RuleParser::add_symbols_for_rules_to() - Code Metrics - Inspection of "some refactoring of RuleParser" - lechimp-p/dicto.php - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 3d6cb8...b93a87 )

by Richard

created 2016-09-03 20:08 UTC

RuleParser::add_symbols_for_rules_to() A

↳ Parent: RuleParser

Complexity

Conditions	4
Paths	1

Size

Total Lines	18
Code Lines	12

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	12
CRAP Score	4.0072

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
c	2
b	0
f	0
dl	0
loc	18
ccs	12
cts	13
cp	0.9231
rs	9.2
cc	4
eloc	12
nc	1
nop	1
crap	4.0072

<?php
/******************************************************************************
 * An implementation of dicto (scg.unibe.ch/dicto) in and for PHP.
 *
 * Copyright (c) 2016 Richard Klees <[email protected]>
 * 
 * This software is licensed under The MIT License. You should have received
 * a copy of the license along with the code.
 */

namespace Lechimp\Dicto\Definition;

use Lechimp\Dicto\Rules\Ruleset;
use Lechimp\Dicto\Variables as V;
use Lechimp\Dicto\Rules as R;

/**
 * Parser for Rulesets.
 */
class RuleParser extends Parser implements ArgumentParser {
    const ASSIGNMENT_RE = "(\w+)\s*=\s*";
    const STRING_RE = "[\"]((([\\\\][\"])|[^\"])+)[\"]";
    const RULE_MODE_RE = "must|can(not)?";

    /**
     * @var V\Variable[]
     */
    protected $predefined_variables;

    /**
     * @var R\Schema[]
     */
    protected $schemas;

    /**
     * @var R\Property[]
     */
    protected $properties;

    /**
     * @var V\Variable[]
     */
    protected $variables = array();

    /**
     * @var R\Rule[]
     */
    protected $rules = array();

    /**
     * TODO: make arrays passed by reference as they get copied anyway.
     *
     * @param   V\Variable[]    $predefined_variables
     * @param   R\Schema[]      $schemas
     * @param   V\Property[]    $properties
     */
    public function __construct( array $predefined_variables
                               , array $schemas
                               , array $properties) {
        $this->predefined_variables = array_map(function(V\Variable $v) {
            return $v;
        }, $predefined_variables);
        $this->schemas = array_map(function(R\Schema $s) {
            return $s;
        }, $schemas);
        $this->properties = array_map(function(V\Property $p) {
            return $p;
        }, $properties);
        parent::__construct();
    }

    // Definition of symbols in the parser

    /**
     * @inheritdocs
     */
    protected function add_symbols_to(SymbolTable $table) {
        $this->add_symbols_for_variables_to($table);

        $this->add_symbols_for_rules_to($table);

        // Strings
        $table->symbol(self::STRING_RE);

        // Assignment 
        $table->symbol(self::ASSIGNMENT_RE);

        // Names
        $table->literal("\w+", function (array &$matches) {
                return $this->get_variable($matches[0]);
            });

        // End of statement
        $table->symbol("\n");
    }

    /**
     * @param   SymbolTable
     * @return  null
     */
    protected function add_symbols_for_variables_to(SymbolTable $table) {
        // Any
        $table->operator("{")
            ->null_denotation_is(function() {
                $arr = array();
                while(true) {
                    $arr[] = $this->variable(0);
                    if ($this->is_current_token_operator("}")) {
                        $this->advance_operator("}");
                        return new V\Any($arr);
                    }
                    $this->advance_operator(",");
                }
            });
        $table->operator("}");
        $table->operator(",");

        // Except
        $table->symbol("except", 10)
            ->left_denotation_is(function($left, array &$matches) {

                if (!($left instanceof V\Variable)) {
                    throw new ParserException
                        ("Expected a variable at the left of except.");
                }
                $right = $this->variable(10);
                return new V\Except($left, $right);
            });

