Parser::parseExpression() - Code Metrics - Inspection of "Several fixes + integration test" - uuf6429/expression-language-arrowfunc - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 8cc02b...5173bc )

by Christian

created 2016-10-30 17:19 UTC

Parser::parseExpression() B

↳ Parent: Parser

Complexity

Conditions	6
Paths	4

Size

Total Lines	20
Code Lines	12

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	12
CRAP Score	6

Importance

Changes

Metric	Value
dl	0
loc	20
ccs	12
cts	12
cp	1
rs	8.8571
c	0
b	0
f	0
cc	6
eloc	12
nc	4
nop	1
crap	6

<?php

namespace uuf6429\ExpressionLanguage;

use uuf6429\ExpressionLanguage\Node\ArrowFuncNode;
use Symfony\Component\ExpressionLanguage\Node\ArgumentsNode;
use Symfony\Component\ExpressionLanguage\Node\ArrayNode;
use Symfony\Component\ExpressionLanguage\Node\BinaryNode;
use Symfony\Component\ExpressionLanguage\Node\ConditionalNode;
use Symfony\Component\ExpressionLanguage\Node\ConstantNode;
use Symfony\Component\ExpressionLanguage\Node\FunctionNode;
use Symfony\Component\ExpressionLanguage\Node\GetAttrNode;
use Symfony\Component\ExpressionLanguage\Node\NameNode;
use Symfony\Component\ExpressionLanguage\Node\Node;
use Symfony\Component\ExpressionLanguage\Node\UnaryNode;
use Symfony\Component\ExpressionLanguage\Token;
use Symfony\Component\ExpressionLanguage\SyntaxError;

class Parser
{
    const OPERATOR_LEFT = 1;
    const OPERATOR_RIGHT = 2;

    const TOKEN_REPLACEMENT_TYPE = 'replacement';

    /** @var TokenStream */
    private $stream;

    /** @var array */
    private $unaryOperators;

    /** @var array */
    private $binaryOperators;

    /** @var array */
    private $functions;

    /** @var string[] */
    private $names;

    /** @var Node[] */
    private $replacementNodes;

    public function __construct(array $functions)
    {
        $this->functions = $functions;

        $this->unaryOperators = array(
            'not' => array('precedence' => 50),
            '!' => array('precedence' => 50),
            '-' => array('precedence' => 500),
            '+' => array('precedence' => 500),
        );
        $this->binaryOperators = array(
            '->' => array('precedence' => 5, 'associativity' => self::OPERATOR_LEFT),
            'or' => array('precedence' => 10, 'associativity' => self::OPERATOR_LEFT),
            '||' => array('precedence' => 10, 'associativity' => self::OPERATOR_LEFT),
            'and' => array('precedence' => 15, 'associativity' => self::OPERATOR_LEFT),
            '&&' => array('precedence' => 15, 'associativity' => self::OPERATOR_LEFT),
            '|' => array('precedence' => 16, 'associativity' => self::OPERATOR_LEFT),
            '^' => array('precedence' => 17, 'associativity' => self::OPERATOR_LEFT),
            '&' => array('precedence' => 18, 'associativity' => self::OPERATOR_LEFT),
            '==' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '===' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '!=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '!==' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '<' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '>' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '>=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '<=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            'not in' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            'in' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            'matches' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
            '..' => array('precedence' => 25, 'associativity' => self::OPERATOR_LEFT),
            '+' => array('precedence' => 30, 'associativity' => self::OPERATOR_LEFT),
            '-' => array('precedence' => 30, 'associativity' => self::OPERATOR_LEFT),
            '~' => array('precedence' => 40, 'associativity' => self::OPERATOR_LEFT),
            '*' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
            '/' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
            '%' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
            '**' => array('precedence' => 200, 'associativity' => self::OPERATOR_RIGHT),
        );

        $this->replacementNodes = array();
    }

    /**
     * Converts a token stream to a node tree.
     *
     * The valid names is an array where the values
     * are the names that the user can use in an expression.
     *
     * If the variable name in the compiled PHP code must be
     * different, define it as the key.
     *
     * For instance, ['this' => 'container'] means that the
     * variable 'container' can be used in the expression
     * but the compiled code will use 'this'.
     *
     * @param TokenStream $stream A token stream instance
     * @param array       $names  An array of valid names
     *
     * @return Node A node tree
     *
     * @throws SyntaxError
     */
    public function parse(TokenStream $stream, $names = array())
    {
        $this->names = $names;

        $stream = $this->preParseArrowFuncs($stream);

