class RuboCop::AST::NodePattern::Compiler::Binding
Holds the list of bound variable names
def bind(name)
-
(String)
- bound variable name
def bind(name) var = @bound.fetch(name) do yield n = @bound[name] = "unify_#{name.gsub('-', '__')}" n end if var == :forbidden_unification raise Invalid, "Wildcard #{name} was first seen in a subset of a" \ " union and can't be used outside that union" end var end
def forbid(names)
def forbid(names) names.each do |name| @bound[name] = :forbidden_unification end end
def initialize
def initialize @bound = {} end
def union_bind(enum)
def union_bind(enum) # We need to reset @bound before each branch is processed. # Moreover we need to keep track of newly encountered wildcards. # Var `newly_bound_intersection` will hold those that are encountered # in all branches; these are not a problem. # Var `partially_bound` will hold those encountered in only a subset # of the branches; these can't be used outside of the union. return to_enum __method__, enum unless block_given? newly_bound_intersection = nil partially_bound = [] bound_before = @bound.dup result = enum.each do |e| @bound = bound_before.dup if newly_bound_intersection yield e newly_bound = @bound.keys - bound_before.keys if newly_bound_intersection.nil? # First iteration newly_bound_intersection = newly_bound else union = newly_bound_intersection | newly_bound newly_bound_intersection &= newly_bound partially_bound |= union - newly_bound_intersection end end # At this point, all members of `newly_bound_intersection` can be used # for unification outside of the union, but partially_bound may not forbid(partially_bound) result end