Class: JSONP3::SliceSelector

Inherits:
Selector show all
Defined in:
lib/json_p3/selector.rb

Overview

The slice selector selects a range of elements from an array.

Instance Attribute Summary collapse

Attributes inherited from Selector

#token

Instance Method Summary collapse

Methods inherited from Selector

#singular?

Constructor Details

#initialize(env, token, start, stop, step) ⇒ SliceSelector

Returns a new instance of SliceSelector.


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# File 'lib/json_p3/selector.rb', line 168

def initialize(env, token, start, stop, step)
  super(env, token)
  @start = start
  @stop = stop
  @step = step || 1
end

Instance Attribute Details

#start ⇒ Object (readonly)

Returns the value of attribute start.


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# File 'lib/json_p3/selector.rb', line 166

def start
  @start
end

#step ⇒ Object (readonly)

Returns the value of attribute step.


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# File 'lib/json_p3/selector.rb', line 166

def step
  @step
end

#stop ⇒ Object (readonly)

Returns the value of attribute stop.


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# File 'lib/json_p3/selector.rb', line 166

def stop
  @stop
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 


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# File 'lib/json_p3/selector.rb', line 208

def ==(other)
  self.class == other.class &&
    @start == other.start &&
    @stop == other.stop &&
    @step == other.step &&
    @token == other.token
end

#hash ⇒ Object 


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# File 'lib/json_p3/selector.rb', line 218

def hash
  [@start, @stop, @step, @token].hash
end

#resolve(node) ⇒ Object 


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# File 'lib/json_p3/selector.rb', line 175

def resolve(node)
  return [] unless node.value.is_a?(Array)

  length = node.value.length
  return [] if length.zero? || @step.zero?

  norm_start = normalized_start(length)
  norm_stop = normalized_stop(length)

  nodes = []

  if @step.positive?

    for i in (norm_start...norm_stop).step(@step) # rubocop:disable Style/For
      nodes << node.new_child(node.value[i], i)
    end
  else
    i = norm_start
    while i > norm_stop
      nodes << node.new_child(node.value[i], i)
      i += @step
    end
  end
  nodes
end

#to_s ⇒ Object 


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# File 'lib/json_p3/selector.rb', line 201

def to_s
  start = @start || ""
  stop = @stop || ""
  step = @step || 1
  "#{start}:#{stop}:#{step}"
end