bin: add support for SPOT_DEFAULT_FORMAT

* bin/common_aoutput.cc, bin/common_aoutput.hh, bin/common_setup.cc:
Implement it.
* NEWS, bin/man/spot-x.x: Document it.
* tests/core/readsave.test: Test it.

NEWS

@@ -6,6 +6,10 @@ New in spot 1.99.6a (not yet released)
     randaut's short option for specifying edge-density used to be -d:
     it has been renamed to -e.
 
+  * The SPOT_DEFAULT_FORMAT environment variable can be set to 'dot'
+    or 'hoa' to force a default output format for automata.  Options
+    may also be added, as in SPOT_DEFAULT_FORMAT='hoa=iv'.
+
   * autfilt has a new option: --is-inherently-weak.
 
   Library:

bin/common_aoutput.cc

@@ -36,10 +36,7 @@
 #include <spot/twaalgos/strength.hh>
 
 automaton_format_t automaton_format = Dot;
-static const char* opt_dot = nullptr;
+static const char* automaton_format_opt = nullptr;
-static const char* opt_never = nullptr;
-static const char* hoa_opt = nullptr;
-static const char* opt_lbtt = nullptr;
 const char* opt_name = nullptr;
 static const char* opt_output = nullptr;
 static const char* stats = "";
@@ -230,11 +227,11 @@ int parse_opt_aoutput(int key, char* arg, struct argp_state*)
       break;
     case 'd':
       automaton_format = Dot;
-      opt_dot = arg;
+      automaton_format_opt = arg;
       break;
     case 'H':
       automaton_format = Hoa;
-      hoa_opt = arg;
+      automaton_format_opt = arg;
       break;
     case 'o':
       opt_output = arg;
@@ -246,8 +243,7 @@ int parse_opt_aoutput(int key, char* arg, struct argp_state*)
       automaton_format = Spin;
       if (type != spot::postprocessor::Monitor)
 	type = spot::postprocessor::BA;
-      if (arg)
+      automaton_format_opt = arg;
-	opt_never = arg;
       break;
     case OPT_CHECK:
       automaton_format = Hoa;
@@ -258,7 +254,7 @@ int parse_opt_aoutput(int key, char* arg, struct argp_state*)
       break;
     case OPT_LBTT:
       automaton_format = Lbtt;
-      opt_lbtt = arg;
+      automaton_format_opt = arg;
       // This test could be removed when more options are added,
       // because print_lbtt will raise an exception anyway.  The
       // error message is slightly better in the current way.
@@ -280,7 +276,30 @@ int parse_opt_aoutput(int key, char* arg, struct argp_state*)
   return 0;
 }
 
-
+void setup_default_output_format()
+{
+  if (auto val = getenv("SPOT_DEFAULT_FORMAT"))
+    {
+      static char const *const args[] =
+	{
+	  "dot", "hoa", "hoaf", nullptr
+	};
+      static automaton_format_t const format[] =
+	{
+	  Dot, Hoa, Hoa
+	};
+      auto eq = strchr(val, '=');
+      if (eq)
+	{
+	  val = strndup(val, eq - val);
+	  automaton_format_opt = eq + 1;
+	}
+      ARGMATCH_VERIFY(args, format);
+      automaton_format = XARGMATCH("SPOT_DEFAULT_FORMAT", val, args, format);
+      if (eq)
+	free(val);
+    }
+}
 
 automaton_printer::automaton_printer(stat_style input)
   : statistics(std::cout, stats, input),
@@ -340,16 +359,16 @@ automaton_printer::print(const spot::twa_graph_ptr& aut,
       // Do not output anything.
       break;
     case Dot:
-      spot::print_dot(*out, aut, opt_dot);
+      spot::print_dot(*out, aut, automaton_format_opt);
       break;
     case Lbtt:
-      spot::print_lbtt(*out, aut, opt_lbtt);
+      spot::print_lbtt(*out, aut, automaton_format_opt);
       break;
     case Hoa:
-      spot::print_hoa(*out, aut, hoa_opt) << '\n';
+      spot::print_hoa(*out, aut, automaton_format_opt) << '\n';
       break;
     case Spin:
-      spot::print_never_claim(*out, aut, opt_never);
+      spot::print_never_claim(*out, aut, automaton_format_opt);
       break;
     case Stats:
       statistics.set_output(*out);

bin/common_aoutput.hh

@@ -1,6 +1,6 @@
 // -*- coding: utf-8 -*-
-// Copyright (C) 2014, 2015 Laboratoire de Recherche et Développement
+// Copyright (C) 2014, 2015, 2016 Laboratoire de Recherche et
-// de l'Epita (LRDE).
+// Développement de l'Epita (LRDE).
 //
 // This file is part of Spot, a model checking library.
 //
@@ -233,3 +233,5 @@ public:
 
   void add_stat(char c, const spot::printable* p);
 };
+
+void setup_default_output_format();

bin/common_setup.cc

@@ -18,6 +18,8 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 #include "common_setup.hh"
+#include "common_aoutput.hh"
+
 #include "argp.h"
 #include <cstdlib>
 #include <iostream>
@@ -40,6 +42,7 @@ This is free software: you are free to change and redistribute it.\n\
 There is NO WARRANTY, to the extent permitted by law.\n", stream);
 }
 