        $this->stream = $stream;
        $node = $this->parseExpression();

        if (!$stream->isEOF()) {

            throw new SyntaxError(
                sprintf(
                    'Unexpected token "%s" of value "%s"',
                    $stream->current->type,
                    $stream->current->value
                ),
                $stream->current->cursor
            );
        }

        return $node;
    }

    /**
     * Replaces all anonymous functions with placeholder tokens.
     *
     * @param TokenStream $stream
     *
     * @return TokenStream
     */
    protected function preParseArrowFuncs(TokenStream $stream)
    {
        while (!$stream->isEOF()) {
            if ($stream->current->test(Token::OPERATOR_TYPE, '->')) {
                $operatorPos = $stream->position();
                $operatorCursor = $stream->current->cursor;
                $replacementNodeIndex = count($this->replacementNodes);
                $this->replacementNodes[$replacementNodeIndex] = null;

                // parse parameters
                $parameterNames = array();
                $parameterNodes = array();
                $expectParam = true;
                $stream->prev();
                $stream->expectPrev(Token::PUNCTUATION_TYPE, ')', 'Parameter list must end with parenthesis');
                while (!$stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
                    if ($expectParam) {
                        $stream->current->test(Token::NAME_TYPE);
                        array_unshift($parameterNames, $stream->current->value);
                        array_unshift($parameterNodes, new NameNode($stream->current->value));
                        $stream->prev();
                    } else {
                        $stream->expectPrev(Token::PUNCTUATION_TYPE, ',', 'Parameters must be separated by a comma');
                    }
                    $expectParam = !$expectParam;
                }
                $startPos = $stream->position();

                // parse body
                $stream->seek($operatorPos, SEEK_SET);
                $stream->next();
                $stream->expect(Token::PUNCTUATION_TYPE, '{', 'Anonymous function body must start with a curly bracket');
                $bodyTokens = array();
                $openingBracketCount = 1;
                while ($openingBracketCount != 0) {
                    if ($stream->current->test(Token::PUNCTUATION_TYPE, '{')) {
                        ++$openingBracketCount;
                    }

                    if ($stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
                        --$openingBracketCount;
                    }

                    if (!$openingBracketCount) {
                        $currentNames = $this->names;
                        $currentStream = $this->stream;

                        $bodyTokens[] = new Token(Token::EOF_TYPE, null, 0);
                        $bodyNode = $this->parse(
                            new TokenStream($bodyTokens),
                            array_merge($currentNames, $parameterNames)
                        );

                        $this->names = $currentNames;
                        $this->stream = $currentStream;
                        break;
                    }

                    $bodyTokens[] = $stream->current;
                    $stream->next();
                }
                $stream->expect(Token::PUNCTUATION_TYPE, '}', 'Anonymous function body must end with a curly bracket');
                $endPos = $stream->position();

                // update token stream
                $this->replacementNodes[$replacementNodeIndex] = new ArrowFuncNode($parameterNodes, $bodyNode);
function myFunction($a) {
    switch ($a) {
        case 'foo':
            $x = 1;
            break;

        case 'bar':
            $x = 2;
            break;
    }

    // $x is potentially undefined here.
    echo $x;
}
                $replacement = new Token(static::TOKEN_REPLACEMENT_TYPE, $replacementNodeIndex, $operatorCursor);
                $stream = $stream->splice($startPos, $endPos - $startPos, array($replacement));

                // keep parsing anonymous functions
                $stream->seek($startPos, SEEK_SET);
            }

            $stream->next();
        }
        $stream->rewind();

        return $stream;
    }

    public function parseExpression($precedence = 0)
    {
        $expr = $this->getPrimary();
        $token = $this->stream->current;
        while ($token->test(Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token->value]) && $this->binaryOperators[$token->value]['precedence'] >= $precedence) {
            $op = $this->binaryOperators[$token->value];
            $this->stream->next();

            $expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
            $expr = new BinaryNode($token->value, $expr, $expr1);

            $token = $this->stream->current;
        }

        if (0 === $precedence) {
            return $this->parseConditionalExpression($expr);
        }

        return $expr;
    }

    protected function getPrimary()
    {
        $token = $this->stream->current;

        if ($token->test(Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token->value])) {
            $operator = $this->unaryOperators[$token->value];
            $this->stream->next();
            $expr = $this->parseExpression($operator['precedence']);

            return $this->parsePostfixExpression(new UnaryNode($token->value, $expr));
        }

        if ($token->test(Token::PUNCTUATION_TYPE, '(')) {
            $this->stream->next();
            $expr = $this->parseExpression();
            $this->stream->expect(Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');

