ExpressionParser - Code Metrics - Qeti/POData - Measure and Improve Code Quality continuously with Scrutinizer

ExpressionParser F
last analyzed 2017-02-19 06:57 UTC

↳ Parent: Project
Complexity

Total Complexity
Size/Duplication

Total Lines	730
Duplicated Lines	15.07 %
Coupling/Cohesion

Components	1
Dependencies	27
Importance

Changes
Metric	Value
wmc	92
lcom	1
cbo	27
dl	110
loc	730
rs	1.0434
c	0
b	0
f	0
28 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	7	1
A	hasLevel2Property()	0	4	1
A	_getCurrentToken()	0	4	1
A	_setCurrentToken()	0	4	1
A	resetParser()	0	5	1
A	parseFilter()	0	4	1
A	_parseExpression()	0	7	1
A	_parseLogicalOr()	17	17	2
A	_parseLogicalAnd()	15	15	2
A	_parseComparison()	0	17	2
A	_parseAdditive()	5	20	4
B	_parseMultiplicative()	5	26	6
B	_parseUnary()	0	36	6
A	_parsePrimary()	8	16	3
C	_parsePrimaryStart()	0	36	14
A	_parseParenExpression()	15	15	3
A	_parseIdentifier()	0	12	2
B	_parsePropertyAccess()	0	35	4
A	_parseIdentifierAsFunction()	0	11	1
A	_parseArgumentList()	17	17	4
A	_parseArguments()	8	14	3
A	_parseTypedLiteral()	0	18	2
A	_parseNullLiteral()	0	5	1
A	_tokenIdentifierIs()	0	4	1
A	_validateToken()	0	6	2
A	_recurseEnter()	0	7	2
A	_recurseLeave()	0	4	1
F	_generateComparisonExpression()	20	119	20
How to fix Duplicated Code Complexity

Duplicated Code

Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
If you have the same expression in different places: Extract expression to a method
If you have the same method in different sub-classes: Extract method, and pull up field to the parent class
If you have the same code in unrelated classes: Consider extracting the code to a new class, and injecting that class
Complex Class

Tip: Before tackling complexity, make sure that you eliminate any duplication first. This often can reduce the size of classes significantly.
Complex classes like ExpressionParser often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes. You can also have a look at the cohesion graph to spot any un-connected, or weakly-connected components.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use ExpressionParser, and based on these observations, apply Extract Interface, too.
<?php

namespace POData\UriProcessor\QueryProcessor\ExpressionParser;

use POData\Common\Messages;
use POData\Common\ODataConstants;
use POData\Common\ODataException;
use POData\Providers\Metadata\Type\Boolean;
use POData\Providers\Metadata\Type\DateTime;
use POData\Providers\Metadata\Type\Decimal;
use POData\Providers\Metadata\Type\StringType;
use POData\Providers\Metadata\Type\Int64;
use POData\Providers\Metadata\Type\Int32;
use POData\Providers\Metadata\Type\Double;
use POData\Providers\Metadata\Type\Single;
use POData\Providers\Metadata\Type\Guid;
use POData\Providers\Metadata\Type\Binary;
use POData\Providers\Metadata\Type\Null1;
use POData\Providers\Metadata\Type\INavigationType;
use POData\Providers\Metadata\Type\TypeCode;
use POData\Providers\Metadata\Type\IType;
use POData\Providers\Metadata\ResourceType;
use POData\Providers\Metadata\ResourceSet;
use POData\Providers\Metadata\ResourcePropertyKind;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\AbstractExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\PropertyAccessExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\ArithmeticExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\RelationalExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\LogicalExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\FunctionCallExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\UnaryExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\ConstantExpression;
use POData\UriProcessor\QueryProcessor\ExpressionParser\Expressions\ExpressionType;
use POData\UriProcessor\QueryProcessor\FunctionDescription;
use POData\Common\NotImplementedException;


