Class: AbstractMapper::Node

Inherits:
Object
  • Object
show all
Includes:
Attributes, Comparable
Defined in:
lib/abstract_mapper/node.rb

Overview

An immutable node of the abstract syntax tree (AST), that describes either some “end-up” transformation, or a level of nested input data.

Every node is expected to accept attributes and (possibly) block, and implement ‘#transproc` that implements the `#call` method to transform input data to the output.

Nodes describe only the structure of AST, they know neither how to build the tree with DSL (see [AbstractMapper::Builder]), nor how to optimize it later (see [AbstractMapper::Optimizer]).

Direct Known Subclasses

Branch

Instance Attribute Summary collapse

Attributes included from Attributes

#attributes

Instance Method Summary collapse

Methods included from Attributes

included

Constructor Details

#initialize(_ = {}, &block) ⇒ Node

Returns a new instance of Node.



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# File 'lib/abstract_mapper/node.rb', line 30

def initialize(_ = {}, &block)
  super
  @block      = block
  IceNine.deep_freeze(self)
end

Instance Attribute Details

#block ⇒ Proc (readonly)

Returns The block given to initializer.

Returns:

  • (Proc) —

    The block given to initializer



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# File 'lib/abstract_mapper/node.rb', line 27

def block
  @block
end

Instance Method Details

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

Compares the node to another one by type and attributes

Parameters:

  • other (Object)

Returns:

  • (Boolean) 


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# File 'lib/abstract_mapper/node.rb', line 69

def ==(other)
  other.instance_of?(self.class) && attributes.eql?(other.attributes)
end

#inspect ⇒ String

Returns a human-readable string representating the node

Returns:

  • (String) 


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# File 'lib/abstract_mapper/node.rb', line 51

def inspect
  "<#{self}>"
end

#to_s ⇒ String

Converts the node into string with its name and attributes

Returns:

  • (String) 


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# File 'lib/abstract_mapper/node.rb', line 59

def to_s
  "#{__name__}#{__attributes__}"
end

#transproc ⇒ Transproc::Function

This method is abstract.

The transformation function for the branch

Returns:

  • (Transproc::Function) 


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# File 'lib/abstract_mapper/node.rb', line 43

def transproc
  Functions[:identity]
end