        $this->add_symbols_for_properties_to($table, $this->properties);
    }

    /**
     * @param   SymbolTable     $table
     * @param   V\Property[]    $properties
     * @return  null
     */
    protected function add_symbols_for_properties_to(SymbolTable $table, array &$properties) {
        foreach ($properties as $property) {
            $table->symbol($property->parse_as().":", 20)
                ->left_denotation_is(function($left) use ($property) {
                    if (!($left instanceof V\Variable)) {
                        throw new ParserException
                            ("Expected a variable at the left of \"with name:\".");
                    }
                    $this->is_start_of_rule_arguments = true;
                    $arguments = $property->fetch_arguments($this);
                    assert('is_array($arguments)');
                    return new V\WithProperty($left, $property, $arguments);
                });
        }
    }

    /**
     * @param   SymbolTable
     * @return  null
     */
    protected function add_symbols_for_rules_to(SymbolTable $table) {
        // Rules
        $table->symbol("only");
        $table->symbol(self::RULE_MODE_RE, 0)
            ->null_denotation_is(function (array &$matches) {
                if ($matches[0] == "can") {
                    return R\Rule::MODE_ONLY_CAN;
                }
                if ($matches[0] == "must") {
                    return R\Rule::MODE_MUST;
                }
                if ($matches[0] == "cannot") {
                    return R\Rule::MODE_CANNOT;
                }
                throw new \LogicException("Unexpected \"".$matches[0]."\".");
            });
        $this->add_symbols_for_schemas_to($table, $this->schemas);
    }

    /**
     * @param   SymbolTable     $table
     * @param   R\Schema[]    $schemas
     * @return  null
     */
    protected function add_symbols_for_schemas_to(SymbolTable $table, array &$schemas) {
        foreach ($schemas as $schema) {
            $table->symbol($schema->name())
                ->null_denotation_is(function(array &$_) use ($schema) {

                    return $schema;
                });
        }
    }

    // IMPLEMENTATION OF Parser

    /**
     * @return  Ruleset
     */
    public function parse($source) {
        $this->variables = array();
        $this->rules = array();
        $this->add_predefined_variables();
        return parent::parse($source);
    }

    /**
     * Parses the top level statements in the rules file.
     *
     * @return  Ruleset 
     */
    protected function root() {
        while (true) {
            // drop empty lines
            while ($this->is_current_token_matched_by("\n")) {
                $this->advance("\n");
            }
            if ($this->is_end_of_file_reached()) {
                break;
            }

            // A top level statments is either..
            // ..an assignment to a variable.
            if ($this->is_current_token_matched_by(self::ASSIGNMENT_RE)) {
                $this->variable_assignment();
            }
            // ..or a rule declaration
            else {
                $this->rule_declaration();
            }

            if ($this->is_end_of_file_reached()) {
                break;
            }
            $this->advance("\n");
        }
        $this->purge_predefined_variables();
        return new Ruleset($this->variables, $this->rules);
    }

    // EXPRESSION TYPES

    /**
     * Fetch a rule mode from the stream.
     *
     * @return mixed
     */
    protected function rule_mode() {
        $this->is_current_token_matched_by(self::RULE_MODE_RE);
        $t = $this->current_symbol();
        $m = $this->current_match();
        $this->fetch_next_token();
        $mode = $t->null_denotation($m);
        return $mode;
    }

    /**
     * Fetch a string from the stream.
     *
     * @return  string
     */
    protected function string() {
        if (!$this->is_current_token_matched_by(self::STRING_RE)) {
            throw new ParserException("Expected string.");
        }
        $m = $this->current_match();
        $this->fetch_next_token();
        return  str_replace("\\\"", "\"",
                    str_replace("\\n", "\n",
                        $m[1]));
    }

    /**
     * Fetch a variable from the stream.
     *
     * @return  V\Variable
     */
    protected function variable($right_binding_power = 0) {
        $t = $this->current_symbol();
        $m = $this->current_match();
        $this->fetch_next_token();
        $left = $t->null_denotation($m);

        while ($right_binding_power < $this->token[0]->binding_power()) {
            $t = $this->current_symbol();
            $m = $this->current_match();
            $this->fetch_next_token();
            $left = $t->left_denotation($left, $m);
        }

        if (!($left instanceof V\Variable)) {
            throw new ParserException("Expected variable.");
        }

        return $left;
    }

    /**
     * Fetch a rule schema and its arguments from the stream.
     *
     * @return  array   (R\Schema, array)
     */
    protected function schema() {
        $t = $this->current_symbol();
        $m = $this->current_match();
        $this->fetch_next_token();
        $schema = $t->null_denotation($m);
        if (!($schema instanceof R\Schema)) {
            throw new ParserException("Expected name of a rule schema.");
        }
        return $schema;
    }

