Comment out encoding of refs and pids for the time being

Also comment out the corresponding tests until we decide what
is the proper way to handle these terms in the solver.

This fixes the SOLVER ERROR crash reported in #120.

src/cuter_serial.erl

@@ -185,12 +185,17 @@ encode_term(T, Seen) when is_tuple(T) ->
   Ts = tuple_to_list(T),
   Subterms = [encode_maybe_shared_term(X, Seen) || X <- Ts],
   #'ErlangTerm'{type='TUPLE', subterms=Subterms};
-%% pid
-encode_term(Pid, _Seen) when is_pid(Pid) ->
-  #'ErlangTerm'{type='PID', value=pid_to_list(Pid)};
-%% reference
-encode_term(Ref, _Seen) when is_reference(Ref) ->
-  #'ErlangTerm'{type='REFERENCE', value=erlang:ref_to_list(Ref)};
+%%%
+%%% TODO: Uncomment out these clauses when it is decided how to
+%%% properly handle pids and refs.  Also, make sure that the
+%%% corresponding unit tests are re-enabled.
+%%%
+%% %% pid
+%% encode_term(Pid, _Seen) when is_pid(Pid) ->
+%%   #'ErlangTerm'{type='PID', value=pid_to_list(Pid)};
+%% %% reference
+%% encode_term(Ref, _Seen) when is_reference(Ref) ->
+%%   #'ErlangTerm'{type='REFERENCE', value=erlang:ref_to_list(Ref)};
 %% bitstring & binary
 encode_term(Ref, _Seen) when is_bitstring(Ref) ->
   Bits = encode_bitstring(Ref),
@@ -208,7 +213,7 @@ encode_term(M, Seen) when is_map(M) ->
 encode_term(Term, _Seen) ->
   case cuter_lib:is_lambda(Term) of
     %% fun (cuter_lib:lambda())
-    %% TODO Use the same Seen set.
+    %% TODO: Use the same Seen set.
     true ->
       Points = cuter_lib:lambda_kvs(Term),
       Otherwise = cuter_lib:lambda_default(Term),

test/utest/src/cuter_serial_tests.erl

@@ -38,13 +38,13 @@ encdec_test_() ->
       {"Simple", {1,2,3}},
       {"With shared subterms", {1,2,{1,2},{3,1,2},{1,2}}}
     ]},
-    {"PIDs", [
-      {"Self", self()},
-      {"Group leader", erlang:group_leader()}
-    ]},
-    {"References", [
-      {"Make reference", erlang:make_ref()}
-    ]},
+    %% {"PIDs", [
+    %%   {"Self", self()},
+    %%   {"Group leader", erlang:group_leader()}
+    %% ]},
+    %% {"References", [
+    %%   {"Make reference", erlang:make_ref()}
+    %% ]},
     {"Bitstrings", [
       {"binary", <<42>>},
       {"bitstring", <<42:42>>}
@@ -74,7 +74,7 @@ encode_decode(Terms) ->
   [{Descr, ?_assertEqual(maybe(T), Dec(Enc(T)))} || {Descr, T} <- Terms].
 
 %% Special case for reference().
-maybe(Rf) when is_reference(Rf) -> erlang:ref_to_list(Rf);
+%% maybe(Rf) when is_reference(Rf) -> erlang:ref_to_list(Rf);
 maybe(T) -> T.
 
 %% Serializing unsupported terms tests.
@@ -94,7 +94,7 @@ enc_fail_test_() ->
 encdec_cmd_test_() ->
   Cs = [
     {"I", {'OP_PARAMS', [cuter_symbolic:fresh_symbolic_var(), cuter_symbolic:fresh_symbolic_var()]}},
-    {"II", {'OP_MATCH_EQUAL_FALSE', [cuter_symbolic:fresh_symbolic_var(), erlang:make_ref()]}},
+    {"II", {'OP_MATCH_EQUAL_FALSE', [cuter_symbolic:fresh_symbolic_var()]}},	%% , erlang:make_ref()]}},
     {"III", {'OP_PARAMS', [cuter_symbolic:fresh_symbolic_var(), 42]}},
     {"IV", {'OP_CONS', [cuter_symbolic:fresh_symbolic_var(), cuter_symbolic:fresh_symbolic_var(), [<<"false">>]]}}
   ],