Class: StrokeDB::LazyMappingArray

Inherits:
Array show all
Defined in:
lib/strokedb/util/lazy_mapping_array.rb

Overview

Lazy loads items from array applying procs on each read and write.

Example:

@ary = 10

applies “unmap proc” to new item value.

@ary.at(i)

applies “map proc” to value just have been read.

StrokeDB uses this class to “follow” links to other documents found in slots in a lazy manner.

player:

model: [@#8b195509-f9c4-4fea-90c9-425b38bdda3e.ea5eda78-d410-44be-8b14-f4e33f6fa047]
generation: 4

when model collection item is fetched, reference followed and turned into document instance with mapping proc of lazy mapping array.

Direct Known Subclasses

ArraySlotValue

Constant Summary

Constants inherited from Array

Array::SDATPTAGS

Instance Method Summary collapse

Methods inherited from Array

#stroke_diff, #stroke_merge, #stroke_patch, #to_raw

Constructor Details

#initialize(*args) ⇒ LazyMappingArray

Returns a new instance of LazyMappingArray.



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 24

def initialize(*args)
  @map_proc = proc {|v| v}
  @unmap_proc = proc {|v| v}
  super(*args)
end

Instance Method Details

#-(a) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 126

def -(a)
  _substract(a.map {|v| @unmap_proc.call(v) })
end

#==(arr) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 139

def ==(arr)
  to_a == arr
end

#[](*args) ⇒ Object Also known as: slice 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 41

def [](*args)
  r = _square_brackets(*args)
  if (args.first.is_a?(Range) || args.size == 2) && r.is_a?(Array)
    LazyMappingArray.new(r).map_with(&@map_proc).unmap_with(&@unmap_proc)
  else
    @map_proc.call(r)
  end
end

#[]=(*args) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 52

def []=(*args)
  value = args.pop
  if (args.first.is_a?(Range) || args.size == 2) && value.is_a?(Array)
    args << value.map{|e| @unmap_proc.call(e) }
    _square_brackets_set(*args)
  else
    _square_brackets_set(args[0], @unmap_proc.call(value))
  end
end

#_at ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 62

alias :_at :at

#_each ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 75

alias :_each :each

#_find ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 115

alias :_find :find

#_include? ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 130

alias :_include? :include?

#_index ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 120

alias :_index :index

#_map ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 82

alias :_map :map

#_pop ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 105

alias :_pop :pop

#_push ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 94

alias :_push :push

#_shift ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 110

alias :_shift :shift

#_square_brackets ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 40

alias :_square_brackets :[]

#_square_brackets_set ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 51

alias :_square_brackets_set :[]=

#_substract ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 125

alias :_substract :-

#_unshift ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 100

alias :_unshift :unshift

#_zip ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 89

alias :_zip :zip

#at(index) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 63

def at(index)
  @map_proc.call(_at(index))
end

#class ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 143

def class
  Array
end

#each ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 76

def each
  _each do |val|
    yield @map_proc.call(val)
  end
end

#find ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 116

def find
  _find {|value| yield(@map_proc.call(value))}
end

#first ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 67

def first
  at(0)
end

#include?(v) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 131

def include?(v)
  _include?(@unmap_proc.call(v))
end

#index(v) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 121

def index(v)
  _index(@unmap_proc.call(v))
end

#last ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 71

def last
  at(size-1)
end

#map ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 83

def map
  _map do |val|
    yield @map_proc.call(val)
  end
end

#map_with(&block) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 30

def map_with(&block)
  @map_proc = block
  self
end

#pop ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 106

def pop
  @map_proc.call(_pop)
end

#push(value) ⇒ Object Also known as: << 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 95

def push(value)
  _push(@unmap_proc.call(value))
end

#shift ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 111

def shift
  @map_proc.call(_shift)
end

#to_a ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 135

def to_a
   Array.new(map{|v| v})
end

#unmap_with(&block) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 35

def unmap_with(&block)
  @unmap_proc = block
  self
end

#unshift(value) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 101

def unshift(value)
  _unshift(@unmap_proc.call(value))
end

#zip(*args) ⇒ Object 



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# File 'lib/strokedb/util/lazy_mapping_array.rb', line 90

def zip(*args)
  map{|v|v}.zip(*args)
end