diff options
Diffstat (limited to 'actionpack/lib/action_dispatch/journey/nfa/simulator.rb')
-rw-r--r-- | actionpack/lib/action_dispatch/journey/nfa/simulator.rb | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/journey/nfa/simulator.rb b/actionpack/lib/action_dispatch/journey/nfa/simulator.rb new file mode 100644 index 0000000000..b23270db3c --- /dev/null +++ b/actionpack/lib/action_dispatch/journey/nfa/simulator.rb @@ -0,0 +1,47 @@ +require 'strscan' + +module ActionDispatch + module Journey # :nodoc: + module NFA # :nodoc: + class MatchData # :nodoc: + attr_reader :memos + + def initialize(memos) + @memos = memos + end + end + + class Simulator # :nodoc: + attr_reader :tt + + def initialize(transition_table) + @tt = transition_table + end + + def simulate(string) + input = StringScanner.new(string) + state = tt.eclosure(0) + until input.eos? + sym = input.scan(%r([/.?]|[^/.?]+)) + + # FIXME: tt.eclosure is not needed for the GTG + state = tt.eclosure(tt.move(state, sym)) + end + + acceptance_states = state.find_all { |s| + tt.accepting?(tt.eclosure(s).sort.last) + } + + return if acceptance_states.empty? + + memos = acceptance_states.flat_map { |x| tt.memo(x) }.compact + + MatchData.new(memos) + end + + alias :=~ :simulate + alias :match :simulate + end + end + end +end |