/**
 * Class ExpressionParser
 * @package POData\UriProcessor\QueryProcessor\ExpressionParser
 */
class ExpressionParser
{
    const RECURSION_LIMIT = 200;

    /**     
     * The Lexical analyzer
     * 
     * @var ExpressionLexer
     */
    private $_lexer;
    
    /**     
     * The current recursion depth
     * 
     * @var int
     */
    private $_recursionDepth;
    
    /**
     * The ResourceType on which $filter condition needs to be applied
     * 
     * @var ResourceType
     */
    private $_resourceType;
    
    /**
     * @var bool
     */
    private $_isPHPExpressionProvider;

    /**
     * True if the filter expression contains level 2 property access, for example
     * Customers?$filter=Address/LineNumber eq 12
     * Customer?$filter=Order/OrderID gt 1234    
     * False otherwise.
     * 
     * @var bool
     */
    private $_hasLevel2PropertyInTheExpression;
    

    /**
     * Construct a new instance of ExpressionParser
     * 
     * @param string $text The expression to parse.
     * @param ResourceType $resourceType The resource type of the resource targeted by the resource path.
     * @param bool $isPHPExpressionProvider
     *
     * TODO Expression parser should not depend on the fact that end user is implementing IExpressionProvider or not.
     */
    public function __construct($text, ResourceType $resourceType, $isPHPExpressionProvider)
    {
        $this->_lexer = new ExpressionLexer($text);
        $this->_resourceType = $resourceType;
        $this->_isPHPExpressionProvider = $isPHPExpressionProvider;
        $this->_hasLevel2PropertyInTheExpression = false;
    }

    /**
     * Checks whether the expression contains level 2 property access. 
     * 
     * @return boolean
     */
    public function hasLevel2Property()
    {
        return $this->_hasLevel2PropertyInTheExpression;
    }

    /**  
     * Get the current token from lexer
     * 
     * @return ExpressionToken
     */
    private function _getCurrentToken()
    {
        return $this->_lexer->getCurrentToken();
    }

    /** 
     * Set the current token in lexer
     * 
     * @param ExpressionToken $token The token to set as current token.
     * 
     * @return void
     */
    private function _setCurrentToken($token)
    {
        $this->_lexer->setCurrentToken($token);
    }  

    /**     
     * Resets parser with new expression string.
     * 
     * @param string $text Reset the expression to parse.
     * 
     * @return void
     */
    public function resetParser($text)
    {
        $this->_lexer = new ExpressionLexer($text);
        $this->_recursionDepth = 0;
    }

    /** 
     * Parse the expression in filter option.
     * 
     * @return AbstractExpression
     */
    public function parseFilter()
    {
        return $this->_parseExpression();
    }

    /**
     * Start parsing the expression
     * 
     * @return AbstractExpression
     */
    private function _parseExpression()
    {
        $this->_recurseEnter();
        $expr = $this->_parseLogicalOr();
        $this->_recurseLeave();
        return $expr;
    }

    /** 
     * Parse logical or (or)
     * 
     * @return AbstractExpression
     */
    private function _parseLogicalOr()

    {
        $this->_recurseEnter();
        $left = $this->_parseLogicalAnd();
        while ($this->_tokenIdentifierIs(ODataConstants::KEYWORD_OR)) {
            $logicalOpToken = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();
            $right = $this->_parseLogicalAnd();
            FunctionDescription::verifyLogicalOpArguments($logicalOpToken, $left, $right);
            $left = new LogicalExpression(
                $left, $right, ExpressionType::OR_LOGICAL
            );
        }

        $this->_recurseLeave();
        return $left;
    }

    /**
     * Parse logical and (and).
     * 
     * @return AbstractExpression
     */
    private function _parseLogicalAnd()

