Module: Predicate::Or

Includes:
NadicBool
Defined in:
lib/predicate/nodes/or.rb

Constant Summary

Constants included from Expr

Expr::OP_NEGATIONS

Instance Method Summary collapse

Methods included from NadicBool

#free_variables, #priority

Methods included from Expr

#!, #&, #and_split, #assert!, #attr_split, #bind, #constant_variables, #constants, #contradiction?, #dyadic_priority, #identifier?, #literal?, #opaque?, #qualify, #rename, #sexpr, #tautology?, #to_postgres, #to_s, #to_sequel, #unqualify, #|

Methods included from Factory

#_factor_predicate, #and, #comp, #contradiction, #empty, #from_hash, #h, #has_size, #identifier, #in, #literal, #match, #native, #not, #opaque, #or, #pg_array_empty, #pg_array_literal, #pg_array_overlaps, #placeholder, #qualified_identifier, #sexpr, #tautology, #var, #vars

Instance Method Details

#evaluate(tuple) ⇒ Object 



9
10
11
 
# File 'lib/predicate/nodes/or.rb', line 9

def evaluate(tuple)
  sexpr_body.any?{|op| op.evaluate(tuple) }
end

#operator_symbol ⇒ Object 



5
6
7
 
# File 'lib/predicate/nodes/or.rb', line 5

def operator_symbol
  :'||'
end

#to_hash ⇒ Object

A disjunction can be represented as a { attr => [values] } hash only when every operand constrains the same single attribute to a literal or a set of literals, e.g. x == 1 OR x == 2 OR x IN [3, 4]. Operands are folded together into an IN-style hash. As soon as an operand touches another attribute, or cannot itself be represented as a hash, the whole disjunction is not representable and an ArgumentError is raised (as for any other non-representable predicate).



20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
 
# File 'lib/predicate/nodes/or.rb', line 20

def to_hash
  merged = sexpr_body.inject(nil) do |acc, term|
    hash = term.to_hash
    return super unless hash.size == 1

    attr, value = hash.first
    values = value.is_a?(Array) ? value : [value]

    if acc.nil?
      [attr, values.dup]
    elsif acc.first == attr
      [attr, acc.last + values]
    else
      return super
    end
  end

  return super if merged.nil?
  { merged.first => merged.last.uniq }
end

#to_hashes ⇒ Object 



41
42
43
 
# File 'lib/predicate/nodes/or.rb', line 41

def to_hashes
  [ to_hash, {} ]
end