    // TOP LEVEL STATEMENTS

    /**
     * Process a variable assignment.
     *
     * @return  null
     */
    protected function variable_assignment() {
        $m = $this->current_match(); 
        $this->fetch_next_token();
        $def = $this->variable();
        $this->add_variable($m[1], $def);
    }

    /**
     * Process a rule declaration.
     *
     * @return  null
     */
    protected function rule_declaration() {
        if ($this->is_current_token_matched_by("only")) {
            $this->advance("only");
        }
        $var = $this->variable();
        $mode = $this->rule_mode();
        $schema = $this->schema();
        $this->is_start_of_rule_arguments = true;
        $arguments = $schema->fetch_arguments($this);
        assert('is_array($arguments)');
        $this->rules[] = new R\Rule($mode, $var, $schema, $arguments);
    }


    // HANDLING OF VARIABLES

    /**
     * Add a variable to the variables currently known.
     *
     * @param   string      $name
     * @param   V\Variable  $def
     * @return null
     */
    protected function add_variable($name, V\Variable $def) {
        assert('is_string($name)');
        if (array_key_exists($name, $this->variables)) {
            throw new ParserException("Variable '$name' already defined.");
        }
        assert('$def instanceof Lechimp\\Dicto\\Variables\\Variable');
        $this->variables[$name] = $def->withName($name);
    }

    /**
     * Get a predefined variable.
     *
     * @param   string  $name
     * @return  V\Variable
     */
    protected function get_variable($name) {
        if (!array_key_exists($name, $this->variables)) {
            throw new ParserException("Unknown variable '$name'.");
        }
        return $this->variables[$name];
    }

    /**
     * Add all predefined variables to the current set of variables.
     *
     * @return null
     */
    protected function add_predefined_variables() {
        foreach ($this->predefined_variables as $predefined_var) {
            $this->add_variable($predefined_var->name(), $predefined_var);
        }
    }

    /**
     * Purge all predefined variables from the current set of variables.
     *
     * @return null
     */
    protected function purge_predefined_variables() {
        foreach ($this->predefined_variables as $predefined_var) {
            unset($this->variables[$predefined_var->name()]);
        }
    }

    // IMPLEMENTATION OF ArgumentParser

    /**
     * @var bool
     */
    protected $is_start_of_rule_arguments = false;

    protected function maybe_fetch_argument_delimiter() {
        if (!$this->is_start_of_rule_arguments) {
            $this->advance_operator(",");
            $this->is_start_of_rule_arguments = false;
        }
    }

    /**
     * @inheritdoc
     */
    public function fetch_string() {
        $this->maybe_fetch_argument_delimiter();
        return $this->string();
    }

    /**
     * @inheritdoc
     */
    public function fetch_variable() {
        $this->maybe_fetch_argument_delimiter();
        return $this->variable();
    }
}


