nitcc: add Automaton::clear_tag

Signed-off-by: Jean Privat <jean@pryen.org>

diff --git a/contrib/nitcc/src/autom.nit b/contrib/nitcc/src/autom.nit
index 9c813be..ee7f42d 100644 (file)
--- a/contrib/nitcc/src/autom.nit
+++ b/contrib/nitcc/src/autom.nit
@@ -61,6 +61,21 @@ class Automaton
                else
                        retrotags[t].add s
                end
+
+               assert tags[s].has(t)
+               assert retrotags[t].has(s)
+       end
+
+       # Remove all occurences of a tag in an automaton
+       fun clear_tag(t: Token)
+       do
+               if not retrotags.has_key(t) then return
+               for s in retrotags[t] do
+                       if not tags.has_key(s) then continue
+                       tags[s].remove(t)
+                       if tags[s].is_empty then tags.keys.remove(s)
+               end
+               retrotags.keys.remove(t)
        end
 
        # Remove tokens from conflicting state according the the inclusion of language