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

        return $this->parsePrimaryExpression();
    }

    protected function parseConditionalExpression($expr)
    {
        while ($this->stream->current->test(Token::PUNCTUATION_TYPE, '?')) {
            $this->stream->next();
            if (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ':')) {
                $expr2 = $this->parseExpression();
                if ($this->stream->current->test(Token::PUNCTUATION_TYPE, ':')) {
                    $this->stream->next();
                    $expr3 = $this->parseExpression();
                } else {
                    $expr3 = new ConstantNode(null);
                }
            } else {
                $this->stream->next();
                $expr2 = $expr;
                $expr3 = $this->parseExpression();
            }

            $expr = new ConditionalNode($expr, $expr2, $expr3);
        }

        return $expr;
    }

    public function parsePrimaryExpression()
    {
        $token = $this->stream->current;
        switch ($token->type) {
            case Token::NAME_TYPE:
                $this->stream->next();
                switch ($token->value) {
                    case 'true':
                    case 'TRUE':
                        return new ConstantNode(true);

                    case 'false':
                    case 'FALSE':
                        return new ConstantNode(false);

                    case 'null':
                    case 'NULL':
                        return new ConstantNode(null);

                    default:
                        if ('(' === $this->stream->current->value) {
                            if (false === isset($this->functions[$token->value])) {
                                throw new SyntaxError(sprintf('The function "%s" does not exist', $token->value), $token->cursor);
                            }

                            $node = new FunctionNode($token->value, $this->parseArguments());
                        } else {
                            if (!in_array($token->value, $this->names, true)) {
                                throw new SyntaxError(sprintf('Variable "%s" is not valid', $token->value), $token->cursor);
                            }

                            // is the name used in the compiled code different
                            // from the name used in the expression?
                            if (is_int($name = array_search($token->value, $this->names))) {
                                $name = $token->value;
                            }

                            $node = new NameNode($name);
                        }
                }
                break;

            case Token::NUMBER_TYPE:
            case Token::STRING_TYPE:
                $this->stream->next();

                return new ConstantNode($token->value);

            case static::TOKEN_REPLACEMENT_TYPE:
                $this->stream->next();

                return $this->replacementNodes[$token->value];

            default:
                if ($token->test(Token::PUNCTUATION_TYPE, '[')) {
                    $node = $this->parseArrayExpression();
                } elseif ($token->test(Token::PUNCTUATION_TYPE, '{')) {
                    $node = $this->parseHashExpression();
                } else {
                    throw new SyntaxError(sprintf('Unexpected token "%s" of value "%s"', $token->type, $token->value), $token->cursor);
                }
        }

        return $this->parsePostfixExpression($node);
    }

    public function parseArrayExpression()
    {
        $this->stream->expect(Token::PUNCTUATION_TYPE, '[', 'An array element was expected');

        $node = new ArrayNode();
        $first = true;
        while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ']')) {
            if (!$first) {

                $this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'An array element must be followed by a comma');

                // trailing ,?
                if ($this->stream->current->test(Token::PUNCTUATION_TYPE, ']')) {
                    break;
                }
            }
            $first = false;

            $node->addElement($this->parseExpression());
        }
        $this->stream->expect(Token::PUNCTUATION_TYPE, ']', 'An opened array is not properly closed');

        return $node;
    }

    public function parseHashExpression()
    {
        $this->stream->expect(Token::PUNCTUATION_TYPE, '{', 'A hash element was expected');

        $node = new ArrayNode();
        $first = true;
        while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
            if (!$first) {

                $this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'A hash value must be followed by a comma');

                // trailing ,?
                if ($this->stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
                    break;
                }
            }
            $first = false;

            // a hash key can be:

            //  * a number -- 12
            //  * a string -- 'a'
            //  * a name, which is equivalent to a string -- a
            //  * an expression, which must be enclosed in parentheses -- (1 + 2)
            if ($this->stream->current->test(Token::STRING_TYPE) || $this->stream->current->test(Token::NAME_TYPE) || $this->stream->current->test(Token::NUMBER_TYPE)) {
                $key = new ConstantNode($this->stream->current->value);
                $this->stream->next();
            } elseif ($this->stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
                $key = $this->parseExpression();
            } else {

                $current = $this->stream->current;

                throw new SyntaxError(sprintf('A hash key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s"', $current->type, $current->value), $current->cursor);
            }

            $this->stream->expect(Token::PUNCTUATION_TYPE, ':', 'A hash key must be followed by a colon (:)');
            $value = $this->parseExpression();

            $node->addElement($value, $key);
        }
        $this->stream->expect(Token::PUNCTUATION_TYPE, '}', 'An opened hash is not properly closed');

        return $node;
    }

    public function parsePostfixExpression($node)
    {
        $token = $this->stream->current;
        while ($token->type == Token::PUNCTUATION_TYPE) {
            if ('.' === $token->value) {
                $this->stream->next();
                $token = $this->stream->current;
                $this->stream->next();

                if (
                    $token->type !== Token::NAME_TYPE
                    &&
                    // Operators like "not" and "matches" are valid method or property names,

                    // In other words, besides NAME_TYPE, OPERATOR_TYPE could also be parsed as a property or method.
                    // This is because operators are processed by the lexer prior to names. So "not" in "foo.not()" or "matches" in "foo.matches" will be recognized as an operator first.
                    // But in fact, "not" and "matches" in such expressions shall be parsed as method or property names.

