bin: add shorthands for ltlcross and ltldo

* src/bin/common_trans.cc: Implement shorthands.
* doc/org/ltlcross.org, doc/org/ltldo.org: Document them.
* src/tgbatest/ltldo2.test: Quick test.
* NEWS: Mention it.

NEWS

@@ -37,6 +37,12 @@ New in spot 1.99a (not yet released)
       now.  The short '-n NUM' option is now the same as the new
       --max-count=N option, for consistency with other tools.
 
+    - ltlcross (and ltldo) have a list of hard-coded shorthands
+      for some existing tools.  So for instance running
+      'ltlcross spin ...' is the same as running
+      'ltlcross "spin -f %s>%N" ...'.   This feature is much
+      more useful for ltldo.
+
     - There is a parser for the HOA format
       (http://adl.github.io/hoaf/) available as a
       spot::hoa_stream_parser object or spot::hoa_parse() function.

doc/org/ltlcross.org

@@ -149,6 +149,35 @@ tools:
     so we have to rename =%D.dst= as =%D= so that =ltlcross= can find the file)
   - '=ltl3dra -f %s >%D='
 
+To simplify the use of some of the above tools, a set of predefined
+shorthands are available.  Those can be listed with the
+=--list-shorthands= option.
+
+#+BEGIN_SRC sh :results verbatim :exports both
+ltlcross --list-shorthands
+#+END_SRC
+#+RESULTS:
+#+begin_example
+If a COMMANDFMT does not use any %-sequence, and starts with one of
+the following words, then the string on the right is appended.
+
+  lbt          <%L>%T
+  ltl2ba       -f %s>%N
+  ltl2dstar    %L %D
+  ltl2tgba     -H %f>%H
+  ltl3ba       -f %s>%N
+  ltl3dra      -f %f>%D
+  modella      %L %T
+  spin         -f %s>%N
+#+end_example
+
+What this implies is that running =ltlcross ltl2ba ltl3ba ...= is
+the same as running =ltlcross 'ltl2ba -f %s>%N' 'ltl3ba -f %s>%N' ...=
+
+Because only the prefix of the actual command is checked, you can
+still specify some options.  For instance =ltlcross 'ltl2tgba -D' ...=
+is short for =ltlcross 'ltl2tgba -D -H %F>%H' ...=
+
 * Getting statistics
 
 Detailed statistics about the result of each translation, and the

doc/org/ltldo.org

@@ -81,7 +81,7 @@ X[]!<>((a && ![]b) || (!a && []b)),4,10
 Using =ltldo= the above command can be reduced to this:
 
 #+BEGIN_SRC sh :results verbatim :exports both
-ltldo -F sample.ltl 'ltl3ba -f %s>%N' --stats='%f,%s,%t'
+ltldo 'ltl3ba -f %s>%N' -F sample.ltl --stats='%f,%s,%t'
 #+END_SRC
 #+RESULTS:
 #+begin_example
@@ -101,6 +101,27 @@ Note that the formulas look different in both cases, because in the
 =while= loop the formula printed has already been processed with
 =ltlfilt=, while =ltldo= emits the input string untouched.
 
+In fact, as we will discuss below, =ltl3ba= is a tool that =ltldo=
+already knows about, so there is a shorter way to run the above
+command:
+
+#+BEGIN_SRC sh :results verbatim :exports code
+ltldo ltl3ba -F sample.ltl --stats='%f,%s,%t'
+#+END_SRC
+#+RESULTS:
+#+begin_example
+1,1,1
+1 U a,2,4
+!(!((a U Gb) U b) U GFa),2,4
+(b <-> Xc) xor Fb,7,21
+FXb R (a R (1 U b)),6,28
+Ga,1,1
+G(!(c | (a & (a W Gb))) M Xa),1,0
+GF((b R !a) U (Xc M 1)),2,4
+G(Xb | Gc),3,11
+XG!F(a xor Gb),4,10
+#+end_example
+
 * Example: running =spin= and producing HOA
 
 Here is another example, where we use Spin to produce two automata in
@@ -142,6 +163,13 @@ State: 1 {0}
 --END--
 #+end_example
 