    {
        $this->_recurseEnter();
        $left = $this->_parseComparison();
        while ($this->_tokenIdentifierIs(ODataConstants::KEYWORD_AND)) {
            $logicalOpToken = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();
            $right = $this->_parseComparison();
            FunctionDescription::verifyLogicalOpArguments($logicalOpToken, $left, $right);
            $left = new LogicalExpression($left, $right, ExpressionType::AND_LOGICAL );
        }

        $this->_recurseLeave();
        return $left;
    }

    /**
     * Parse comparison operation (eq, ne, gt, ge, lt, le)
     * 
     * @return AbstractExpression
     */
    private function _parseComparison()
    {
        $this->_recurseEnter();
        $left = $this->_parseAdditive();
        while ($this->_getCurrentToken()->isComparisonOperator()) {
            $comparisonToken = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();
            $right = $this->_parseAdditive();
            $left = self::_generateComparisonExpression(
                $left, $right, 
                $comparisonToken, $this->_isPHPExpressionProvider
            );
        }

        $this->_recurseLeave();
        return $left;
    }

    /**
     * Parse additive operation (add, sub).
     * 
     * @return AbstractExpression
     */
    private function _parseAdditive()
    {
        $this->_recurseEnter();
        $left = $this->_parseMultiplicative();
        while ($this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_ADD) 
            || $this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_SUB)) {
            $additiveToken = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();
            $right = $this->_parseMultiplicative();
            $opReturnType = FunctionDescription::verifyAndPromoteArithmeticOpArguments($additiveToken, $left, $right);
            if ($additiveToken->identifierIs(ODataConstants::KEYWORD_ADD)) {

                $left = new ArithmeticExpression($left, $right, ExpressionType::ADD, $opReturnType);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            } else {
                $left = new ArithmeticExpression($left, $right, ExpressionType::SUBTRACT, $opReturnType );
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            }
        }

        $this->_recurseLeave();
        return $left;
    }

    /** 
     * Parse multipicative operators (mul, div, mod)
     * 
     * @return AbstractExpression
     */
    private function  _parseMultiplicative()
    {
        $this->_recurseEnter();
        $left = $this->_parseUnary();
        while ($this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_MULTIPLY) 
            || $this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_DIVIDE) 
            || $this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_MODULO)
        ) {
            $multiplicativeToken = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();
            $right = $this->_parseUnary();
            $opReturnType = FunctionDescription::verifyAndPromoteArithmeticOpArguments(
                    $multiplicativeToken, $left, $right
                );
            if ($multiplicativeToken->identifierIs(ODataConstants::KEYWORD_MULTIPLY)) {
                $left = new ArithmeticExpression($left, $right, ExpressionType::MULTIPLY, $opReturnType);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            } else if ($multiplicativeToken->identifierIs(ODataConstants::KEYWORD_DIVIDE)) {

                $left = new ArithmeticExpression($left, $right, ExpressionType::DIVIDE, $opReturnType);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            } else {                
                $left = new ArithmeticExpression($left, $right, ExpressionType::MODULO, $opReturnType);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            }
        }

        $this->_recurseLeave();
        return $left;
    }

    /**
     * Parse unary operator (- ,not)
     * 
     * @return AbstractExpression
     */
    private function _parseUnary()
    {
        $this->_recurseEnter();
       
        if ($this->_getCurrentToken()->Id == ExpressionTokenId::MINUS 
            || $this->_getCurrentToken()->identifierIs(ODataConstants::KEYWORD_NOT)
        ) {
            $op = clone $this->_getCurrentToken();
            $this->_lexer->nextToken();            
            if ($op->Id == ExpressionTokenId::MINUS 
                && (ExpressionLexer::isNumeric($this->_getCurrentToken()->Id))
            ) {
                $numberLiteral = $this->_getCurrentToken();
                $numberLiteral->Text = '-' . $numberLiteral->Text;
                $numberLiteral->Position = $op->Position;
                $v = $this->_getCurrentToken();
$myVar = 'Value';
$higher = false;

if (rand(1, 6) > 3) {
    $higher = true;
} else {
    $higher = false;
}
                $this->_setCurrentToken($numberLiteral);
                $this->_recurseLeave();
                return $this->_parsePrimary();
            }

