Module: Axiom::Algebra::Restriction::Methods

Defined in:

lib/axiom/algebra/restriction.rb

Instance Method Summary

• #restrict(*args) {|context| ... } ⇒ Restriction

  Return a relation with restricted tuples.

Instance Method Details

#restrict(*args) {|context| ... } ⇒ Restriction

Return a relation with restricted tuples

Examples:

restriction with a predicate

restriction = relation.restrict(predicate)

restriction using a block

restriction = relation.restrict do |context|
  context.a.eq('other').and(context.b.gte(42))
end

restriction using a Hash

restriction = relation.restrict(id: 1)

restriction using an Array

restriction = relation.restrict([[:id, 1]])

Parameters:

• args (Array) —

  optional arguments

Yields:

• (context) —

  optional block to restrict the tuples with

Yield Parameters:

• context (Evaluator::Context) —

  the context to evaluate the restriction with

Yield Returns:

• (Function, #call) —

  predicate to restrict the tuples with

Returns:

• (Restriction)

# File 'lib/axiom/algebra/restriction.rb', line 124

def restrict(*args, &block)
  Restriction.new(self, coerce_to_predicate(*args, &block))
end