                    // And this ONLY works if the operator consists of valid characters for a property or method name.

                    // Other types, such as STRING_TYPE and NUMBER_TYPE, can't be parsed as property nor method names.

                    // As a result, if $token is NOT an operator OR $token->value is NOT a valid property or method name, an exception shall be thrown.
                    ($token->type !== Token::OPERATOR_TYPE || !preg_match('/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A', $token->value))
                ) {
                    throw new SyntaxError('Expected name', $token->cursor);
                }

                $arg = new NameNode($token->value);

                $arguments = new ArgumentsNode();
                if ($this->stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
                    $type = GetAttrNode::METHOD_CALL;
                    foreach ($this->parseArguments()->nodes as $n) {
                        $arguments->addElement($n);
                    }
                } else {
                    $type = GetAttrNode::PROPERTY_CALL;
                }

                $node = new GetAttrNode($node, $arg, $arguments, $type);
            } elseif ('[' === $token->value) {
                $this->stream->next();
                $arg = $this->parseExpression();
                $this->stream->expect(Token::PUNCTUATION_TYPE, ']');

                $node = new GetAttrNode($node, $arg, new ArgumentsNode(), GetAttrNode::ARRAY_CALL);
            } else {
                break;
            }

            $token = $this->stream->current;
        }

        return $node;
    }

    /**
     * Parses arguments.
     */
    public function parseArguments()
    {
        $args = array();
        $this->stream->expect(Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
        while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ')')) {
            if (!empty($args)) {
                $this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
            }

            $args[] = $this->parseExpression();
        }
        $this->stream->expect(Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');

        return new Node($args);
    }

    /**
     * @param array $functions
     */
    public function setFunctions(array $functions)
    {
        $this->functions = $functions;
    }
}