1		<?php
2		/******************************************************************************
3		* An implementation of dicto (scg.unibe.ch/dicto) in and for PHP.
4		*
5		* Copyright (c) 2016 Richard Klees <[email protected]>
6		*
7		* This software is licensed under The MIT License. You should have received
8		* a copy of the license along with the code.
9		*/
10
11		namespace Lechimp\Dicto\Definition;
12
13		use Lechimp\Dicto\Rules\Ruleset;
14		use Lechimp\Dicto\Variables as V;
15		use Lechimp\Dicto\Rules as R;
16
17		/**
18		* Parser for Rulesets.
19		*/
20		class RuleParser extends Parser implements ArgumentParser {
21		const ASSIGNMENT_RE = "(\w+)\s=\s";
22		const STRING_RE = "[\"]((([\\\\][\"])\|[^\"])+)[\"]";
23		const RULE_MODE_RE = "must\|can(not)?";
24
25		/**
26		* @var V\Variable[]
27		*/
28		protected $predefined_variables;
29
30		/**
31		* @var R\Schema[]
32		*/
33		protected $schemas;
34
35		/**
36		* @var R\Property[]
37		*/
38		protected $properties;
39
40		/**
41		* @var V\Variable[]
42		*/
43		protected $variables = array();
44
45		/**
46		* @var R\Rule[]
47		*/
48		protected $rules = array();
49
50		/**
51		* TODO: make arrays passed by reference as they get copied anyway.
52		*
53		* @param V\Variable[] $predefined_variables
54		* @param R\Schema[] $schemas
55		* @param V\Property[] $properties
56		*/
57	25	public function __construct( array $predefined_variables
58		, array $schemas
59		, array $properties) {
60		$this->predefined_variables = array_map(function(V\Variable $v) {
61	25	return $v;
62	25	}, $predefined_variables);
63		$this->schemas = array_map(function(R\Schema $s) {
64	25	return $s;
65	25	}, $schemas);
66		$this->properties = array_map(function(V\Property $p) {
67	25	return $p;
68	25	}, $properties);
69	25	parent::__construct();
70	25	}
71
72		// Definition of symbols in the parser
73
74		/**
75		* @inheritdocs
76		*/
77	25	protected function add_symbols_to(SymbolTable $table) {
78	25	$this->add_symbols_for_variables_to($table);
79
80	25	$this->add_symbols_for_rules_to($table);
81
82		// Strings
83	25	$table->symbol(self::STRING_RE);
84
85		// Assignment
86	25	$table->symbol(self::ASSIGNMENT_RE);
87
88		// Names
89		$table->literal("\w+", function (array &$matches) {
90	20	return $this->get_variable($matches[0]);
91	25	});
92
93		// End of statement
94	25	$table->symbol("\n");
95	25	}
96
97		/**
98		* @param SymbolTable
99		* @return null
100		*/
101	25	protected function add_symbols_for_variables_to(SymbolTable $table) {
102		// Any
103	25	$table->operator("{")
104		->null_denotation_is(function() {
105	7	$arr = array();
106	7	while(true) {
107	7	$arr[] = $this->variable(0);
108	7	if ($this->is_current_token_operator("}")) {
109	7	$this->advance_operator("}");
110	7	return new V\Any($arr);
111		}
112	7	$this->advance_operator(",");
113	7	}
114	25	});
115	25	$table->operator("}");
116	25	$table->operator(",");
117
118		// Except
119	25	$table->symbol("except", 10)
120		->left_denotation_is(function($left, array &$matches) {
		0 ignored issues – show Unused Code introduced 2016-08-01 18:35 UTC by Report Bug Copy Issue Report The parameter `$matches` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
121	7	if (!($left instanceof V\Variable)) {
122		throw new ParserException
123		("Expected a variable at the left of except.");
124		}
125	7	$right = $this->variable(10);
126	7	return new V\Except($left, $right);
127	25	});
128
129	25	$this->add_symbols_for_properties_to($table, $this->properties);
130	25	}
131
132		/**
133		* @param SymbolTable $table
134		* @param V\Property[] $properties
135		* @return null
136		*/
137	25	protected function add_symbols_for_properties_to(SymbolTable $table, array &$properties) {
138	25	foreach ($properties as $property) {
139	25	$table->symbol($property->parse_as().":", 20)
140		->left_denotation_is(function($left) use ($property) {
141	7	if (!($left instanceof V\Variable)) {
142		throw new ParserException
143		("Expected a variable at the left of \"with name:\".");
