Pentothal
, (*1)
Higher order predicates library., (*2)
What?
An "higher order function" is a function that either returns a function or takes a function as argument., (*3)
A "functional predicate" is a function that receives one or more arguments (subject) and returns true or false., (*4)
This library is a collections of functions that return functional predicates., (*5)
Why?
In PHP there are some functions like array_map, array_filter, and so on, that take a functional predicate
as argument., (*6)
For example:, (*7)
$data = [
'foo',
1,
true,
'bar',
[],
''
];
$strings = array_filter($data, 'is_string'); // ['foo', 'bar', '']
This can be done thanks to the fact that a is_string is a named function., (*8)
But if we need something more complex, e.g. we also want to strip empty strings, we need to:, (*9)
$strings = array_filter($data, function($item) {
return is_string($item) && $item !== '';
});
One of the functions of this library is isType() that accepts a string representing a type
and returns a predicate that can be used to check subjects against that typoe., (*10)
Another of the functions of this library is isNotEmpty() that returns a predicate that verifies non-empty values., (*11)
Another function is combine() that takes an arbitrary number of predicates and returns a predicate
that returns true when all the combined predicates return true., (*12)
Using these 3 functions the code above can be written like this:, (*13)
use Pentothal as P;
$strings = array_filter($data, P\combine(P\isType('string'), P\isNotEmpty()));
All the functions in this library are in Pentothal namespace., (*14)
Installation
Served by Composer using gmazzap/pentothal., (*15)
List of functions
Here a list of all the functions currently provided by library (namespace omitted):, (*16)
General
-
always() Return a predicate that always return true
-
never() Return a predicate that always return false
isEmpty()isNotEmpty()
Comparison
isSame($value)isNotSame($value)isEqual($value)isNotEqual($value)-
match(string $regex)
notMatch(string $regex)
Type check
-
isType(string $type) Works with scalar types, classes and interfaces
isNotType(string $type)isInt()isNotInt()isFloat()isNotFloat()isNumber()isNotNumber()isString()isNotString()isBool()isNotBool()isNull()isNotNull()isObject()isNotObject()isArray()isNotArray()
Var filtering check
-
filterVar(int $filter, $options = null) Returns a predicate that applies filter_var() to subject using given filter and options.
isEmail()isNotEmail()isUrl()isNotUrl()isIp()isNotIp()isMac()isNotMac()
Size check
-
size(int $size) Verify elements count of arrays and countable objects and string length
sizeMax(int $size)sizeMaxStrict(int $size)sizeMin(int $size)sizeMinStrict(int $size)between(int $min, int $max)notBetween(int $min, int $max)betweenInner(int $min, int $max)notBetweenInner(int $min, int $max)betweenLeft(int $min, int $max)notBetweenLeft(int $min, int $max)betweenRight(int $min, int $max)notBetweenRight(int $min, int $max)
Elements check (for arrays and strings)
-
contain($item) Verify $item is present in arrays, or if both $item and subject are strings check the subject contain $item
notContain($item)-
startWith($item) Verify first element of arrays, or if both $item and subject are strings check the subject string starts with $item
-
notStartWith($item) Verify first element of arrays, or if both $item and subject are strings check the subject string starts with $item
endWith($item)notEndWith($item)
Elements check for arrays only
-
anyOfValues(array $values) Verify array subject for intersection with given values
notAnyOfValues(array $values)-
anyOf(...$values) Like anyOfValues but with variadic arguments
notAnyOf(...$values)
Elements check for arrays and objects
-
hasValue($value) Return a predicate that checks an array or a traversable object to find an element equal to value given
hasNotValue($value)hasValues(array $value)hasNotValues(array $values)hasAnyOfValues(array $values)hasNotAnyOfValues(array $values)
Object properties check (works with associative arrays as well)
hasKey(string $key)hasKeys(array $keys)hasNotKeys(array $keys)hasAnyOfKeys(array $keys)hasNotAnyOfKeys(array $keys)keyIs(string $key, $value)keyIsNot(string $key, $value)keyIsAnyOf(string $key, array values)keyIsNotAnyOf(string $key, array $values)keyIsType(string $key, string $type)keyInNotType(string $key, string $type)-
keyApply(string $key, callable $predicate) Return a predicate that applies a predicate to a key of the subject
Object methods check
hasMethod(string $method)hasNotMethod(string $method)methodReturn(string $method, $value, array $methodArgs = [])methodNotReturn(string $method, $value, array $methodArgs = [])methodReturnAnyOf(string $method, array $values, array $methodArgs = [])methodNotReturnAnyOf(string $method, array $values, array $methodArgs = [])methodReturnType(string $method, string $type, array $methodArgs = [])methodNotReturnType(string $method, string $type, array $methodArgs = [])methodReturnEmpty(string $method, array $methodArgs = [])methodReturnNotEmpty(string $method, array $methodArgs = [])-
methodReturnApply(string $method, callable $predicate, array $methodArgs = []) Return a predicate that applies a predicate return value of given method of the subject
Bulk
-
bulk(callable $predicate) Return a predicate that applies the same predicate to an array of values and returns true when the given predicate return true for all values
-
bulkPool(callable $predicate) Like bulk() but returned predicate return true the given predicate returns true for any of the values
Predicates composition
-
negate(callable $predicate) Return a predicate that return true when given predicate return false and viceversa
-
combine(...$predicates) Return a predicate that returns true when all the given predicates returns true
-
pool(...$predicates) Return a predicate that returns true when any of the given predicates returns true
-
combineCallbacks(array $predicates) Like combine() but accepts an array of predicates
-
poolCallbacks(...$predicates) Like pool() but accepts an array of predicates
-
combineMap(array $predicates) Takes a map of predicates and return a predicates that applies to a map value, returns true when all the predicates return true
-
poolMap(array $predicates) Like combineMap, but the returned predicates return true when any the predicates returns true
-
applyAfter(callable $transformation, callable $predicate) Returns a predicate
which returns the result of the predicate, after it has been applied
the the input value, transformed by the $transformation function.
Example
use Pentothal as P;
$data = ['yes', 'no', 'Yes', 'No', 'YES', 'NO' ];
$yes = array_filter($data, P\applyAfter('strtolower', isSame('yes'))); // ['yes', 'Yes', 'YES']
Quite complex example
use Pentothal as P;
// some example data
$countableOne = new \ArrayObject(['foo' => 'bar']);
$countableTwo = new \ArrayObject(['a' => 'a', 'b' => 'b']);
$plainObj = new \stdClass();
$string1 = 'a';
$string3 = 'abc';
$number1 = 1;
$number3 = 3;
$list = [
'a' => $countableOne,
'b' => $countableTwo,
'c' => $plainObj,
'd' => $string1,
'e' => $string3,
'f' => $number1,
'g' => $number3
];
$predicate = P\combine(
P\pool(P\isNotObject(), P\isType('Countable')), // filter out: ['c' => $plainObj]
P\pool(P\isNotString(), P\size(3)), // filter out: ['d' => $string1]
P\pool(P\isString(), P\size(1)) // filter out: ['a' => $countableTwo, 'g' => $number3]
);
$negatePredicate = negate($predicate);
$in = array_filter($list, $predicate);
$out = array_filter($list, $negatePredicate);
var_dump($in); // array('a' => $countableOne, 'e' => $string3, 'f' => $number1];
var_dump($out); // array('b' => $countableTwo, 'c' => $plainObj, 'd' => $string1, 'g' => $number3];
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