Class: Hibiki::Derived

Inherits:
Object
  • Object
show all
Includes:
Observer, Trackable
Defined in:
lib/hibiki/derived.rb

Overview

---- derived / computed -----------------------------------------------------

Instance Method Summary collapse

Methods included from Observer

#add_source, #clear_sources, #sources, #sources_changed?

Methods included from Trackable

#changed_from?, #notify, #register_dependency, #subscribers, #unsubscribe

Constructor Details

#initialize(equals: nil, &block) ⇒ Derived

equals: per-signal equality (Solid's createMemo takes it too). A derived has no write gate, so it matters only at the flush gate — observers ask changed_from?, which consults it (see Trackable).



12
13
14
15
16
 
# File 'lib/hibiki/derived.rb', line 12

def initialize(equals: nil, &block)
  @block = block
  @equals = equals
  @dirty = true
end

Instance Method Details

#call ⇒ Object

Solid signals are getter functions; sig.() reads (and registers).



32
 
# File 'lib/hibiki/derived.rb', line 32

def call = value

#inspect ⇒ Object 



42
 
# File 'lib/hibiki/derived.rb', line 42

def inspect = "#<Hibiki::Derived #{@dirty ? 'dirty' : @value.inspect}>"

#invalidate ⇒ Object 



34
35
36
37
38
39
 
# File 'lib/hibiki/derived.rb', line 34

def invalidate
  return if @dirty

  @dirty = true
  notify # propagate dirtiness downstream (derived-of-derived, effects)
end

#peek ⇒ Object

Read without subscribing the reader. A dirty derived still recomputes (collecting its own deps as usual) — peek only skips the outward edge.



26
27
28
29
 
# File 'lib/hibiki/derived.rb', line 26

def peek
  recompute if @dirty
  @value
end

#to_s ⇒ Object 



41
 
# File 'lib/hibiki/derived.rb', line 41

def to_s = value.to_s

#value ⇒ Object 



18
19
20
21
22
 
# File 'lib/hibiki/derived.rb', line 18

def value
  recompute if @dirty
  register_dependency
  @value
end