library perrys-lambda

perryflynn/perrys-lambda

Implementation of lambda expressions for PHP.

This project tries to implement C# .NET lambda expressions in PHP., _(*1)

, _(*2)

Status

In development, semi-stable API., _(*3)

Composer

Packagegist, _(*4)

composer require perryflynn/perrys-lambda

Features

• Implements many C# .NET like lambda expressions
• Support for auto conversion of records in custom objects
• Support for iteation and foreach
• Support for generator (helps with call-by-reference in loops)
• Helper classes for filesystem access
• Helper classes for CSV file parsing

Lambda methods

| Method | Description | |--------|-------------| *OrDefault | Define return value if expression has no hit, available for many methods first | Get the first record last | Get the last record single | Get the single record, if count!=0, throw exception take | Get the first X records skip | Skip the first X records where | Filter records by callable expression whereFirst | Get first record matching the callable expression groupby | Group records by callable expression distrinct | Eliminate duplicate records bei callable expression intersect | Returns the intersection of two ArrayList's except | Returns the bidirectional diffrence of two ArrayList's any | Returns true if callable expression returns at least one record true all | Returns true if callable expression returns for all records true select | Get an array of the values returned by callable expression selectMany | Get an array of all values, arrays will be merged joinString | Join a string from values returned by callable expression each | Execute callable expression on each record sum | Get the sum of numberic return values from callable expression min | Get the smallest of numberic return values from callable expression max | Get the biggest of numberic return values from callable expression avg | Get the average of numberic return values from callable expression order | Start sorting, begin ascending, more possible by thenBy / thenByDesc orderDesc | Start sorting, begin descending, more possible by thenBy / thenByDesc, _(*5)

Basic usage

$basic = new \PerrysLambda\ArrayList(array(1,2,3,4,5,6,7,8,9));

$basic->where(function($n) { return $n<=3; }); // Returns ArrayList of [1,2,3]
$basic->where(function($n) { return $n<=3; })->sum(); // Returns 6

Basic usage with ObjectArray and Strings instead of callables

$data = array(
    array('name'=>'Frank', age=>12),
    array('name'=>'Gene', age=>42),
    array('name'=>'Jessie', age=>31),
    array('name'=>'Carl', age=>55),
);

$list = \PerrysLambda\ArrayList::asObjectArray($data);
$list->select('age')->sum(); // Returns 140
$list->where(function($v) { return $v->age > 40; })->select('age')->sum(); // Returns 97

Deserialize / Serialize

• Deserialize json data
• Modify data
• Serialize again into json data
• Display modified json data

// examples/serialize.php

use PerrysLambda\ArrayList;
use PerrysLambda\ObjectArray;
use PerrysLambda\IArrayable;
use PerrysLambda\Converter\ItemConverter;
use PerrysLambda\Serializer\Serializer;
use PerrysLambda\Serializer\DateTimeSerializer;
use PerrysLambda\Serializer\BooleanSerializer;
use PerrysLambda\Converter\ListConverter;

// Testdata
$rawstring = <<<HEREDOC
{"foo":419995191,"bar":1492275950.5668,"foobar":"true","barfoo":"2018-12-08T20:24:41+0100","test":"Ivan"}
{"foo":92059366,"bar":1492275950.5669,"foobar":"false","barfoo":"2021-04-11T04:16:27+0200","test":"Gadget"}
{"foo":174207424,"bar":1492275950.5671,"foobar":"true","barfoo":"2017-07-29T21:53:36+0200","test":"Timmy"}
{"foo":624519809,"bar":1492275950.5672,"foobar":"false","barfoo":"2018-06-23T20:22:49+0200","test":"Alice"}
HEREDOC;

// Split into lines
$rawlines = explode("\n", $rawstring);

// Parse lines to one array with fields per line
$deserializer = function(&$row, &$key)
{
    if(is_string($row))
    {
        $data = json_decode($row, true);
        if(is_array($data))
        {
            $row = new ObjectArray($data);
        }
        else
        {
            return false;
        }
    }
    return true;
};

$serializer = function(&$row, &$key)
{
    if($row instanceof IArrayable)
    {
        $row = $row->toArray();
    }

    if(is_array($row))
    {
        $row = json_encode($row);
        if(is_string($row))
        {
            return true;
        }
    }
    return false;
};

// Row serializer
$fieldconverter = new ItemConverter();
$fieldconverter->setSerializer(new Serializer($serializer, $deserializer));

// Field serializer
$fieldconverter->setFieldSerializers(array(
    "barfoo" => DateTimeSerializer::fromIsoFormat(),
    "foobar" => new BooleanSerializer(),
));

// Create converter
$conv = new ListConverter();
$conv->setItemConverter($fieldconverter);
$conv->setArraySource($rawlines);

// Load raw data into ArrayList
$list = new ArrayList($conv);

// Modify data
$list
    ->where(function($v) { return $v->foobar===true; })
    ->each(function($v) { $v->foo = $v->foo+1; });

// Serialize modified data
$serlines = $list->serialize();
var_dump($serlines);

More examples

See the unit tests, _(*6)