nitcc: add `Automaton::assert_valid`

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

diff --git a/contrib/nitcc/src/autom.nit b/contrib/nitcc/src/autom.nit
index 3ca56bc..dd57b52 100644 (file)
--- a/contrib/nitcc/src/autom.nit
+++ b/contrib/nitcc/src/autom.nit
@@ -373,6 +373,8 @@ class Automaton
        # REQUIRE: self is a DFA
        fun to_minimal_dfa: Automaton
        do
+               assert_valid
+
                trim
 
                # Graph of known distinct states.
@@ -449,6 +451,21 @@ class Automaton
                return to_dfa
        end
 
+       # Assert that `self` is a valid automaton or abort
+       fun assert_valid
+       do
+               assert states.has(start)
+               assert states.has_all(accept)
+               for s in states do
+                       for t in s.outs do assert states.has(t.to)
+                       for t in s.ins do assert states.has(t.from)
+               end
+               assert states.has_all(tags.keys)
+               for t, ss in retrotags do
+                       assert states.has_all(ss)
+               end
+       end
+
        # Produce a graphvis file for the automaton
        fun to_dot(filepath: String)
        do
@@ -514,6 +531,8 @@ class Automaton
        # note: the DFA is not minimized.
        fun to_dfa: Automaton
        do
+               assert_valid
+
                trim
 
                var dfa = new Automaton.empty