1			<?php
2
3			namespace uuf6429\ExpressionLanguage;
4
5			use uuf6429\ExpressionLanguage\Node\ArrowFuncNode;
6			use Symfony\Component\ExpressionLanguage\Node\ArgumentsNode;
7			use Symfony\Component\ExpressionLanguage\Node\ArrayNode;
8			use Symfony\Component\ExpressionLanguage\Node\BinaryNode;
9			use Symfony\Component\ExpressionLanguage\Node\ConditionalNode;
10			use Symfony\Component\ExpressionLanguage\Node\ConstantNode;
11			use Symfony\Component\ExpressionLanguage\Node\FunctionNode;
12			use Symfony\Component\ExpressionLanguage\Node\GetAttrNode;
13			use Symfony\Component\ExpressionLanguage\Node\NameNode;
14			use Symfony\Component\ExpressionLanguage\Node\Node;
15			use Symfony\Component\ExpressionLanguage\Node\UnaryNode;
16			use Symfony\Component\ExpressionLanguage\Token;
17			use Symfony\Component\ExpressionLanguage\SyntaxError;
18
19			class Parser
20			{
21			const OPERATOR_LEFT = 1;
22			const OPERATOR_RIGHT = 2;
23
24			const TOKEN_REPLACEMENT_TYPE = 'replacement';
25
26			/** @var TokenStream */
27			private $stream;
28
29			/** @var array */
30			private $unaryOperators;
31
32			/** @var array */
33			private $binaryOperators;
34
35			/** @var array */
36			private $functions;
37
38			/** @var string[] */
39			private $names;
40
41			/** @var Node[] */
42			private $replacementNodes;
43
44	27		public function __construct(array $functions)
45			{
46	27		$this->functions = $functions;
47
48	27		$this->unaryOperators = array(
49			'not' => array('precedence' => 50),
50			'!' => array('precedence' => 50),
51			'-' => array('precedence' => 500),
52			'+' => array('precedence' => 500),
53			);
54	27		$this->binaryOperators = array(
55	27		'->' => array('precedence' => 5, 'associativity' => self::OPERATOR_LEFT),
56	27		'or' => array('precedence' => 10, 'associativity' => self::OPERATOR_LEFT),
57	27		'\|\|' => array('precedence' => 10, 'associativity' => self::OPERATOR_LEFT),
58	27		'and' => array('precedence' => 15, 'associativity' => self::OPERATOR_LEFT),
59	27		'&&' => array('precedence' => 15, 'associativity' => self::OPERATOR_LEFT),
60	27		'\|' => array('precedence' => 16, 'associativity' => self::OPERATOR_LEFT),
61	27		'^' => array('precedence' => 17, 'associativity' => self::OPERATOR_LEFT),
62	27		'&' => array('precedence' => 18, 'associativity' => self::OPERATOR_LEFT),
63	27		'==' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
64	27		'===' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
65	27		'!=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
66	27		'!==' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
67	27		'<' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
68	27		'>' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
69	27		'>=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
70	27		'<=' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
71	27		'not in' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
72	27		'in' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
73	27		'matches' => array('precedence' => 20, 'associativity' => self::OPERATOR_LEFT),
74	27		'..' => array('precedence' => 25, 'associativity' => self::OPERATOR_LEFT),
75	27		'+' => array('precedence' => 30, 'associativity' => self::OPERATOR_LEFT),
76	27		'-' => array('precedence' => 30, 'associativity' => self::OPERATOR_LEFT),
77	27		'~' => array('precedence' => 40, 'associativity' => self::OPERATOR_LEFT),
78	27		'*' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
79	27		'/' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
80	27		'%' => array('precedence' => 60, 'associativity' => self::OPERATOR_LEFT),
81	27		'**' => array('precedence' => 200, 'associativity' => self::OPERATOR_RIGHT),
82			);
83
84	27		$this->replacementNodes = array();
85	27		}
86
87			/**
88			* Converts a token stream to a node tree.
89			*
90			* The valid names is an array where the values
91			* are the names that the user can use in an expression.
92			*
93			* If the variable name in the compiled PHP code must be
94			* different, define it as the key.
95			*
96			* For instance, ['this' => 'container'] means that the
97			* variable 'container' can be used in the expression
98			* but the compiled code will use 'this'.
99			*
100			* @param TokenStream $stream A token stream instance
101			* @param array $names An array of valid names
102			*
103			* @return Node A node tree
104			*
105			* @throws SyntaxError
106			*/
107	27		public function parse(TokenStream $stream, $names = array())
108			{
109	27		$this->names = $names;
110
111	27		$stream = $this->preParseArrowFuncs($stream);
112
113	27		$this->stream = $stream;
114	27		$node = $this->parseExpression();
115
116	21	View Code Duplication	if (!$stream->isEOF()) {
			0 ignored issues – show Duplication introduced 2016-10-30 17:22 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
117			throw new SyntaxError(
118			sprintf(
119			'Unexpected token "%s" of value "%s"',
120			$stream->current->type,
121			$stream->current->value
122			),
123			$stream->current->cursor
124			);
125			}
126
127	21		return $node;
128			}
129
130			/**
