Class: Fr::TZipper::DanglingCursor

Inherits:
AbstractCursor show all
Defined in:
lib/fr/tzipper/dangling_cursor.rb

Instance Attribute Summary collapse

Querying the Tree Location collapse

Traversing the Tree collapse

Editing the Tree collapse

Instance Method Summary collapse

Methods inherited from AbstractCursor

#append_child, #between, #child, #children, #dangle, #descendant, #down, #flatten, #insert_left, #insert_right, #prepend_child, #root

Constructor Details

#initialize(parent) ⇒ DanglingCursor

Returns a new instance of DanglingCursor.



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 9

def initialize(parent)
  @parent = parent
end

Instance Attribute Details

#parent ⇒ AbstractCursor (readonly)

Returns:



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 7

def parent
  @parent
end

Instance Method Details

#delete ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 94

def delete
  self
end

#depth ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 38

def depth
  @parent.depth + 1
end

#first ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 73

def first
  self
end

#first? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fr/tzipper/dangling_cursor.rb', line 43

def first?
  true
end

#inspect ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 101

def inspect
  "Cursor(..., ___)"
end

#last ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 78

def last
  self
end

#last? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fr/tzipper/dangling_cursor.rb', line 48

def last?
  true
end

#leaf? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fr/tzipper/dangling_cursor.rb', line 28

def leaf?
  true
end

#next ⇒ Object

Raises:



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 61

def next
  raise Errors::ZipperError,
    "cannot move to next after last node"
end

#node ⇒ Object

Raises:



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 14

def node
  raise Errors::ZipperError,
    "DanglingCursor#node should not be called"
end

#path ⇒ Object 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 20

def path
  Hole.new([], @parent.path.parent, [])
end

#prev ⇒ Object

Raises:



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 67

def prev
  raise Errors::ZipperError,
    "cannot move to prev before first node"
end

#replace(node) ⇒ Object Also known as: prepend, append 



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 86

def replace(node)
  @parent.append_child(node)
end

#root? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fr/tzipper/dangling_cursor.rb', line 33

def root?
  false
end

#up ⇒ AbstractCursor

Returns:



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# File 'lib/fr/tzipper/dangling_cursor.rb', line 56

def up
  @parent
end