Class: Rope::BasicRope

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/rope/basic_rope.rb

Overview

BasicRope is a data-type-agnostic Rope data structure. The data type is typically a string but can be anything that implements the following methods:

  • length - integer length of a unit of the data type

  • slice - break a unit of the data type into two pieces on an index boundary

  • + - join two pieces of the data type together

    • alias for slice

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(arg = nil) ⇒ BasicRope

Initializes a new rope



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# File 'lib/rope/basic_rope.rb', line 28

def initialize(arg=nil)
  case arg
  when BasicNode
    @root = arg
  when NilClass
    @root = LeafNode.new(primitive_type.new)
  when primitive_type
    @root = LeafNode.new(arg)
  when self.class, InteriorNode
    @root = LeafNode.new(arg.to_primitive)
  else
    raise ArgumentError, "#{arg} is not a #{primitive_type}"
  end
end

Class Method Details

.rope_for_type(type, &block) ⇒ Object 



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# File 'lib/rope/basic_rope.rb', line 17

def self.rope_for_type(type, &block)
  Class.new(self) do
    define_method :primitive_type do
      type
    end
    
    class_eval &block if block_given?
  end
end

Instance Method Details

#+(other) ⇒ Object

Concatenates this rope with another rope or string



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# File 'lib/rope/basic_rope.rb', line 46

def +(other)
  self.class.new(concatenate(other))
end

#<<(rhs) ⇒ Object 



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# File 'lib/rope/basic_rope.rb', line 82

def <<(rhs)
  self[length] = rhs
end

#==(other) ⇒ Object

Tests whether this rope is equal to another rope



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# File 'lib/rope/basic_rope.rb', line 51

def ==(other)
  to_primitive == (BasicRope === other ? other.to_primitive : other)
end

#[]=(index, length = 1, rhs) ⇒ Object 



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# File 'lib/rope/basic_rope.rb', line 76

def []=(index, length=1, rhs)
  @root = @root.replace!(index, length, rhs)
  self
end

#dup ⇒ Object

Creates a copy of this rope



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# File 'lib/rope/basic_rope.rb', line 56

def dup
  root.freeze #Prevents errors when 
  self.class.new(root)
end

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

Gets a slice of this rope



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# File 'lib/rope/basic_rope.rb', line 62

def slice(*args)
  slice = root.slice(*args)

  case slice
  when Fixnum # slice(Fixnum) returns a plain Fixnum
    slice
  when BasicNode, primitive_type # create a new Rope with the returned tree as the root
    self.class.new(slice)
  else
    nil
  end
end