131			* Replaces all anonymous functions with placeholder tokens.
132			*
133			* @param TokenStream $stream
134			*
135			* @return TokenStream
136			*/
137	27		protected function preParseArrowFuncs(TokenStream $stream)
138			{
139	27		while (!$stream->isEOF()) {
140	27		if ($stream->current->test(Token::OPERATOR_TYPE, '->')) {
141	3		$operatorPos = $stream->position();
142	3		$operatorCursor = $stream->current->cursor;
143	3		$replacementNodeIndex = count($this->replacementNodes);
144	3		$this->replacementNodes[$replacementNodeIndex] = null;
145
146			// parse parameters
147	3		$parameterNames = array();
148	3		$parameterNodes = array();
149	3		$expectParam = true;
150	3		$stream->prev();
151	3		$stream->expectPrev(Token::PUNCTUATION_TYPE, ')', 'Parameter list must end with parenthesis');
152	3		while (!$stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
153	3		if ($expectParam) {
154	3		$stream->current->test(Token::NAME_TYPE);
155	3		array_unshift($parameterNames, $stream->current->value);
156	3		array_unshift($parameterNodes, new NameNode($stream->current->value));
157	3		$stream->prev();
158			} else {
159	2		$stream->expectPrev(Token::PUNCTUATION_TYPE, ',', 'Parameters must be separated by a comma');
160			}
161	3		$expectParam = !$expectParam;
162			}
163	3		$startPos = $stream->position();
164
165			// parse body
166	3		$stream->seek($operatorPos, SEEK_SET);
167	3		$stream->next();
168	3		$stream->expect(Token::PUNCTUATION_TYPE, '{', 'Anonymous function body must start with a curly bracket');
169	3		$bodyTokens = array();
170	3		$openingBracketCount = 1;
171	3		while ($openingBracketCount != 0) {
172	3		if ($stream->current->test(Token::PUNCTUATION_TYPE, '{')) {
173	1		++$openingBracketCount;
174			}
175
176	3		if ($stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
177	3		--$openingBracketCount;
178			}
179
180	3		if (!$openingBracketCount) {
181	3		$currentNames = $this->names;
182	3		$currentStream = $this->stream;
183
184	3		$bodyTokens[] = new Token(Token::EOF_TYPE, null, 0);
185	3		$bodyNode = $this->parse(
186	3		new TokenStream($bodyTokens),
187			array_merge($currentNames, $parameterNames)
188			);
189
190	3		$this->names = $currentNames;
191	3		$this->stream = $currentStream;
192	3		break;
193			}
194
195	3		$bodyTokens[] = $stream->current;
196	3		$stream->next();
197			}
198	3		$stream->expect(Token::PUNCTUATION_TYPE, '}', 'Anonymous function body must end with a curly bracket');
199	3		$endPos = $stream->position();
200
201			// update token stream
202	3		$this->replacementNodes[$replacementNodeIndex] = new ArrowFuncNode($parameterNodes, $bodyNode);
			0 ignored issues – show Bug introduced 2016-10-30 05:23 UTC by Report Bug Copy Issue Report The variable `$bodyNode` does not seem to be defined for all execution paths leading up to this point. If you define a variable conditionally, it can happen that it is not defined for all execution paths. Let’s take a look at an example: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } // $x is potentially undefined here. echo $x; } In the above example, the variable `$x` is defined if you pass “foo” or “bar” as argument for `$a`. However, since the `switch` statement has no default case statement, if you pass any other value, the variable `$x` would be undefined. Available Fixes Check for existence of the variable explicitly: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } if (isset($x)) { // Make sure it's always set. echo $x; } } Define a default value for the variable: function myFunction($a) { $x = ''; // Set a default which gets overridden for certain paths. switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; } echo $x; } Add a value for the missing path: function myFunction($a) { switch ($a) { case 'foo': $x = 1; break; case 'bar': $x = 2; break; // We add support for the missing case. default: $x = ''; break; } echo $x; } Loading history...
203	3		$replacement = new Token(static::TOKEN_REPLACEMENT_TYPE, $replacementNodeIndex, $operatorCursor);
204	3		$stream = $stream->splice($startPos, $endPos - $startPos, array($replacement));
205
206			// keep parsing anonymous functions
207	3		$stream->seek($startPos, SEEK_SET);
208			}
209
210	27		$stream->next();
211			}
212	27		$stream->rewind();
213
214	27		return $stream;
215			}
216
217	27		public function parseExpression($precedence = 0)
218			{
219	27		$expr = $this->getPrimary();
220	21		$token = $this->stream->current;
221	21		while ($token->test(Token::OPERATOR_TYPE) && isset($this->binaryOperators[$token->value]) && $this->binaryOperators[$token->value]['precedence'] >= $precedence) {
222	6		$op = $this->binaryOperators[$token->value];
223	6		$this->stream->next();
224
225	6		$expr1 = $this->parseExpression(self::OPERATOR_LEFT === $op['associativity'] ? $op['precedence'] + 1 : $op['precedence']);
226	6		$expr = new BinaryNode($token->value, $expr, $expr1);
227
228	6		$token = $this->stream->current;
229			}
230
231	21		if (0 === $precedence) {
232	21		return $this->parseConditionalExpression($expr);
233			}
234
235	7		return $expr;
236			}
