Parser::delimited()   B
last analyzed

Complexity

Conditions 5
Paths 4

Size

Total Lines 21
Code Lines 16

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 17
CRAP Score 5

Importance

Changes 0
Metric Value
dl 0
loc 21
c 0
b 0
f 0
ccs 17
cts 17
cp 1
rs 8.7624
nc 4
cc 5
eloc 16
nop 4
crap 5
1
<?php
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namespace Vlaswinkel\Lua;
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use Vlaswinkel\Lua\AST\ASTNode;
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use Vlaswinkel\Lua\AST\NilASTNode;
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use Vlaswinkel\Lua\AST\NumberASTNode;
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use Vlaswinkel\Lua\AST\StringASTNode;
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use Vlaswinkel\Lua\AST\TableASTNode;
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use Vlaswinkel\Lua\AST\TableEntryASTNode;
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/**
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 * Class Parser
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 *
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 * @see     http://lisperator.net/pltut/parser/the-parser
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 *
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 * @author  Koen Vlaswinkel <[email protected]>
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 * @package Vlaswinkel\Lua
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 */
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class Parser {
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    /**
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     * @var TokenStream
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     */
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    private $input;
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    /**
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     * Parser constructor.
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     *
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     * @param TokenStream $input
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     */
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    public function __construct(TokenStream $input) {
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        $this->input = $input;
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    }
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    /**
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     * @return ASTNode
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     *
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     * @throws ParseException
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     */
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    public function parse() {
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        $result = $this->parseInternal();
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43 22
        if (!$this->input->eof()) {
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            if ($result instanceof StringASTNode && $this->isPunctuation('=')) {
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                $this->skipPunctuation('=');
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                $value = $this->parseInternal();
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                return new TableASTNode([new TableEntryASTNode($value, $result)]);
0 ignored issues
show
Bug introduced by
It seems like $value defined by $this->parseInternal() on line 46 can be null; however, Vlaswinkel\Lua\AST\Table...yASTNode::__construct() does not accept null, maybe add an additional type check?

Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code:

/** @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);
    }
}
Loading history...
49
            }
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            $this->input->error('Parser has finished parsing, but end of file was not reached. Next character is ' . $this->input->peek()->getValue());
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        }
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54 20
        return $result;
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    }
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    /**
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     * @return ASTNode
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     *
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     * @throws ParseException
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     */
62 24
    protected function parseInternal() {
63 24
        if ($this->isPunctuation('{')) {
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            return $this->parseTable();
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        }
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        if ($this->isPunctuation('[')) {
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            return $this->parseTableKey();
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        }
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        $token = $this->input->next();
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        if ($token->getType() == Token::TYPE_NUMBER) {
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            return new NumberASTNode($token->getValue());
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        }
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        if ($token->getType() == Token::TYPE_STRING || $token->getType() == Token::TYPE_IDENTIFIER) {
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            return new StringASTNode($token->getValue());
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        }
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        if ($token->getType() == Token::TYPE_KEYWORD) {
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            if ($token->getValue() === 'nil') {
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                return new NilASTNode();
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            } else {
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                $this->input->error('Unexpected keyword: ' . $token->getValue());
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            }
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        }
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        $this->unexpected();
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    }
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    /**
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     * @return TableASTNode
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     */
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    protected function parseTable() {
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        return new TableASTNode(
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            $this->delimited(
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                '{',
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                '}',
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                ',',
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                [$this, 'parseTableEntry']
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            )
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        );
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    }
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    /**
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     * @return TableEntryASTNode
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     */
103 12
    protected function parseTableEntry() {
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        $token = $this->parseInternal();
105 12
        if ($this->isPunctuation('=')) {
106 11
            $this->skipPunctuation('=');
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            $value = $this->parseInternal();
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            return new TableEntryASTNode(
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                $value,
0 ignored issues
show
Bug introduced by
It seems like $value defined by $this->parseInternal() on line 107 can be null; however, Vlaswinkel\Lua\AST\Table...yASTNode::__construct() does not accept null, maybe add an additional type check?

Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code:

/** @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);
    }
}
Loading history...
110
                $token
111 11
            );
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        }
113 5
        return new TableEntryASTNode($token);
0 ignored issues
show
Bug introduced by
It seems like $token defined by $this->parseInternal() on line 104 can be null; however, Vlaswinkel\Lua\AST\Table...yASTNode::__construct() does not accept null, maybe add an additional type check?

Unless you are absolutely sure that the expression can never be null because of other conditions, we strongly recommend to add an additional type check to your code:

/** @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);
    }
}
Loading history...
114
    }
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    /**
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     * @return ASTNode
0 ignored issues
show
Documentation introduced by
Should the return type not be ASTNode|null?

This check compares the return type specified in the @return annotation of a function or method doc comment with the types returned by the function and raises an issue if they mismatch.

Loading history...
118
     */
119 4
    protected function parseTableKey() {
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        $this->skipPunctuation('[');
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        $token = $this->parseInternal();
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        $this->skipPunctuation(']');
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        return $token;
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    }
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    /**
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     * @param string   $start
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     * @param string   $stop
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     * @param string   $separator
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     * @param callable $parser
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     *
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     * @return array
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     */
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    protected function delimited($start, $stop, $separator, callable $parser) {
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        $a     = [];
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        $first = true;
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        $this->skipPunctuation($start);
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        while (!$this->input->eof()) {
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            if ($this->isPunctuation($stop)) {
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                break;
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            }
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            if ($first) {
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                $first = false;
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            } else {
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                $this->skipPunctuation($separator);
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            }
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            if ($this->isPunctuation($stop)) {
148 2
                break;
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            }
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            $a[] = $parser();
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        }
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        $this->skipPunctuation($stop);
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        return $a;
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    }
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    /**
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     * @param string|null $char
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     *
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     * @return bool
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     */
161 24
    protected function isPunctuation($char = null) {
162 24
        $token = $this->input->peek();
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        return $token && $token->getType() == Token::TYPE_PUNCTUATION && ($char === null || $token->getValue(
164 24
            ) == $char);
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    }
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    /**
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     * @param string|null $char
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     *
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     * @throws ParseException
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     */
172 14
    protected function skipPunctuation($char = null) {
173 14
        if ($this->isPunctuation($char)) {
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            $this->input->next();
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        } else {
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            $this->input->error('Expecting punctuation: "' . $char . '"');
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        }
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    }
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    /**
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     * @throws ParseException
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     */
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    protected function unexpected() {
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        $this->input->error('Unexpected token: ' . json_encode($this->input->peek()));
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    }
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}