            $expr = $this->_parsePrimary();
            FunctionDescription::validateUnaryOpArguments($op, $expr);
            if ($op->Id == ExpressionTokenId::MINUS) {
                $expr = new UnaryExpression($expr, ExpressionType::NEGATE, $expr->getType());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            } else {
                $expr = new UnaryExpression($expr, ExpressionType::NOT_LOGICAL, new Boolean());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
            }

            $this->_recurseLeave();
            return $expr;
        }

        $this->_recurseLeave();
        return $this->_parsePrimary();
    }

    /**
     * Start parsing the primary.
     *  
     * @return AbstractExpression
     */
    private function _parsePrimary()
    {
        $this->_recurseEnter();
        $expr = $this->_parsePrimaryStart();
        while (true) {

            if ($this->_getCurrentToken()->Id == ExpressionTokenId::SLASH) {
                $this->_lexer->nextToken();
                $expr = $this->_parsePropertyAccess($expr);

            } else {
                break;
            }
        }

        $this->_recurseLeave();
        return $expr;
    }

    /** 
     * Parse primary tokens [literals, identifiers (e.g. function call), open param for sub expressions]
     *
     * 
     * @return AbstractExpression
     */
    private function _parsePrimaryStart()
    {
        switch ($this->_lexer->getCurrentToken()->Id) {
        case ExpressionTokenId::BOOLEAN_LITERAL:
            return $this->_parseTypedLiteral(new Boolean());
        case ExpressionTokenId::DATETIME_LITERAL:
            return $this->_parseTypedLiteral(new DateTime());
        case ExpressionTokenId::DECIMAL_LITERAL:
            return $this->_parseTypedLiteral(new Decimal());
        case ExpressionTokenId::NULL_LITERAL:
            return $this->_parseNullLiteral();
        case ExpressionTokenId::IDENTIFIER:
            return $this->_parseIdentifier();
        case ExpressionTokenId::STRING_LITERAL:
            return $this->_parseTypedLiteral(new StringType());
        case ExpressionTokenId::INT64_LITERAL:
            return $this->_parseTypedLiteral(new Int64());
        case ExpressionTokenId::INTEGER_LITERAL:
            return $this->_parseTypedLiteral(new Int32());
        case ExpressionTokenId::DOUBLE_LITERAL:
            return $this->_parseTypedLiteral(new Double());
        case ExpressionTokenId::SINGLE_LITERAL:
            return $this->_parseTypedLiteral(new Single());
        case ExpressionTokenId::GUID_LITERAL:
            return $this->_parseTypedLiteral(new Guid());
        case ExpressionTokenId::BINARY_LITERAL:
            throw new NotImplementedException(
                'Support for binary is not implemented'
            );
            //return $this->_parseTypedLiteral(new Binary());

        case ExpressionTokenId::OPENPARAM:
            return $this->_parseParenExpression();
        default:
            throw ODataException::createSyntaxError("Expression expected.");
        }
    }

    /** 
     * Parse Sub expression.
     * 
     * @return AbstractExpression
     */
    private function _parseParenExpression()

    {
        if ($this->_getCurrentToken()->Id != ExpressionTokenId::OPENPARAM) {
            throw ODataException::createSyntaxError("Open parenthesis expected.");
        }

        $this->_lexer->nextToken();
        $expr = $this->_parseExpression();
        if ($this->_getCurrentToken()->Id != ExpressionTokenId::CLOSEPARAM) {
            throw ODataException::createSyntaxError("Close parenthesis expected.");
        }

        $this->_lexer->nextToken();
        return $expr;
    }

    /**
     * Parse an identifier
     * 
     * @return AbstractExpression
     */
    private function _parseIdentifier()
    {
        $this->_validateToken(ExpressionTokenId::IDENTIFIER);