237
238	27		protected function getPrimary()
239			{
240	27		$token = $this->stream->current;
241
242	27		if ($token->test(Token::OPERATOR_TYPE) && isset($this->unaryOperators[$token->value])) {
243	1		$operator = $this->unaryOperators[$token->value];
244	1		$this->stream->next();
245	1		$expr = $this->parseExpression($operator['precedence']);
246
247	1		return $this->parsePostfixExpression(new UnaryNode($token->value, $expr));
248			}
249
250	27		if ($token->test(Token::PUNCTUATION_TYPE, '(')) {
251	1		$this->stream->next();
252	1		$expr = $this->parseExpression();
253	1		$this->stream->expect(Token::PUNCTUATION_TYPE, ')', 'An opened parenthesis is not properly closed');
254
255	1		return $this->parsePostfixExpression($expr);
256			}
257
258	27		return $this->parsePrimaryExpression();
259			}
260
261	21		protected function parseConditionalExpression($expr)
262			{
263	21		while ($this->stream->current->test(Token::PUNCTUATION_TYPE, '?')) {
264	1		$this->stream->next();
265	1		if (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ':')) {
266	1		$expr2 = $this->parseExpression();
267	1		if ($this->stream->current->test(Token::PUNCTUATION_TYPE, ':')) {
268	1		$this->stream->next();
269	1		$expr3 = $this->parseExpression();
270			} else {
271	1		$expr3 = new ConstantNode(null);
272			}
273			} else {
274			$this->stream->next();
275			$expr2 = $expr;
276			$expr3 = $this->parseExpression();
277			}
278
279	1		$expr = new ConditionalNode($expr, $expr2, $expr3);
280			}
281
282	21		return $expr;
283			}
284
285	27		public function parsePrimaryExpression()
286			{
287	27		$token = $this->stream->current;
288	27		switch ($token->type) {
289	27		case Token::NAME_TYPE:
290	21		$this->stream->next();
291	21		switch ($token->value) {
292	21		case 'true':
293	20		case 'TRUE':
294	3		return new ConstantNode(true);
295
296	20		case 'false':
297	18		case 'FALSE':
298	2		return new ConstantNode(false);
299
300	18		case 'null':
301	17		case 'NULL':
302	1		return new ConstantNode(null);
303
304			default:
305	17		if ('(' === $this->stream->current->value) {
306	2		if (false === isset($this->functions[$token->value])) {
307			throw new SyntaxError(sprintf('The function "%s" does not exist', $token->value), $token->cursor);
308			}
309
310	2		$node = new FunctionNode($token->value, $this->parseArguments());
311			} else {
312	17		if (!in_array($token->value, $this->names, true)) {
313	2		throw new SyntaxError(sprintf('Variable "%s" is not valid', $token->value), $token->cursor);
314			}
315
316			// is the name used in the compiled code different
317			// from the name used in the expression?
318	15		if (is_int($name = array_search($token->value, $this->names))) {
319	14		$name = $token->value;
320			}
321
322	15		$node = new NameNode($name);
323			}
324			}
325	15		break;
326
327	12		case Token::NUMBER_TYPE:
328	6		case Token::STRING_TYPE:
329	10		$this->stream->next();
330
331	10		return new ConstantNode($token->value);
332
333	3		case static::TOKEN_REPLACEMENT_TYPE:
334	3		$this->stream->next();
335
336	3		return $this->replacementNodes[$token->value];
337
338			default:
339			if ($token->test(Token::PUNCTUATION_TYPE, '[')) {
340			$node = $this->parseArrayExpression();
341			} elseif ($token->test(Token::PUNCTUATION_TYPE, '{')) {
342			$node = $this->parseHashExpression();
343			} else {
344			throw new SyntaxError(sprintf('Unexpected token "%s" of value "%s"', $token->type, $token->value), $token->cursor);
345			}
346			}
347
348	15		return $this->parsePostfixExpression($node);
349			}
350
351			public function parseArrayExpression()
352			{
353			$this->stream->expect(Token::PUNCTUATION_TYPE, '[', 'An array element was expected');
354
355			$node = new ArrayNode();
356			$first = true;
357			while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ']')) {
358		View Code Duplication	if (!$first) {
			0 ignored issues – show Duplication introduced 2016-10-30 17:22 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
359			$this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'An array element must be followed by a comma');
360
361			// trailing ,?
362			if ($this->stream->current->test(Token::PUNCTUATION_TYPE, ']')) {
363			break;
364			}
365			}
366			$first = false;
367
368			$node->addElement($this->parseExpression());
369			}
370			$this->stream->expect(Token::PUNCTUATION_TYPE, ']', 'An opened array is not properly closed');
371
372			return $node;
373			}
374
375			public function parseHashExpression()
376			{
377			$this->stream->expect(Token::PUNCTUATION_TYPE, '{', 'A hash element was expected');
378
379			$node = new ArrayNode();
380			$first = true;
381			while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
382		View Code Duplication	if (!$first) {
			0 ignored issues – show Duplication introduced 2016-10-30 17:22 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
383			$this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'A hash value must be followed by a comma');
384
385			// trailing ,?
386			if ($this->stream->current->test(Token::PUNCTUATION_TYPE, '}')) {
387			break;
