Class: DataMapper::Query::Conditions::AbstractOperation

Inherits:
Object
  • Object
show all
Extended by:
Equalizer
Includes:
Assertions, Enumerable
Defined in:
lib/dm-core/query/conditions/operation.rb

Overview

class Operation

Direct Known Subclasses

AndOperation, NotOperation, NullOperation, OrOperation

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Equalizer

equalize

Methods included from Assertions

#assert_kind_of

Instance Attribute Details

#operands ⇒ Set<AbstractOperation, AbstractComparison, Array> (readonly) Also known as: children

Returns the child operations and comparisons



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# File 'lib/dm-core/query/conditions/operation.rb', line 89

def operands
  @operands
end

#parent ⇒ AbstractOperation

Returns the parent operation



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# File 'lib/dm-core/query/conditions/operation.rb', line 81

def parent
  @parent
end

Class Method Details

.descendants ⇒ Set

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns the classes that inherit from AbstractComparison



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# File 'lib/dm-core/query/conditions/operation.rb', line 99

def self.descendants
  @descendants ||= DescendantSet.new
end

.inherited(descendant) ⇒ undefined

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Hook executed when inheriting from AbstractComparison



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# File 'lib/dm-core/query/conditions/operation.rb', line 108

def self.inherited(descendant)
  descendants << descendant
end

.slug(slug = nil) ⇒ Symbol

Get and set the slug for the operation class



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# File 'lib/dm-core/query/conditions/operation.rb', line 121

def self.slug(slug = nil)
  slug ? @slug = slug : @slug
end

Instance Method Details

#<<(operand) ⇒ self

Add an operand to the operation



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# File 'lib/dm-core/query/conditions/operation.rb', line 202

def <<(operand)
  assert_valid_operand_type(operand)
  @operands << relate_operand(operand)
  self
end

#clear ⇒ self

Clear the operands



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# File 'lib/dm-core/query/conditions/operation.rb', line 284

def clear
  @operands.clear
  self
end

#difference(other) ⇒ AndOperation Also known as: -

Return the difference of the operation and another operand



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# File 'lib/dm-core/query/conditions/operation.rb', line 262

def difference(other)
  Operation.new(:and, dup, Operation.new(:not, other.dup)).minimize
end

#each {|operand| ... } ⇒ self

Iterate through each operand in the operation

Yields:

  • (operand) —

    yields to each operand

Yield Parameters:



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# File 'lib/dm-core/query/conditions/operation.rb', line 158

def each
  @operands.each { |op| yield op }
  self
end

#empty? ⇒ Boolean

Test to see if there are operands



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# File 'lib/dm-core/query/conditions/operation.rb', line 169

def empty?
  @operands.empty?
end

#first ⇒ AbstractOperation, ...

Get the first operand



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# File 'lib/dm-core/query/conditions/operation.rb', line 141

def first
  each { |operand| return operand }
  nil
end

#intersection(other) ⇒ AndOperation Also known as: &

Return the intersection of the operation and another operand



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# File 'lib/dm-core/query/conditions/operation.rb', line 247

def intersection(other)
  Operation.new(:and, dup, other.dup).minimize
end

#merge(operands) ⇒ self

Add operands to the operation



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# File 'lib/dm-core/query/conditions/operation.rb', line 217

def merge(operands)
  operands.each { |op| self << op }
  self
end

#minimize ⇒ self

Minimize the operation



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# File 'lib/dm-core/query/conditions/operation.rb', line 274

def minimize
  self
end

#negated? ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Test if the operation is negated

Defaults to return false.



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# File 'lib/dm-core/query/conditions/operation.rb', line 307

def negated?
  parent = self.parent
  parent ? parent.negated? : false
end

#one? ⇒ Boolean

Test to see if there is one operand



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# File 'lib/dm-core/query/conditions/operation.rb', line 179

def one?
  @operands.size == 1
end

#slug ⇒ Symbol

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Return the comparison class slug



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# File 'lib/dm-core/query/conditions/operation.rb', line 131

def slug
  self.class.slug
end

#sorted_operands ⇒ Array<AbstractOperation, AbstractComparison, Array>

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Return a list of operands in predictable order



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# File 'lib/dm-core/query/conditions/operation.rb', line 318

def sorted_operands
  sort_by { |op| op.hash }
end

#to_s ⇒ String

Return the string representation of the operation



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# File 'lib/dm-core/query/conditions/operation.rb', line 295

def to_s
  empty? ? '' : "(#{sort_by { |op| op.to_s }.map { |op| op.to_s }.join(" #{slug.to_s.upcase} ")})"
end

#union(other) ⇒ OrOperation Also known as: |, +

Return the union with another operand



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# File 'lib/dm-core/query/conditions/operation.rb', line 231

def union(other)
  Operation.new(:or, dup, other.dup).minimize
end

#valid? ⇒ Boolean

Test if the operation is valid



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# File 'lib/dm-core/query/conditions/operation.rb', line 189

def valid?
  any? && all? { |op| valid_operand?(op) }
end