameter->byRefToken) {
                $parameter->byRefToken = $this->eatOptional1(TokenKind::AmpersandToken);
            }
            // TODO add post-parse rule that prevents assignment
            // TODO add post-parse rule that requires only last parameter be variadic
            $parameter->dotDotDotToken = $this->eatOptional1(TokenKind::DotDotDotToken);
            $parameter->variableName = $this->eat1(TokenKind::VariableName);
            $parameter->equalsToken = $this->eatOptional1(TokenKind::EqualsToken);
            if ($parameter->equalsToken !== null) {
                // TODO add post-parse rule that checks for invalid assignments
                $parameter->default = $this->parseExpression($parameter);
            }
            return $parameter;
        };
    }