+Again, using the shorthands defined below, the previous command can be
+simplified to just this:
+
+#+BEGIN_SRC sh :results verbatim :exports code
+ltldo spin -f a -f GFa -H
+#+END_SRC
+
 * Syntax for specifying tools to call
 
 The syntax for specifying how a tool should be called is the same as
@@ -159,9 +187,10 @@ ltldo --help | sed -n '/character sequences:/,/^$/p' | sed '1d;$d'
 :   %N,%T,%D,%H                the automaton is output as a Never claim, or in
 :                              LBTT's, in LTL2DSTAR's, or in the HOA format
 
-Contrarily to =ltlcross=, it this not mandatory to specify an output filename
-using one of the sequence for that later lines.  For instance we could
-simply run a formula though =echo= to compare different output syntaxes:
+Contrarily to =ltlcross=, it this not mandatory to specify an output
+filename using one of the sequence for that last line.  For instance
+we could simply run a formula though =echo= to compare different
+output syntaxes:
 
 #+BEGIN_SRC sh :results verbatim :exports both
 ltldo -f 'p0 U p1' -f 'GFp0' 'echo %f, %s, %l, %w'
@@ -257,6 +286,66 @@ ltl3ba,4,7
 
 Much more readable!
 
+* Shorthands for existing tools
+
+There is a list of existing tools for which =ltldo= (and =ltlcross=)
+have built-in specifications.  This list can be printed using the
+=--list-shorthands= option:
+
+#+BEGIN_SRC sh :results verbatim :exports both
+ltldo --list-shorthands
+#+END_SRC
+#+RESULTS:
+#+begin_example
+If a COMMANDFMT does not use any %-sequence, and starts with one of
+the following words, then the string on the right is appended.
+
+  lbt          <%L>%T
+  ltl2ba       -f %s>%N
+  ltl2dstar    %L %D
+  ltl2tgba     -H %f>%H
+  ltl3ba       -f %s>%N
+  ltl3dra      -f %f>%D
+  modella      %L %T
+  spin         -f %s>%N
+#+end_example
+
+So for instance you can type just
+
+#+BEGIN_SRC sh :results verbatim :exports both
+ltldo ltl2ba -f a
+#+END_SRC
+
+to obtain a Dot output (this is the default output format for =ltldo=)
+for the neverclaim produced by =ltl2ba -f a=.
+
+#+RESULTS:
+: digraph G {
+:   rankdir=LR
+:   I [label="", style=invis, width=0]
+:   I -> 0
+:   0 [label="0", peripheries=2]
+:   0 -> 1 [label="a"]
+:   1 [label="1", peripheries=2]
+:   1 -> 1 [label="1"]
+: }
+
+The =ltl2ba= argument passed to =ltldo= was interpreted as if you had
+typed ={ltl2ba}ltl2ba -f %s>%N=.
+
+The shorthand is only used if it is the first word of an command
+string that does not use any =%= character.  This makes it possible to
+add options:
+
+#+BEGIN_SRC sh :results verbatim :exports both
+ltldo ltl3ba 'ltl3ba -H2' -f GFa --stats='%T, %s states, %e edges'
+#+END_SRC
+
+#+RESULTS:
+: ltl3ba, 2 states, 4 edges
+: ltl3ba -H2, 1 states, 2 edges
+
+
 * Transparent renaming
 
 Have you ever tried to use =spin=, =ltl2ba=, or =ltl3ba=, to translate
@@ -281,7 +370,7 @@ only atomic propositions starting with a lowercase letter.
 Running the same command through =ltldo= will work:
 
 #+BEGIN_SRC sh :results verbatim :exports both
-ltldo -t 'spin -f %s>%N' -f '[]!Error' -s
+ltldo spin -f '[]!Error' -s
 #+END_SRC
 #+RESULTS:
 : never {
@@ -291,6 +380,9 @@ ltldo -t 'spin -f %s>%N' -f '[]!Error' -s
 :   fi;
 : }
 
+(We need the =-s= option to obtain a never claim, instead of the
+default GraphViz output.)
+
 What happened is that =ltldo= renamed the atomic propositions in the
 formula before calling =spin=.  So =spin= actually received the
 formula =[]!p0=, produced a never claim using =p0=, and that never
@@ -311,7 +403,7 @@ automaton uses the atomic proposition =Error=, but its name contains a
 reference to =p0=.
 
