Pkey:
Filter:

Pkey : Pattern : AbstractFunction : Object

access a key in an event stream
Source: Patterns.sc

Description

Pkey simplifies backward access to values in an event being processed by Pbind or another event pattern.

Class Methods

Pkey.new(key, repeats)

Arguments:

key

The name of the event variable to read from.

repeats

The number of items returned before finishing. Using nil, the default value, makes the stream infinite.

Inherited class methods

Instance Methods

Inherited instance methods

Undocumented instance methods

.asStream

.embedInStream(inval)

.key

.key = value

.repeats

.repeats = value

Examples

// \b should thus take twice the value of \a in each event:
p = Pbind(\a, Pwhite(1, 10, inf), \b, Pkey(\a) * 2).asStream;


p.next(())    // for Pbind, must pass in a default event even if empty

( 'a': 10, 'b': 20 )
( 'a': 2, 'b': 4 )
( 'a': 5, 'b': 10 )
( 'a': 4, 'b': 8 )
( 'a': 2, 'b': 4 )