Mark STATES as a private constant

lib/prism/lex_compat.rb

@@ -639,7 +639,7 @@ def result
 
         event = RIPPER.fetch(token.type)
         value = token.value
-        lex_state = Translation::Ripper::Lexer::State.cached(lex_state)
+        lex_state = Translation::Ripper::Lexer::State[lex_state]
 
         token =
           case event
@@ -691,7 +691,7 @@ def result
                   counter += { on_embexpr_beg: -1, on_embexpr_end: 1 }[current_event] || 0
                 end
 
-                Translation::Ripper::Lexer::State.cached(result_value[current_index][1])
+                Translation::Ripper::Lexer::State[result_value[current_index][1]]
               else
                 previous_state
               end
@@ -828,7 +828,7 @@ def result
     def add_on_sp_tokens(tokens, source, data_loc, bom, eof_token)
       new_tokens = []
 
-      prev_token_state = Translation::Ripper::Lexer::State.cached(Translation::Ripper::EXPR_BEG)
+      prev_token_state = Translation::Ripper::Lexer::State[Translation::Ripper::EXPR_BEG]
       prev_token_end = bom ? 3 : 0
 
       tokens.each do |token|

lib/prism/translation/ripper/lexer.rb

@@ -9,7 +9,6 @@ class Ripper
       class Lexer < Ripper # :nodoc:
         # :stopdoc:
         class State
-
           attr_reader :to_int, :to_s
 
           def initialize(i)
@@ -39,10 +38,12 @@ def allbits?(i) to_int.allbits?(i) end
           def anybits?(i) to_int.anybits?(i) end
           def nobits?(i) to_int.nobits?(i) end
 
-          # Instances are frozen and there are only a handful of them so we cache them here.
-          STATES = Hash.new { |h,k| h[k] = State.new(k) }
+          # Instances are frozen and there are only a handful of them so we
+          # cache them here.
+          STATES = Hash.new { |hash, key| hash[key] = State.new(key) }
+          private_constant :STATES
 
-          def self.cached(i)
+          def self.[](i)
             STATES[i]
           end
         end
@@ -54,7 +55,7 @@ def initialize(pos, event, tok, state, message = nil)
             @pos = pos
             @event = event
             @tok = tok
-            @state = State.cached(state)
+            @state = State[state]
             @message = message
           end