        // An open paren here would indicate calling a method        
        $identifierIsFunction = $this->_lexer->peekNextToken()->Id == ExpressionTokenId::OPENPARAM;
        if ($identifierIsFunction) {
            return $this->_parseIdentifierAsFunction();
        } else {
            return $this->_parsePropertyAccess(null);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        }
    }

    /**
     * Parse a property access
     * 
     * @param PropertyAccessExpression $parentExpression Parent expression.
     * 
     * @throws ODataException
     * 
     * @return PropertyAccessExpression
     */
    private function _parsePropertyAccess($parentExpression)
    {
        $identifier = $this->_getCurrentToken()->getIdentifier(); 
        if (is_null($parentExpression)) {
            $parentResourceType = $this->_resourceType;
        } else {
            $parentResourceType = $parentExpression->getResourceType();
            $this->_hasLevel2PropertyInTheExpression = true;
        }

        $resourceProperty = $parentResourceType->resolveProperty($identifier);
        if (is_null($resourceProperty)) {
            throw ODataException::createSyntaxError(
                Messages::expressionLexerNoPropertyInType(
                    $identifier, 
                    $parentResourceType->getFullName(), 
                    $this->_getCurrentToken()->Position
                )
            );
        }

        if ($resourceProperty->getKind() == ResourcePropertyKind::RESOURCESET_REFERENCE) {
            throw ODataException::createSyntaxError(
                Messages::expressionParserEntityCollectionNotAllowedInFilter(
                    $resourceProperty->getName(), 
                    $parentResourceType->getFullName(), 
                    $this->_getCurrentToken()->Position
                )
            );
        }

        $exp = new PropertyAccessExpression($parentExpression, $resourceProperty); 
/** @return stdClass|null */
function mayReturnNull() { }

function doesNotAcceptNull(stdClass $x) { }

// With potential error.
function withoutCheck() {
    $x = mayReturnNull();
    doesNotAcceptNull($x); // Potential error here.
}

// Safe - Alternative 1
function withCheck1() {
    $x = mayReturnNull();
    if ( ! $x instanceof stdClass) {
        throw new \LogicException('$x must be defined.');
    }
    doesNotAcceptNull($x);
}

// Safe - Alternative 2
function withCheck2() {
    $x = mayReturnNull();
    if ($x instanceof stdClass) {
        doesNotAcceptNull($x);
    }
}
        $this->_lexer->nextToken();
        return $exp;
    }

    /** 
     * Try to parse an identifier which is followed by an opern bracket as
     * astoria URI function call.
     * 
     * @return AbstractExpression
     * 
     * @throws ODataException
     */
    private function _parseIdentifierAsFunction()
    {
        $functionToken = clone $this->_getCurrentToken();
        $functions = FunctionDescription::verifyFunctionExists($functionToken);
        $this->_lexer->nextToken();
        $paramExpressions = $this->_parseArgumentList();
        $function = FunctionDescription::verifyFunctionCallOpArguments(
            $functions, $paramExpressions, $functionToken
        );
        return new FunctionCallExpression($function, $paramExpressions);
    }

    /**
     * Start parsing argument list of a function-call
     * 
     * @return array<AbstractExpression>
     */
    private function _parseArgumentList()

    {
        if ($this->_getCurrentToken()->Id != ExpressionTokenId::OPENPARAM) {
            throw ODataException::createSyntaxError("Open parenthesis expected.");
        }

        $this->_lexer->nextToken();
        $args 
            = $this->_getCurrentToken()->Id != ExpressionTokenId::CLOSEPARAM 
             ? $this->_parseArguments() : array();
        if ($this->_getCurrentToken()->Id != ExpressionTokenId::CLOSEPARAM) {
            throw ODataException::createSyntaxError("Close parenthesis expected.");
        }