144		}
145	7	$this->is_start_of_rule_arguments = true;
146	7	$arguments = $property->fetch_arguments($this);
147	7	assert('is_array($arguments)');
148	7	return new V\WithProperty($left, $property, $arguments);
149	25	});
150	25	}
151	25	}
152
153		/**
154		* @param SymbolTable
155		* @return null
156		*/
157	25	protected function add_symbols_for_rules_to(SymbolTable $table) {
158		// Rules
159	25	$table->symbol("only");
160	25	$table->symbol(self::RULE_MODE_RE, 0)
161		->null_denotation_is(function (array &$matches) {
162	11	if ($matches[0] == "can") {
163	1	return R\Rule::MODE_ONLY_CAN;
164		}
165	10	if ($matches[0] == "must") {
166	7	return R\Rule::MODE_MUST;
167		}
168	3	if ($matches[0] == "cannot") {
169	3	return R\Rule::MODE_CANNOT;
170		}
171		throw new \LogicException("Unexpected \"".$matches[0]."\".");
172	25	});
173	25	$this->add_symbols_for_schemas_to($table, $this->schemas);
174	25	}
175
176		/**
177		* @param SymbolTable $table
178		* @param R\Schema[] $schemas
179		* @return null
180		*/
181	25	protected function add_symbols_for_schemas_to(SymbolTable $table, array &$schemas) {
182	25	foreach ($schemas as $schema) {
183	25	$table->symbol($schema->name())
184	25	->null_denotation_is(function(array &$_) use ($schema) {
		0 ignored issues – show Unused Code introduced 2016-08-01 18:35 UTC by Report Bug Copy Issue Report The parameter `$_` is not used and could be removed. This check looks from parameters that have been defined for a function or method, but which are not used in the method body. Loading history...
185	11	return $schema;
186	25	});
187	25	}
188	25	}
189
190		// IMPLEMENTATION OF Parser
191
192		/**
193		* @return Ruleset
194		*/
195	25	public function parse($source) {
196	25	$this->variables = array();
197	25	$this->rules = array();
198	25	$this->add_predefined_variables();
199	25	return parent::parse($source);
200		}
201
202		/**
203		* Parses the top level statements in the rules file.
204		*
205		* @return Ruleset
206		*/
207	16	protected function root() {
208	16	while (true) {
209		// drop empty lines
210	16	while ($this->is_current_token_matched_by("\n")) {
211	5	$this->advance("\n");
212	5	}
213	16	if ($this->is_end_of_file_reached()) {
214	6	break;
215		}
216
217		// A top level statments is either..
218		// ..an assignment to a variable.
219	15	if ($this->is_current_token_matched_by(self::ASSIGNMENT_RE)) {
220	8	$this->variable_assignment();
221	8	}
222		// ..or a rule declaration
223		else {
224	11	$this->rule_declaration();
225		}
226
227	15	if ($this->is_end_of_file_reached()) {
228	10	break;
229		}
230	6	$this->advance("\n");
231	6	}
232	16	$this->purge_predefined_variables();
233	16	return new Ruleset($this->variables, $this->rules);
234		}
235
236		// EXPRESSION TYPES
237
238		/**
239		* Fetch a rule mode from the stream.
240		*
241		* @return mixed
242		*/
243	11	protected function rule_mode() {
244	11	$this->is_current_token_matched_by(self::RULE_MODE_RE);
245	11	$t = $this->current_symbol();
246	11	$m = $this->current_match();
247	11	$this->fetch_next_token();
248	11	$mode = $t->null_denotation($m);
249	11	return $mode;
250		}
251
252		/**
253		* Fetch a string from the stream.
254		*
255		* @return string
256		*/
257	15	protected function string() {
258	15	if (!$this->is_current_token_matched_by(self::STRING_RE)) {
259		throw new ParserException("Expected string.");
260		}
261	15	$m = $this->current_match();
262	15	$this->fetch_next_token();
263	15	return str_replace("\\\"", "\"",
264	15	str_replace("\\n", "\n",
265	15	$m[1]));
266		}
267
268		/**
269		* Fetch a variable from the stream.
270		*
271		* @return V\Variable
272		*/
273	20	protected function variable($right_binding_power = 0) {
274	20	$t = $this->current_symbol();
275	20	$m = $this->current_match();
276	20	$this->fetch_next_token();
277	20	$left = $t->null_denotation($m);
278
279	20	while ($right_binding_power < $this->token[0]->binding_power()) {
280	10	$t = $this->current_symbol();
