Parser::parse() - Code Metrics - Inspection of "Better structure" - koesie10/LuaSerializer - Measure and Improve Code Quality continuously with Scrutinizer

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Push — master ( 0f10a6...8f1e95 )

by Koen

created 2015-12-22 11:51 UTC

Parser::parse() C

↳ Parent: Parser

Complexity

Conditions	8
Paths	7

Size

Total Lines	23
Code Lines	16

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	13
CRAP Score	8.8338

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	23
ccs	13
cts	17
cp	0.7647
rs	6.1404
cc	8
eloc	16
nc	7
nop	0
crap	8.8338

<?php

namespace Vlaswinkel\Lua;

use Vlaswinkel\Lua\AST\ASTNode;
use Vlaswinkel\Lua\AST\NilASTNode;
use Vlaswinkel\Lua\AST\NumberASTNode;
use Vlaswinkel\Lua\AST\StringASTNode;
use Vlaswinkel\Lua\AST\TableASTNode;
use Vlaswinkel\Lua\AST\TableEntryASTNode;

/**
 * Class Parser
 *
 * @see     http://lisperator.net/pltut/parser/the-parser
 *
 * @author  Koen Vlaswinkel <[email protected]>
 * @package Vlaswinkel\Lua
 */
class Parser {
    /**
     * @var TokenStream
     */
    private $input;

    /**
     * Parser constructor.
     *
     * @param TokenStream $input
     */
    public function __construct(TokenStream $input) {
        $this->input = $input;
    }

    /**
     * @return ASTNode
     *
     * @throws ParseException
     */
    public function parse() {
        if ($this->isPunctuation('{')) {
            return $this->parseTable();
        }
        if ($this->isPunctuation('[')) {
            return $this->parseTableKey();
        }
        $token = $this->input->next();
        if ($token->getType() == Token::TYPE_NUMBER) {
            return new NumberASTNode($token->getValue());
        }
        if ($token->getType() == Token::TYPE_STRING || $token->getType() == Token::TYPE_IDENTIFIER) {
            return new StringASTNode($token->getValue());
        }
        if ($token->getType() == Token::TYPE_KEYWORD) {
            if ($token->getValue() === 'nil') {
                return new NilASTNode();
            } else {
                $this->input->error('Unexpected keyword: ' . $token->getValue());
            }
        }
        $this->unexpected();
    }

    /**
     * @return TableASTNode
     */
    protected function parseTable() {
        return new TableASTNode(
            $this->delimited(
                '{',
                '}',
                ',',
                [$this, 'parseTableEntry']
            )
        );
    }

    /**
     * @return TableEntryASTNode
     */
    protected function parseTableEntry() {
        $token = $this->parse();
        if ($this->isPunctuation('=')) {
            $this->skipPunctuation('=');
            $value = $this->parse();
            return new TableEntryASTNode(
                $value,
/** @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);
    }
}
                $token
            );
        }
        return new TableEntryASTNode($token);
/** @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);
    }
}
    }

    /**
     * @return ASTNode
     */
    protected function parseTableKey() {
        $this->skipPunctuation('[');
        $token = $this->parse();
        $this->skipPunctuation(']');
        return $token;
    }

    /**
     * @param string   $start
     * @param string   $stop
     * @param string   $separator
     * @param callable $parser
     *
     * @return array
     */
    protected function delimited($start, $stop, $separator, callable $parser) {
        $a     = [];
        $first = true;
        $this->skipPunctuation($start);
        while (!$this->input->eof()) {
            if ($this->isPunctuation($stop)) {
                break;
            }
            if ($first) {
                $first = false;
            } else {
                $this->skipPunctuation($separator);
            }
            if ($this->isPunctuation($stop)) {
                break;
            }
            $a[] = $parser();
        }
        $this->skipPunctuation($stop);
        return $a;
    }

    /**
     * @param string|null $char
     *
     * @return bool
     */
    protected function isPunctuation($char = null) {
        $token = $this->input->peek();
        return $token && $token->getType() == Token::TYPE_PUNCTUATION && ($char === null || $token->getValue(
            ) == $char);
    }

    /**
     * @param string|null $char
     *
     * @throws ParseException
     */
    protected function skipPunctuation($char = null) {
        if ($this->isPunctuation($char)) {
            $this->input->next();
        } else {
            $this->input->error('Expecting punctuation: "' . $char . '"');
        }
    }

    /**
     * @throws ParseException
     */
    protected function unexpected() {
        $this->input->error('Unexpected token: ' . json_encode($this->input->peek()));
    }
}