        $this->_lexer->nextToken();
        return $args;
    }

    /** 
     * Parse arguments of  a function-call.
     * 
     * @return array<AbstractExpression>
     */
    private function _parseArguments()
    {
        $argList = array();
        while (true) {

            $argList[] = $this->_parseExpression();
            if ($this->_getCurrentToken()->Id != ExpressionTokenId::COMMA) {
                break;
            }

            $this->_lexer->nextToken();
        }

        return $argList;
    }

    /**
     * Parse primitive type literal.
     * 
     * @param IType $targetType Expected type of the current literal.
     * 
     * @return AbstractExpression
     * 
     * @throws ODataException
     */
    private function _parseTypedLiteral(IType $targetType)
    {
        $literal = $this->_lexer->getCurrentToken()->Text;
        $outVal = null;
        if (!$targetType->validate($literal, $outVal)) {
            throw ODataException::createSyntaxError(
                Messages::expressionParserUnrecognizedLiteral(
                    $targetType->getFullTypeName(), 
                    $literal, 
                    $this->_lexer->getCurrentToken()->Position
                )
            );
        }

        $result = new ConstantExpression($outVal, $targetType);
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        $this->_lexer->nextToken();
        return $result;
    }

    /**
     * Parse null literal.
     * 
     * @return ConstantExpression
     */
    private function _parseNullLiteral()
    {
        $this->_lexer->nextToken();
        return new ConstantExpression(null, new Null1());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
    }

    /**
     * Check the current token is of a specific kind
     * 
     * @param ExpressionTokenId $expressionTokenId Token to check 
     *                                             with current token.
     * 
     * @return boolean
     */
    private function _tokenIdentifierIs($expressionTokenId)
    {
        return $this->_getCurrentToken()->identifierIs($expressionTokenId);
    }

    /**
     * Validate the current token
     * 
     * @param ExpressionTokenId $expressionTokenId Token to check 
     *                                             with current token.
     * 
     * @return void 
     * 
     * @throws ODataException
     */
    private function _validateToken($expressionTokenId)
    {
        if ($this->_getCurrentToken()->Id != $expressionTokenId) {
            throw ODataException::createSyntaxError("Syntax error.");
        }
    }

    /**
     * Increment recursion count and throw error if beyond limit
     * 
     * @return void 
     * 
     * @throws ODataException If max recursion limit hits.
     */
    private function _recurseEnter()
    {
        $this->_recursionDepth++;
        if ($this->_recursionDepth == self::RECURSION_LIMIT) {
            throw ODataException::createSyntaxError("Recursion limit reached.");
        }
    }

    /**
     * Decrement recursion count
     * 
     * @return void
     */
    private function _recurseLeave()
    {
        $this->_recursionDepth--;
    }

    /**
     * Generates Comparison Expression
     * 
     * @param AbstractExpression $left                       The LHS expression.
     * @param AbstractExpression $right                      The RHS expression.
     * @param ExpressionToken    $expressionToken            The comparison expression token.
     * @param boolean            $isPHPExpressionProvider
     * 
     * @return AbstractExpression
     */
    private static function _generateComparisonExpression($left, $right, $expressionToken, $isPHPExpressionProvider)
    {
        FunctionDescription::verifyRelationalOpArguments($expressionToken, $left, $right);

        //We need special handling for comparison of following types:
        //1. String
        //2. DateTime
        //3. Guid
        //4. Binary
        //Will make these comparison as function calls, which will 
        // be converted to language specific function call by expression 
        // provider
        $string = new StringType();
        if ($left->typeIs($string) && $right->typeIs($string)) {

            $strcmpFunctions = FunctionDescription::stringComparisonFunctions();
            $left = new FunctionCallExpression($strcmpFunctions[0], array($left, $right));
            $right = new ConstantExpression(0, new Int32());  
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        }

        $dateTime = new DateTime();
        if ($left->typeIs($dateTime) && $right->typeIs($dateTime)) {

