require 'action_dispatch/journey/nfa/transition_table' require 'action_dispatch/journey/gtg/transition_table' module ActionDispatch module Journey # :nodoc: module NFA # :nodoc: class Visitor < Visitors::Visitor # :nodoc: def initialize(tt) @tt = tt @i = -1 end def visit_CAT(node) left = visit(node.left) right = visit(node.right) @tt.merge(left.last, right.first) [left.first, right.last] end def visit_GROUP(node) from = @i += 1 left = visit(node.left) to = @i += 1 @tt.accepting = to @tt[from, left.first] = nil @tt[left.last, to] = nil @tt[from, to] = nil [from, to] end def visit_OR(node) from = @i += 1 children = node.children.map { |c| visit(c) } to = @i += 1 children.each do |child| @tt[from, child.first] = nil @tt[child.last, to] = nil end @tt.accepting = to [from, to] end def terminal(node) from_i = @i += 1 # new state to_i = @i += 1 # new state @tt[from_i, to_i] = node @tt.accepting = to_i @tt.add_memo(to_i, node.memo) [from_i, to_i] end end class Builder # :nodoc: def initialize(ast) @ast = ast end def transition_table tt = TransitionTable.new Visitor.new(tt).accept(@ast) tt end end end end end