281	10	$m = $this->current_match();
282	10	$this->fetch_next_token();
283	10	$left = $t->left_denotation($left, $m);
284	10	}
285
286	20	if (!($left instanceof V\Variable)) {
287		throw new ParserException("Expected variable.");
288		}
289
290	20	return $left;
291		}
292
293		/**
294		* Fetch a rule schema and its arguments from the stream.
295		*
296		* @return array (R\Schema, array)
297		*/
298	11	protected function schema() {
299	11	$t = $this->current_symbol();
300	11	$m = $this->current_match();
301	11	$this->fetch_next_token();
302	11	$schema = $t->null_denotation($m);
303	11	if (!($schema instanceof R\Schema)) {
304		throw new ParserException("Expected name of a rule schema.");
305		}
306	11	return $schema;
307		}
308
309		// TOP LEVEL STATEMENTS
310
311		/**
312		* Process a variable assignment.
313		*
314		* @return null
315		*/
316	8	protected function variable_assignment() {
317	8	$m = $this->current_match();
318	8	$this->fetch_next_token();
319	8	$def = $this->variable();
320	8	$this->add_variable($m[1], $def);
321	8	}
322
323		/**
324		* Process a rule declaration.
325		*
326		* @return null
327		*/
328	11	protected function rule_declaration() {
329	11	if ($this->is_current_token_matched_by("only")) {
330	1	$this->advance("only");
331	1	}
332	11	$var = $this->variable();
333	11	$mode = $this->rule_mode();
334	11	$schema = $this->schema();
335	11	$this->is_start_of_rule_arguments = true;
336	11	$arguments = $schema->fetch_arguments($this);
337	11	assert('is_array($arguments)');
338	11	$this->rules[] = new R\Rule($mode, $var, $schema, $arguments);
339	11	}
340
341
342		// HANDLING OF VARIABLES
343
344		/**
345		* Add a variable to the variables currently known.
346		*
347		* @param string $name
348		* @param V\Variable $def
349		* @return null
350		*/
351	25	protected function add_variable($name, V\Variable $def) {
352	25	assert('is_string($name)');
353	25	if (array_key_exists($name, $this->variables)) {
354		throw new ParserException("Variable '$name' already defined.");
355		}
356	25	assert('$def instanceof Lechimp\\Dicto\\Variables\\Variable');
357	25	$this->variables[$name] = $def->withName($name);
358	25	}
359
360		/**
361		* Get a predefined variable.
362		*
363		* @param string $name
364		* @return V\Variable
365		*/
366	20	protected function get_variable($name) {
367	20	if (!array_key_exists($name, $this->variables)) {
368		throw new ParserException("Unknown variable '$name'.");
369		}
370	20	return $this->variables[$name];
371		}
372
373		/**
374		* Add all predefined variables to the current set of variables.
375		*
376		* @return null
377		*/
378	25	protected function add_predefined_variables() {
379	25	foreach ($this->predefined_variables as $predefined_var) {
380	25	$this->add_variable($predefined_var->name(), $predefined_var);
381	25	}
382	25	}
383
384		/**
385		* Purge all predefined variables from the current set of variables.
386		*
387		* @return null
388		*/
389	16	protected function purge_predefined_variables() {
390	16	foreach ($this->predefined_variables as $predefined_var) {
391	16	unset($this->variables[$predefined_var->name()]);
392	16	}
393	16	}
394
395		// IMPLEMENTATION OF ArgumentParser
396
397		/**
398		* @var bool
399		*/
400		protected $is_start_of_rule_arguments = false;
401
402	13	protected function maybe_fetch_argument_delimiter() {
403	13	if (!$this->is_start_of_rule_arguments) {
404		$this->advance_operator(",");
405		$this->is_start_of_rule_arguments = false;
406		}
407	13	}
408
409		/**
410		* @inheritdoc
411		*/
412	11	public function fetch_string() {
413	11	$this->maybe_fetch_argument_delimiter();
414	11	return $this->string();
415		}
416
417		/**
418		* @inheritdoc
419		*/
420	6	public function fetch_variable() {
421	6	$this->maybe_fetch_argument_delimiter();
422	6	return $this->variable();
423		}
424		}
425

lechimp-p / dicto.php

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RuleParser::add_symbols_for_rules_to() A

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