1		<?php
2
3		namespace Vlaswinkel\Lua;
4
5		use Vlaswinkel\Lua\AST\ASTNode;
6		use Vlaswinkel\Lua\AST\NilASTNode;
7		use Vlaswinkel\Lua\AST\NumberASTNode;
8		use Vlaswinkel\Lua\AST\StringASTNode;
9		use Vlaswinkel\Lua\AST\TableASTNode;
10		use Vlaswinkel\Lua\AST\TableEntryASTNode;
11
12		/**
13		* Class Parser
14		*
15		* @see http://lisperator.net/pltut/parser/the-parser
16		*
17		* @author Koen Vlaswinkel <[email protected]>
18		* @package Vlaswinkel\Lua
19		*/
20		class Parser {
21		/**
22		* @var TokenStream
23		*/
24		private $input;
25
26		/**
27		* Parser constructor.
28		*
29		* @param TokenStream $input
30		*/
31	13	public function __construct(TokenStream $input) {
32	13	$this->input = $input;
33	13	}
34
35		/**
36		* @return ASTNode
37		*
38		* @throws ParseException
39		*/
40	13	public function parse() {
41	13	if ($this->isPunctuation('{')) {
42	6	return $this->parseTable();
43		}
44	12	if ($this->isPunctuation('[')) {
45	2	return $this->parseTableKey();
46		}
47	12	$token = $this->input->next();
48	12	if ($token->getType() == Token::TYPE_NUMBER) {
49	4	return new NumberASTNode($token->getValue());
50		}
51	10	if ($token->getType() == Token::TYPE_STRING \|\| $token->getType() == Token::TYPE_IDENTIFIER) {
52	8	return new StringASTNode($token->getValue());
53		}
54	2	if ($token->getType() == Token::TYPE_KEYWORD) {
55	2	if ($token->getValue() === 'nil') {
56	2	return new NilASTNode();
57		} else {
58		$this->input->error('Unexpected keyword: ' . $token->getValue());
59		}
60		}
61		$this->unexpected();
62		}
63
64		/**
65		* @return TableASTNode
66		*/
67	6	protected function parseTable() {
68	6	return new TableASTNode(
69	6	$this->delimited(
70	6	'{',
71	6	'}',
72	6	',',
73	6	[$this, 'parseTableEntry']
74	6	)
75	5	);
76		}
77
78		/**
79		* @return TableEntryASTNode
80		*/
81	5	protected function parseTableEntry() {
82	5	$token = $this->parse();
83	5	if ($this->isPunctuation('=')) {
84	4	$this->skipPunctuation('=');
85	4	$value = $this->parse();
86	4	return new TableEntryASTNode(
87	4	$value,
		0 ignored issues – show Bug introduced 2015-12-22 12:03 UTC by Report Bug Copy Issue Report It seems like `$value` defined by `$this->parse()` on line `85` 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...
88		$token
89	4	);
90		}
91	3	return new TableEntryASTNode($token);
		0 ignored issues – show Bug introduced 2015-12-22 12:03 UTC by Report Bug Copy Issue Report It seems like `$token` defined by `$this->parse()` on line `82` 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...
92		}
93
94		/**
95		* @return ASTNode
96		*/
97	2	protected function parseTableKey() {
98	2	$this->skipPunctuation('[');
99	2	$token = $this->parse();
100	2	$this->skipPunctuation(']');
101	2	return $token;
102		}
103
104		/**
105		* @param string $start
106		* @param string $stop
107		* @param string $separator
108		* @param callable $parser
109		*
110		* @return array
111		*/
112	6	protected function delimited($start, $stop, $separator, callable $parser) {
113	6	$a = [];
114	6	$first = true;
115	6	$this->skipPunctuation($start);
116	6	while (!$this->input->eof()) {
117	6	if ($this->isPunctuation($stop)) {
118	5	break;
119		}
120	5	if ($first) {
121	5	$first = false;
122	5	} else {
123	2	$this->skipPunctuation($separator);
124		}
125	5	if ($this->isPunctuation($stop)) {
126		break;
127		}
128	5	$a[] = $parser();
129	5	}
130	5	$this->skipPunctuation($stop);
131	5	return $a;
132		}
133
134		/**
135		* @param string\|null $char
136		*
137		* @return bool
138		*/
139	13	protected function isPunctuation($char = null) {
140	13	$token = $this->input->peek();
141	13	return $token && $token->getType() == Token::TYPE_PUNCTUATION && ($char === null \|\| $token->getValue(
142	13	) == $char);
143		}
144
145		/**
146		* @param string\|null $char
147		*
148		* @throws ParseException
149		*/
150	7	protected function skipPunctuation($char = null) {
151	7	if ($this->isPunctuation($char)) {
152	7	$this->input->next();
153	7	} else {
154	1	$this->input->error('Expecting punctuation: "' . $char . '"');
155		}
156	7	}
157
158		/**
159		* @throws ParseException
160		*/
161		protected function unexpected() {
162		$this->input->error('Unexpected token: ' . json_encode($this->input->peek()));
163		}
164		}

koesie10 / LuaSerializer

Push — master ( 0f10a6...8f1e95 )

Parser::parse() C

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