PDepend\Source\Language\PHP\AbstractPHPParser::parseOptionalExpression PHP Method

parseOptionalExpression() protected method

This method optionally parses an expression node and returns it. When no expression was found this method will return null.
Since: 0.9.6
protected parseOptionalExpression ( ) : PDepend\Source\AST\ASTNode
return PDepend\Source\AST\ASTNode
    protected function parseOptionalExpression()
    {
        $expressions = array();
        while (($tokenType = $this->tokenizer->peek()) != Tokenizer::T_EOF) {
            $expr = null;
            switch ($tokenType) {
                case Tokens::T_COMMA:
                case Tokens::T_AS:
                case Tokens::T_BREAK:
                case Tokens::T_CLOSE_TAG:
                case Tokens::T_COLON:
                case Tokens::T_CONTINUE:
                case Tokens::T_CURLY_BRACE_CLOSE:
                case Tokens::T_DECLARE:
                case Tokens::T_DO:
                case Tokens::T_DOUBLE_ARROW:
                case Tokens::T_ECHO:
                case Tokens::T_END_HEREDOC:
                case Tokens::T_ENDFOREACH:
                case Tokens::T_FOR:
                case Tokens::T_FOREACH:
                case Tokens::T_GLOBAL:
                case Tokens::T_GOTO:
                case Tokens::T_IF:
                case Tokens::T_PARENTHESIS_CLOSE:
                case Tokens::T_RETURN:
                case Tokens::T_SEMICOLON:
                case Tokens::T_SQUARED_BRACKET_CLOSE:
                case Tokens::T_SWITCH:
                case Tokens::T_THROW:
                case Tokens::T_TRY:
                case Tokens::T_UNSET:
                case Tokens::T_WHILE:
                    break 2;
                case Tokens::T_SELF:
                case Tokens::T_STRING:
                case Tokens::T_PARENT:
                case Tokens::T_STATIC:
                case Tokens::T_DOLLAR:
                case Tokens::T_VARIABLE:
                case Tokens::T_BACKSLASH:
                case Tokens::T_NAMESPACE:
                    $expressions[] = $this->parseVariableOrConstantOrPrimaryPrefix();
                    break;
                case $this->isArrayStartDelimiter():
                    $expressions[] = $this->doParseArray();
                    break;
                case Tokens::T_NULL:
                case Tokens::T_TRUE:
                case Tokens::T_FALSE:
                case Tokens::T_LNUMBER:
                case Tokens::T_DNUMBER:
                case Tokens::T_BACKTICK:
                case Tokens::T_DOUBLE_QUOTE:
                case Tokens::T_CONSTANT_ENCAPSED_STRING:
                    $expressions[] = $this->parseLiteralOrString();
                    break;
                case Tokens::T_NEW:
                    $expressions[] = $this->parseAllocationExpression();
                    break;
                case Tokens::T_EVAL:
                    $expressions[] = $this->parseEvalExpression();
                    break;
                case Tokens::T_CLONE:
                    $expressions[] = $this->parseCloneExpression();
                    break;
                case Tokens::T_INSTANCEOF:
                    $expressions[] = $this->parseInstanceOfExpression();
                    break;
                case Tokens::T_ISSET:
                    $expressions[] = $this->parseIssetExpression();
                    break;
                case Tokens::T_LIST:
                    $expressions[] = $this->parseListExpression();
                    break;
                case Tokens::T_QUESTION_MARK:
                    $expressions[] = $this->parseConditionalExpression();
                    break;
                case Tokens::T_BOOLEAN_AND:
                    $expressions[] = $this->parseBooleanAndExpression();
                    break;
                case Tokens::T_BOOLEAN_OR:
                    $expressions[] = $this->parseBooleanOrExpression();
                    break;
                case Tokens::T_LOGICAL_AND:
                    $expressions[] = $this->parseLogicalAndExpression();
                    break;
                case Tokens::T_LOGICAL_OR:
                    $expressions[] = $this->parseLogicalOrExpression();
                    break;
                case Tokens::T_LOGICAL_XOR:
                    $expressions[] = $this->parseLogicalXorExpression();
                    break;
                case Tokens::T_FUNCTION:
                    $expressions[] = $this->parseClosureDeclaration();
                    break;
                case Tokens::T_PARENTHESIS_OPEN:
                    $expressions[] = $this->parseParenthesisExpressionOrPrimaryPrefix();
                    break;
                case Tokens::T_EXIT:
                    $expressions[] = $this->parseExitExpression();
                    break;
                case Tokens::T_START_HEREDOC:
                    $expressions[] = $this->parseHeredoc();
                    break;
                case Tokens::T_CURLY_BRACE_OPEN:
                    $expressions[] = $this->parseBraceExpression($this->builder->buildAstExpression(), $this->consumeToken(Tokens::T_CURLY_BRACE_OPEN), Tokens::T_CURLY_BRACE_CLOSE);
                    break;
                case Tokens::T_INCLUDE:
                    $expressions[] = $this->parseIncludeExpression();
                    break;
                case Tokens::T_INCLUDE_ONCE:
                    $expressions[] = $this->parseIncludeOnceExpression();
                    break;
                case Tokens::T_REQUIRE:
                    $expressions[] = $this->parseRequireExpression();
