ltlfilt: add a --save-part-file option

* bin/ltlfilt.cc: Add support for --save-part-file.
* NEWS, doc/org/ltlfilt.org: Mention it.
* tests/core/ltlfilt.test: Test it.

NEWS

@@ -37,6 +37,10 @@ New in spot 2.12.2.dev  (not yet released)
     be inferred from their name.  (This suspports a --part-file option
     as well.)
 
+  - ltlfilt learned --save-part-file[=FILENAME] option that can be
+    used to create partition files suitable for many synthesis tools
+    (including ltlsynt).
+
   - genltl learned --lily-patterns to generate the example LTL
     synthesis specifications from Lily 1.0.2.  Those come with input
     and output atomic proposition rewriten in the form "iNN" or "oNN",

bin/ltlfilt.cc

@@ -103,6 +103,7 @@ enum {
   OPT_REMOVE_WM,
   OPT_REMOVE_X,
   OPT_SAFETY,
+  OPT_SAVE_PART_FILE,
   OPT_SIGMA2,
   OPT_SIZE,
   OPT_SIZE_MAX,
@@ -184,13 +185,18 @@ static const argp_option options[] =
       " proposition", 0 },
     { "ins", OPT_INS, "PROPS", 0,
       "comma-separated list of input atomic propositions to use with "
-      "--relabel=io, interpreted as a regex if enclosed in slashes", 0 },
+      "--relabel=io or --save-part-file, interpreted as a regex if enclosed "
+      "in slashes", 0 },
     { "outs", OPT_OUTS, "PROPS", 0,
       "comma-separated list of output atomic propositions to use with "
-      "--relabel=io, interpreted as a regex if enclosed in slashes", 0 },
+      "--relabel=io or --save-part-file, interpreted as a regex if "
+      "enclosed in slashes", 0 },
     { "part-file", OPT_PART_FILE, "FILENAME", 0,
       "file containing the partition of atomic propositions to use with "
       "--relabel=io", 0 },
+    { "save-part-file", OPT_SAVE_PART_FILE, "FILENAME", OPTION_ARG_OPTIONAL,
+      "file containing the partition of atomic propositions, "
+      "readable by --part-file", 0 },
     DECLARE_OPT_R,
     LEVEL_DOC(4),
     /**************************************************/
@@ -377,6 +383,7 @@ static struct opt_t
 {
   spot::bdd_dict_ptr dict = spot::make_bdd_dict();
   spot::exclusive_ap excl_ap;
+  std::unique_ptr<output_file> output_part = nullptr;
   std::unique_ptr<output_file> output_define = nullptr;
   std::unique_ptr<output_file> output_sonf = nullptr;
   spot::formula implied_by = nullptr;
@@ -596,6 +603,9 @@ parse_opt(int key, char* arg, struct argp_state*)
     case OPT_SAFETY:
       safety = obligation = true;
       break;
+    case OPT_SAVE_PART_FILE:
+      opt->output_part.reset(new output_file(arg ? arg : "-"));
+      break;
     case OPT_SIZE:
       size = parse_range(arg, 0, std::numeric_limits<int>::max());
       break;
@@ -954,6 +964,40 @@ namespace
                                oldname, filename,
                                std::to_string(linenum).c_str()) << ")\n";
             }
+          if (opt->output_part
+              && output_format != count_output
+              && output_format != quiet_output)
+            {
+              std::vector<spot::formula> ins;
+              std::vector<spot::formula> outs;
+              spot::atomic_prop_set* s = atomic_prop_collect(f);
+              for (spot::formula ap: *s)
+                {
+                  spot::formula apo = ap;
+                  if (auto it = relmap.find(ap); it != relmap.end())
+                    apo = it->second;
+                  if (is_output(apo.ap_name(), filename, linenum))
+                    outs.push_back(ap);
+                  else
+                    ins.push_back(ap);
+                }
+              delete s;
+              auto& os = opt->output_part->ostream();
+              if (!ins.empty())
+                {
+                  os << ".inputs";
+                  for (const auto& ap: ins)
+                    os << ' ' << str_psl(ap);
+                  os << '\n';
+                }
+              if (!outs.empty())
+                {
+                  os << ".outputs";
+                  for (const auto& ap: outs)
+                    os << ' ' << str_psl(ap);
+                  os << '\n';
+                }
+            }
           one_match = true;
           output_formula_checked(f, &timer, filename, linenum,
                                  match_count, prefix, suffix);
@@ -982,7 +1026,7 @@ main(int argc, char** argv)
       if (jobs.empty())
         jobs.emplace_back("-", job_type::LTL_FILENAME);
 
-      if (relabeling == IOApRelabeling)
+      if (relabeling == IOApRelabeling || opt->output_part)
         process_io_options();
 
       if (boolean_to_isop && simplification_level == 0)

doc/org/ltlfilt.org

@@ -301,14 +301,18 @@ ltldo ltl3ba -f '"proc@loc1" U "proc@loc2"' --spin
 This case also relabels the formula before calling =ltl3ba=, and it
 then renames all the atomic propositions in the output.
 
+An example showing how to use the =--from-ltlf= option is on [[file:tut12.org][a
+separate page]].
+
+* I/O-partitioned formulas
 
 A special relabeling mode related to LTL synthesis is =--relabel=io=.
 In LTL synthesis (see [[file:ltlsynt.org][=ltlsynt=]]), atomic propositions are partitioned
 in two sets: the /input/ propositions represent choices from the
-environment, while /output/ proposition represent choices by the
+environment, while /output/ propositions represent choices by the
 controller to be synthesized.  For instance
 =G(req -> Fack) & G(go -> Fgrant)=
-represents could be a specification where =req= and =go= are inputs,
+could be a specification where =req= and =go= are inputs,
 while =ack= and =grant= are outputs.   Tool such as =ltlsynt= need
 to be told using options such as =--ins= or =--outs= which atomic
 propositions are input or output.  Often these atomic propositions
@@ -331,8 +335,24 @@ when these two options are missing the convention is that anything
 starting with =i= is an input, and anything starting with =o= is an
 output.
 
-An example showing how to use the =--from-ltlf= option is on [[file:tut12.org][a
-separate page]].
+=ltlfilt= can also be instructed to create a partition file (usually
+named =*.part=) that can be used by synthesis tools.
+
+#+BEGIN_SRC sh
+ltlfilt -f 'G(req -> Fack) & G(go -> Fgrant)' --relabel=io \
+    --ins=req,go --save-part=out.part
+#+END_SRC
+#+RESULTS:
+: G(i1 -> Fo0) & G(i0 -> Fo1)
+
+In addition to the relabeling, this also created a file =out.part=
+containing the following:
+#+BEGIN_SRC sh :exports results
+cat out.part
+#+END_SRC
+#+RESULTS:
+: .inputs i0 i1
+: .outputs o0 o1
 
 * Filtering
 

tests/core/ltlfilt.test

@@ -872,3 +872,19 @@ diff expected out
 # would stick to the rest of the file unless overridden.
 run 2 ltlfilt -Ffile/1 -Ffile
 :
+
+
+run 0 ltlfilt -f 'i1 U o2 U i3' --save-part=p.part
+cat > exp.part<<EOF
+.inputs i1 i3
+.outputs o2
+EOF
+diff exp.part p.part
+
+run 0 ltlfilt -f 'a U b U c' --ins=a --relabel=io --save-part >out
+cat > exp<<EOF
+.inputs i0
+.outputs o0 o1
+i0 U (o0 U o1)
+EOF
+diff exp out