388			}
389			}
390			$first = false;
391
392			// a hash key can be:
393
394			// * a number -- 12
395			// * a string -- 'a'
396			// * a name, which is equivalent to a string -- a
397			// * an expression, which must be enclosed in parentheses -- (1 + 2)
398			if ($this->stream->current->test(Token::STRING_TYPE) \|\| $this->stream->current->test(Token::NAME_TYPE) \|\| $this->stream->current->test(Token::NUMBER_TYPE)) {
399			$key = new ConstantNode($this->stream->current->value);
400			$this->stream->next();
401			} elseif ($this->stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
402			$key = $this->parseExpression();
403		View Code Duplication	} else {
			0 ignored issues – show Duplication introduced 2016-10-30 17:22 UTC by Report Bug Copy Issue Report This code seems to be duplicated across your project. Duplicated code is one of the most pungent code smells. If you need to duplicate the same code in three or more different places, we strongly encourage you to look into extracting the code into a single class or operation. You can also find more detailed suggestions in the “Code” section of your repository. Loading history...
404			$current = $this->stream->current;
405
406			throw new SyntaxError(sprintf('A hash key must be a quoted string, a number, a name, or an expression enclosed in parentheses (unexpected token "%s" of value "%s"', $current->type, $current->value), $current->cursor);
407			}
408
409			$this->stream->expect(Token::PUNCTUATION_TYPE, ':', 'A hash key must be followed by a colon (:)');
410			$value = $this->parseExpression();
411
412			$node->addElement($value, $key);
413			}
414			$this->stream->expect(Token::PUNCTUATION_TYPE, '}', 'An opened hash is not properly closed');
415
416			return $node;
417			}
418
419	17		public function parsePostfixExpression($node)
420			{
421	17		$token = $this->stream->current;
422	17		while ($token->type == Token::PUNCTUATION_TYPE) {
423	12		if ('.' === $token->value) {
424	9		$this->stream->next();
425	9		$token = $this->stream->current;
426	9		$this->stream->next();
427
428			if (
429	9		$token->type !== Token::NAME_TYPE
430			&&
431			// Operators like "not" and "matches" are valid method or property names,
432
433			// In other words, besides NAME_TYPE, OPERATOR_TYPE could also be parsed as a property or method.
434			// This is because operators are processed by the lexer prior to names. So "not" in "foo.not()" or "matches" in "foo.matches" will be recognized as an operator first.
435			// But in fact, "not" and "matches" in such expressions shall be parsed as method or property names.
436
437			// And this ONLY works if the operator consists of valid characters for a property or method name.
438
439			// Other types, such as STRING_TYPE and NUMBER_TYPE, can't be parsed as property nor method names.
440
441			// As a result, if $token is NOT an operator OR $token->value is NOT a valid property or method name, an exception shall be thrown.
442	9		($token->type !== Token::OPERATOR_TYPE \|\| !preg_match('/[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*/A', $token->value))
443			) {
444	4		throw new SyntaxError('Expected name', $token->cursor);
445			}
446
447	5		$arg = new NameNode($token->value);
448
449	5		$arguments = new ArgumentsNode();
450	5		if ($this->stream->current->test(Token::PUNCTUATION_TYPE, '(')) {
451	4		$type = GetAttrNode::METHOD_CALL;
452	4		foreach ($this->parseArguments()->nodes as $n) {
453	4		$arguments->addElement($n);
454			}
455			} else {
456	2		$type = GetAttrNode::PROPERTY_CALL;
457			}
458
459	5		$node = new GetAttrNode($node, $arg, $arguments, $type);
460	4		} elseif ('[' === $token->value) {
461	2		$this->stream->next();
462	2		$arg = $this->parseExpression();
463	2		$this->stream->expect(Token::PUNCTUATION_TYPE, ']');
464
465	2		$node = new GetAttrNode($node, $arg, new ArgumentsNode(), GetAttrNode::ARRAY_CALL);
466			} else {
467	2		break;
468			}
469
470	6		$token = $this->stream->current;
471			}
472
473	13		return $node;
474			}
475
476			/**
477			* Parses arguments.
478			*/
479	6		public function parseArguments()
480			{
481	6		$args = array();
482	6		$this->stream->expect(Token::PUNCTUATION_TYPE, '(', 'A list of arguments must begin with an opening parenthesis');
483	6		while (!$this->stream->current->test(Token::PUNCTUATION_TYPE, ')')) {
484	3		if (!empty($args)) {
485	3		$this->stream->expect(Token::PUNCTUATION_TYPE, ',', 'Arguments must be separated by a comma');
486			}
487
488	3		$args[] = $this->parseExpression();
489			}
490	6		$this->stream->expect(Token::PUNCTUATION_TYPE, ')', 'A list of arguments must be closed by a parenthesis');
491
492	6		return new Node($args);
493			}
494
495			/**
496			* @param array $functions
497			*/
498	1		public function setFunctions(array $functions)
499			{
500	1		$this->functions = $functions;
501	1		}
502			}
503

uuf6429 / expression-language-arrowfunc

Push — master ( 8cc02b...5173bc )

Parser::parseExpression() B

Complexity

Size

Duplication

Code Coverage

Importance

Available Fixes

Duplication Side-by-Side

Filter issues like