acc: refactor strip() routines

* src/tgba/acc.cc, src/tgba/acc.hh: Move the strip() routine from
acc_cond into acc_cond::mark_t, and the strip() routine from
cleanacc.cc into acc_cond::acc_code.  Introduce helper functions
to create inf()/fin()/t()/f() at the acc_code level.
* src/tgbaalgos/cleanacc.cc: Simplify, using the strip() function
from acc_code.
* src/tgbaalgos/mask.cc (mask_acc_sets): Use the strip() function
from acc_code so that it work on non-Buchi acceptance.
* src/tgbatest/maskacc.test: Add a test for the latter change.
* src/tgbaalgos/sccfilter.cc, src/tgbatest/acc.cc: Adjust the
use mark_t::strip().

src/tgbatest/acc.cc

@@ -103,7 +103,7 @@ int main()
   for (auto& v: s)
     {
       check(ac, v);
-      check(ac, ac.strip(v, u));
+      check(ac, v.strip(u));
     }
 
 

src/tgbatest/maskacc.test

@@ -111,6 +111,51 @@ diff output expect3
 run 0 ../../bin/autfilt --mask-acc=0 --mask-acc=1 input1 -H >output
 diff output expect3
 
+cat >input4 <<EOF
+HOA: v1
+States: 4
+Start: 0
+AP: 2 "a" "b"
+acc-name: generalized-Buchi 2
+Acceptance: 3 Inf(1)|Fin(0)
+properties: trans-labels explicit-labels trans-acc
+--BODY--
+State: 0
+[0] 1 {0}
+[1] 2 {1}
+State: 1
+[0] 2
+[0] 3 {1}
+State: 2
+[1] 1
+[1] 3 {0}
+State: 3
+[0] 3 {0 1}
+--END--
+EOF
+
+cat >expect4 <<EOF
+HOA: v1
+States: 4
+Start: 0
+AP: 2 "a" "b"
+Acceptance: 2 Inf(0)
+properties: trans-labels explicit-labels trans-acc
+--BODY--
+State: 0
+[1] 1 {0}
+State: 1
+[1] 2
+State: 2
+[0] 1
+[0] 3 {0}
+State: 3
+--END--
+EOF
+
+run 0 ../../bin/autfilt --mask-acc=0 input4 -H >output
+diff output expect4
+
 # Errors
 run 2 ../../bin/autfilt --mask-acc=a3 input1
 run 2 ../../bin/autfilt --mask-acc=3-2 input1