PHP - Sequence Functions

Introduction to Sequence interface

A Sequence can describe the behavior of values arranged in a single, linear dimension. Some languages can refer to this as a List. It is similar to an array that uses incremental integer keys, with the exception of a few characteristics.

• Values can always be indexed as [0, 1, 2, …, size - 1].
• Only allowed to access values by index in the range [0, size - 1].

Use cases

• Wherever we can use an array as a list (not concerned with keys).
• A more efficient alternative to SplDoublyLinkedList and SplFixedArray.

Interface synopsis

Ds\Sequence implements Ds\Collection {
   /* Methods */
   abstract public void allocate( int $capacity )
   abstract public void apply( callable $callback )
   abstract public int capacity( void ) 
   abstract public bool contains([ mixed $...values ] )
   abstract public Ds\Sequence filter([ callable $callback ] )
   abstract public mixed find( mixed $value )
   abstract public mixed first( void )
   abstract public mixed get( int $index )
   abstract public void insert( int $index [, mixed $...values ] )
   abstract public string join([ string $glue ] )
   abstract public mixed last( void )
   abstract public Ds\Sequence map( callable $callback )
   abstract public Ds\Sequence merge( mixed $values )
   abstract public mixed pop( void )
   abstract public void push([ mixed $...values ] )
   abstract public mixed reduce( callable $callback [, mixed $initial ] )
   abstract public mixed remove( int $index )
   abstract public void reverse( void )
   abstract public Ds\Sequence reversed( void )
   abstract public void rotate( int $rotations )
   abstract public void set( int $index , mixed $value )
   abstract public mixed shift( void )
   abstract public Ds\Sequence slice( int $index [, int $length ] )
   abstract public void sort([ callable $comparator ] )
   abstract public Ds\Sequence sorted([ callable $comparator ] )
   abstract public number sum( void )
   abstract public void unshift([ mixed $values ] )
}

Predefined Constants

Ds\Map::MIN_CAPACITY