Class: Bmg::Operator::Autowrap

Inherits:
Object
  • Object
show all
Includes:
Unary
Defined in:
lib/bmg/operator/autowrap.rb

Overview

Autowrap operator.

Autowrap can be used to structure tuples ala Tutorial D’ wrap, but it works with conventions instead of explicit wrapping, and supports multiple levels or wrapping.

Examples:

[{ a: 1, b_x: 2, b_y: 3 }]     => [{ a: 1, b: { x: 2, y: 3 } }]
[{ a: 1, b_x_y: 2, b_x_z: 3 }] => [{ a: 1, b: { x: { y: 2, z: 3 } } }]

Autowrap supports the following options:

  • ‘postprocessor: :nil|:none|:delete|Hash|Proc` see NoLeftJoinNoise

  • ‘split: String` the seperator to use to split keys, defaults to `_`

Defined Under Namespace

Classes: NoLeftJoinNoise

Constant Summary collapse

DEFAULT_OPTIONS = 
{
  :postprocessor => :none,
  :split => "_"
}

Constants included from Algebra

Algebra::METHODS

Instance Attribute Summary

Attributes included from Unary

#operand, #type

Instance Method Summary collapse

Methods included from Unary

#_visit, #operands

Methods included from Bmg::Operator

#inspect, #to_s

Methods included from Relation

#debug, #delete, empty, #empty?, #insert, new, #one, #one_or_nil, #to_json, #update, #visit, #ys_by_x

Methods included from Algebra

#allbut, #autosummarize, #constants, #extend, #group, #image, #matching, #page, #project, #rename, #restrict, #rxmatch, #spied, #union, #unspied

Constructor Details

#initialize(type, operand, options = {}) ⇒ Autowrap

Returns a new instance of Autowrap.



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# File 'lib/bmg/operator/autowrap.rb', line 28

def initialize(type, operand, options = {})
  @type = type
  @operand = operand
  @original_options = options
  @options = DEFAULT_OPTIONS.merge(options)
  @options[:postprocessor] = NoLeftJoinNoise.new(@options[:postprocessor])
end

Instance Method Details

#each ⇒ Object 



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# File 'lib/bmg/operator/autowrap.rb', line 42

def each
  @operand.each do |tuple|
    yield autowrap(tuple)
  end
end

#to_ast ⇒ Object 



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# File 'lib/bmg/operator/autowrap.rb', line 48

def to_ast
  [ :autowrap, operand.to_ast, @original_options.dup ]
end