            $dateTimeCmpFunctions = FunctionDescription::dateTimeComparisonFunctions();
            $left = new FunctionCallExpression( $dateTimeCmpFunctions[0], array($left, $right));
            $right = new ConstantExpression(0, new Int32());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        }

        $guid = new Guid();
        if ($left->typeIs($guid) && $right->typeIs($guid)) {

            $guidEqualityFunctions = FunctionDescription::guidEqualityFunctions();
            $left = new FunctionCallExpression($guidEqualityFunctions[0], array($left, $right));
            $right = new ConstantExpression(true, new Boolean());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        }

        $binary = new Binary();
        if ($left->typeIs($binary) && $right->typeIs($binary)) {

            $binaryEqualityFunctions = FunctionDescription::binaryEqualityFunctions();
            $left = new FunctionCallExpression($binaryEqualityFunctions[0], array($left, $right));
            $right = new ConstantExpression(true, new Boolean());
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
        }

        $null = new Null1();
        if ($left->typeIs($null) || $right->typeIs($null)) {
          // If the end user is responsible for implementing IExpressionProvider
          // then the sub-tree for a nullability check would be:
          //
          //          RelationalExpression(EQ/NE)
          //                    |
          //               ------------
          //               |           |
          //               |           |
          //            CustomerID    NULL
          //
          // Otherwise (In case of default PHPExpressionProvider):
          //          
          //  CustomerID eq null
          //  ==================
          //
          //              FunctionCallExpression(is_null)
          //                       |
          //                       |- Signature => bool (typeof(CustomerID))

          //                       |- args => {CustomerID}

          //
          //
          //  CustomerID ne null
          //  ==================
          //
          //              UnaryExpression (not)
          //                       |
          //              FunctionCallExpression(is_null)
          //                       |
          //                       |- Signature => bool (typeof(CustomerID))

          //                       |- args => {CustomerID}

          //
            if ($isPHPExpressionProvider) {
                $arg = $left->typeIs($null) ? $right : $left;
                $isNullFunctionDescription = new FunctionDescription('is_null', new Boolean(), array($arg->getType()));
                switch ($expressionToken->Text) {
	                case ODataConstants::KEYWORD_EQUAL:
	                    return new FunctionCallExpression($isNullFunctionDescription, array($arg));
	                    break;
switch ($x) {
    case 1:
        return 'foo';
        break; // This break is not necessary and can be left off.
}

	                case ODataConstants::KEYWORD_NOT_EQUAL:
	                    return new UnaryExpression(
	                        new FunctionCallExpression($isNullFunctionDescription, array($arg)),
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
	                        ExpressionType::NOT_LOGICAL,
	                        new Boolean()
function acceptsInteger($int) { }

$x = '123'; // string "123"

// Instead of
acceptsInteger($x);

// we recommend to use
acceptsInteger((integer) $x);
	                    );
	                    break;
switch ($x) {
    case 1:
        return 'foo';
        break; // This break is not necessary and can be left off.
}
                }
            }
        }

        switch ($expressionToken->Text) {
	        case ODataConstants::KEYWORD_EQUAL:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::EQUAL
	            );
	        case ODataConstants::KEYWORD_NOT_EQUAL:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::NOTEQUAL
	            );
	        case ODataConstants::KEYWORD_GREATERTHAN:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::GREATERTHAN
	            );
	        case ODataConstants::KEYWORD_GREATERTHAN_OR_EQUAL:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::GREATERTHAN_OR_EQUAL
	            );
	        case ODataConstants::KEYWORD_LESSTHAN:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::LESSTHAN
	            );
	        default:
	            return new RelationalExpression(
	                $left, $right, ExpressionType::LESSTHAN_OR_EQUAL
	            );
        }
    }

}
Qeti / POData

ExpressionParser F last analyzed 2017-02-19 06:57 UTC