+
 #ifdef HAVE_SIGACTION
 static void sig_handler(int sig)
 {
@@ -81,6 +84,7 @@ setup(char** argv)
 
   std::ios_base::sync_with_stdio(false);
 
+  setup_default_output_format();
   setup_sig_handler();
 }
 

bin/man/spot-x.x

@@ -1,5 +1,5 @@
 [NAME]
-spot-x \- Common fine-tuning options.
+spot-x \- Common fine-tuning options and environment variables.
 
 [SYNOPSIS]
 .B \-\-extra-options STRING
@@ -11,14 +11,41 @@ spot-x \- Common fine-tuning options.
 
 [ENVIRONMENT VARIABLES]
 
+.TP
+\fBSPOT_DEFAULT_FORMAT\fR
+Set to a value of \fBdot\fR or \fBhoa\fR to override the default
+format used to output automata.  Up to Spot 1.9.6 the default output
+format for automata used to be \fBdot\fR.  Starting with Spot 1.9.7,
+the default output format switched to \fBhoa\fR as it is more
+convenient when chaining tools in a pipe.  Set this variable to
+\fBdot\fR to get the old behavior.  Additional options may be
+passed to the printer by suffixing the output format with
+\fB=\fR and the options.  For instance running
+.in +4n
+.nf
+.ft C
+% SPOT_DEFAULT_OUTPUT=dot=bar autfilt ...
+.fi
+.in -4n
+is the same as running
+.in +4n
+.nf
+.ft C
+% autfilt --dot=bar ...
+.fi
+.in -4n
+but the use of the environment variable makes more sense if you set
+it up once for many commands.
+
 .TP
 \fBSPOT_DOTDEFAULT\fR
 Whenever the \f(CW--dot\fR option is used without argument (even
-implicitely), the contents of this variable is used as default
+implicitely via \fBSPOT_DEFAULT_FORMAT\fR), the contents of this
-argument.  If you have some default setting in \fBSPOT_DOTDEFAULT\fR
+variable is used as default argument.  If you have some default
-but want to alter them temporarily for one call, use
+setting in \fBSPOT_DOTDEFAULT\fR but want to alter them temporarily
-\f(CW--dot=.yyy\fR: the dot character will be replaced by the contents
+for one call, use \f(CW--dot=.yyy\fR: the dot character will be
-of the \f(CWSPOT_DOTDEFAULT\fR environment variable.
+replaced by the contents of the \f(CWSPOT_DOTDEFAULT\fR environment
+variable.
 
 .TP
 \fBSPOT_DOTEXTRA\fR

tests/core/readsave.test

@@ -306,7 +306,10 @@ State: 3 "s3"
 EOF
 
 autfilt -H input |
-    SPOT_DOTDEFAULT=vcsn SPOT_DOTEXTRA='/* hello world */' autfilt >output
+    SPOT_DEFAULT_FORMAT=dot \
+    SPOT_DOTDEFAULT=vcsn \
+    SPOT_DOTEXTRA='/* hello world */' \
+    autfilt >output
 
 cat >expected <<EOF
 digraph G {
@@ -340,7 +343,8 @@ diff output expected
 test 1 = `autfilt -H input --complete | autfilt --is-complete --count`
 
 
-ltl2tgba --dot=a 'GFa & GFb' >output
+# The SPOT_DEFAULT_FORMAT envvar should be ignored if --dot is given.
+SPOT_DEFAULT_FORMAT=hoa ltl2tgba --dot=a 'GFa & GFb' >output
 cat output
 cat >expected <<EOF
 digraph G {
@@ -607,7 +611,7 @@ diff output1 output1b
 # Here is the scenario where the undefined states are actually states
 # we wanted to remove.  So we tell autfilt to fix the automaton using
 # --remove-dead-states
-autfilt -H --remove-dead input >output2 && exit 1
+SPOT_DEFAULT_FORMAT=hoa autfilt --remove-dead input >output2 && exit 1
 
 cat >expect2 <<EOF
 HOA: v1
@@ -629,7 +633,7 @@ EOF
 
 diff output2 expect2
 
-autfilt -Hk expect2 >output2b
+SPOT_DEFAULT_FORMAT=hoa=k autfilt expect2 >output2b
 
 cat >expect2b <<EOF
 HOA: v1