Module: Rouge::Seq::ASeq

Includes:
ISeq
Included in:
Array, Cons
Defined in:
lib/rouge/seq.rb

Overview

A partial implementation of ISeq. You supply #first and #next, it gives:

- #cons
- #to_s
- #seq
- #length (#count)
- #[]
- #==
- #each
- #map
- #to_a

Instance Method Summary collapse

Instance Method Details

#==(other) ⇒ Object 



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# File 'lib/rouge/seq.rb', line 90

def ==(other)
  if other.is_a?(ISeq)
    return self.to_a == other.to_a
  end

  if other.is_a?(::Array)
    return self.to_a == other
  end

  false
end

#[](idx) ⇒ Object 



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# File 'lib/rouge/seq.rb', line 74

def [](idx)
  return to_a[idx] if idx.is_a? Range

  cursor = self

  idx += self.length if idx < 0

  while idx > 0
    idx -= 1
    cursor = cursor.more
    return nil if cursor == Empty
  end

  cursor.first
end

#cons(head) ⇒ Object 



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# File 'lib/rouge/seq.rb', line 54

def cons(head)
  Cons.new(head, self)
end

#count ⇒ Object 



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# File 'lib/rouge/seq.rb', line 70

def count
  length
end

#each {|self.first| ... } ⇒ Object

Yields:



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# File 'lib/rouge/seq.rb', line 102

def each(&block)
  return self.enum_for(:each) if block.nil?

  yield self.first

  cursor = self.more
  while cursor != Empty
    yield cursor.first
    cursor = cursor.more
  end

  self
end

#first ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/rouge/seq.rb', line 42

def first; raise NotImplementedError; end

#inspect ⇒ Object 



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# File 'lib/rouge/seq.rb', line 34

def inspect
  to_s
end

#length ⇒ Object 



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# File 'lib/rouge/seq.rb', line 58

def length
  len = 0
  cursor = self

  while cursor != Empty
    len += 1
    cursor = cursor.more
  end

  len
end

#map(&block) ⇒ Object 



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# File 'lib/rouge/seq.rb', line 116

def map(&block)
  return self.enum_for(:map) if block.nil?

  result = []
  self.each {|elem| result << block.call(elem)}
  result
end

#more ⇒ Object 



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# File 'lib/rouge/seq.rb', line 45

def more
  nseq = self.next
  if nseq.nil?
    Empty
  else
    nseq
  end
end

#next ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/rouge/seq.rb', line 43

def next; raise NotImplementedError; end

#seq ⇒ Object 



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# File 'lib/rouge/seq.rb', line 38

def seq
  self
end

#to_a ⇒ Object 



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# File 'lib/rouge/seq.rb', line 124

def to_a
  r = []
  self.each {|e| r << e}
  r
end

#to_s ⇒ Object 



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# File 'lib/rouge/seq.rb', line 30

def to_s
  "(#{to_a.map(&:to_s).join " "})"
end