                    break;
                case Tokens::T_REQUIRE_ONCE:
                    $expressions[] = $this->parseRequireOnceExpression();
                    break;
                case Tokens::T_DEC:
                    $expressions[] = $this->parseDecrementExpression($expressions);
                    break;
                case Tokens::T_INC:
                    $expressions[] = $this->parseIncrementExpression($expressions);
                    break;
                case Tokens::T_SL:
                    $expressions[] = $this->parseShiftLeftExpression();
                    break;
                case Tokens::T_SR:
                    $expressions[] = $this->parseShiftRightExpression();
                    break;
                case Tokens::T_DIR:
                case Tokens::T_FILE:
                case Tokens::T_LINE:
                case Tokens::T_NS_C:
                case Tokens::T_FUNC_C:
                case Tokens::T_CLASS_C:
                case Tokens::T_METHOD_C:
                    $expressions[] = $this->parseConstant();
                    break;
                case Tokens::T_INT_CAST:
                case Tokens::T_BOOL_CAST:
                case Tokens::T_ARRAY_CAST:
                case Tokens::T_UNSET_CAST:
                case Tokens::T_OBJECT_CAST:
                case Tokens::T_DOUBLE_CAST:
                case Tokens::T_STRING_CAST:
                    $expressions[] = $this->parseCastExpression();
                    break;
                case Tokens::T_EQUAL:
                case Tokens::T_OR_EQUAL:
                case Tokens::T_SL_EQUAL:
                case Tokens::T_SR_EQUAL:
                case Tokens::T_AND_EQUAL:
                case Tokens::T_DIV_EQUAL:
                case Tokens::T_MOD_EQUAL:
                case Tokens::T_MUL_EQUAL:
                case Tokens::T_XOR_EQUAL:
                case Tokens::T_PLUS_EQUAL:
                case Tokens::T_MINUS_EQUAL:
                case Tokens::T_CONCAT_EQUAL:
                    $expressions[] = $this->parseAssignmentExpression(array_pop($expressions));
                    break;
                    // TODO: Handle comments here
                // TODO: Handle comments here
                case Tokens::T_COMMENT:
                case Tokens::T_DOC_COMMENT:
                    $this->consumeToken($tokenType);
                    break;
                case Tokens::T_PRINT:
                    // TODO: Implement print expression
                    $token = $this->consumeToken($tokenType);
                    $expr = $this->builder->buildAstPrintExpression();
                    $expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
                    $expressions[] = $expr;
                    break;
                case Tokens::T_STRING_VARNAME:
                    // TODO: Implement this
                // TODO: Implement this
                case Tokens::T_PLUS:
                    // TODO: Make this a arithmetic expression
                // TODO: Make this a arithmetic expression
                case Tokens::T_MINUS:
                case Tokens::T_MUL:
                case Tokens::T_DIV:
                case Tokens::T_MOD:
                case Tokens::T_IS_EQUAL:
                    // TODO: Implement compare expressions
                // TODO: Implement compare expressions
                case Tokens::T_IS_NOT_EQUAL:
                case Tokens::T_IS_IDENTICAL:
                case Tokens::T_IS_NOT_IDENTICAL:
                case Tokens::T_IS_GREATER_OR_EQUAL:
                case Tokens::T_IS_SMALLER_OR_EQUAL:
                case Tokens::T_ANGLE_BRACKET_OPEN:
                case Tokens::T_ANGLE_BRACKET_CLOSE:
                case Tokens::T_EMPTY:
                case Tokens::T_CONCAT:
                case Tokens::T_BITWISE_OR:
                case Tokens::T_BITWISE_AND:
                case Tokens::T_BITWISE_NOT:
                case Tokens::T_BITWISE_XOR:
                    $token = $this->consumeToken($tokenType);
                    $expr = $this->builder->buildAstExpression($token->image);
                    $expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
                    $expressions[] = $expr;
                    break;
                case Tokens::T_AT:
                case Tokens::T_EXCLAMATION_MARK:
                    $token = $this->consumeToken($tokenType);
                    $expr = $this->builder->buildAstUnaryExpression($token->image);
                    $expr->configureLinesAndColumns($token->startLine, $token->endLine, $token->startColumn, $token->endColumn);
                    $expressions[] = $expr;
                    break;
                case Tokens::T_YIELD:
                    $expressions[] = $this->parseYield();
                    break;
                default:
                    $expressions[] = $this->parseOptionalExpressionForVersion();
                    break;
            }
        }
        $expressions = $this->reduce($expressions);
        $count = count($expressions);
        if ($count == 0) {
            return null;
        } elseif ($count == 1) {
            return $expressions[0];
        }
        $expr = $this->builder->buildAstExpression();
        foreach ($expressions as $node) {
            $expr->addChild($node);
        }
        $expr->configureLinesAndColumns($expressions[0]->getStartLine(), $expressions[$count - 1]->getEndLine(), $expressions[0]->getStartColumn(), $expressions[$count - 1]->getEndColumn());
        return $expr;
    }
AbstractPHPParser