 #+BEGIN_SRC sh :results verbatim :exports both
-ltldo 'ltl3ba -H -f %s>%H' -f '[]!Error' -H
+ltldo 'ltl3ba -H' -f '[]!Error' -H
 #+END_SRC
 #+RESULTS:
 #+begin_example
@@ -333,7 +425,7 @@ If this is a problem, you can always force a new name with the
 =--name= option:
 
 #+BEGIN_SRC sh :results verbatim :exports both
-ltldo 'ltl3ba -H -f %s>%H' -f '[]!Error' -H --name='BA for %f'
+ltldo 'ltl3ba -H' -f '[]!Error' -H --name='BA for %f'
 #+END_SRC
 
 #+RESULTS:

src/bin/common_trans.cc

@@ -24,6 +24,7 @@
 #include <unistd.h>
 #include <signal.h>
 #include <sys/wait.h>
+#include <iomanip>
 
 #include "error.h"
 
@@ -31,29 +32,81 @@
 #include "ltlvisit/lbt.hh"
 #include "common_conv.hh"
 
+// A set of tools for which we know the correct output
+static struct shorthands_t
+{
+  const char* prefix;
+  const char* suffix;
+}
+  shorthands[] = {
+    { "lbt", " <%L>%T" },
+    { "ltl2ba", " -f %s>%N" },
+    { "ltl2dstar", " %L %D"},
+    { "ltl2tgba", " -H %f>%H" },
+    { "ltl3ba", " -f %s>%N" },
+    { "ltl3dra", " -f %f>%D" },
+    { "modella", " %L %T" },
+    { "spin", " -f %s>%N" },
+  };
+
+void show_shorthands()
+{
+  std::cout
+    << ("If a COMMANDFMT does not use any %-sequence, and starts with one of\n"
+	"the following words, then the string on the right is appended.\n\n");
+  for (auto& s: shorthands)
+    std::cout << "  "
+	      << std::left << std::setw(12) << s.prefix
+	      << s.suffix << '\n';
+}
+
+
 translator_spec::translator_spec(const char* spec)
   : spec(spec), cmd(spec), name(spec)
 {
-  if (*cmd != '{')
-    return;
-
-  // Match the closing '}'
-  const char* pos = cmd;
-  unsigned count = 1;
-  while (*++pos)
+  if (*cmd == '{')
     {
-      if (*pos == '{')
-	++count;
-      else if (*pos == '}')
-	if (!--count)
-	  {
-	    name = strndup(cmd + 1, pos - cmd - 1);
-	    cmd = pos + 1;
-	    while (*cmd == ' ' || *cmd == '\t')
-	      ++cmd;
-	    break;
-	  }
+      // Match the closing '}'
+      const char* pos = cmd;
+      unsigned count = 1;
+      while (*++pos)
+	{
+	  if (*pos == '{')
+	    ++count;
+	  else if (*pos == '}')
+	    if (!--count)
+	      {
+		name = strndup(cmd + 1, pos - cmd - 1);
+		cmd = pos + 1;
+		while (*cmd == ' ' || *cmd == '\t')
+		  ++cmd;
+		break;
+	      }
+	}
+    }
+  // If we recognize a shorthand, add the suffixes.
+  bool allocated = false;
+  if (!strchr(cmd, '%'))
+    {
+      for (auto& p: shorthands)
+	{
+	  int n = strlen(p.prefix);
+	  if (strncmp(cmd, p.prefix, n) == 0 &&
+	      (cmd[n] == 0 || cmd[n] == ' '))
+	    {
+	      int m = strlen(p.suffix);
+	      int q = strlen(cmd);
+	      char* tmp = static_cast<char*>(malloc(q + m + 1));
+	      strcpy(tmp, cmd);
+	      strcpy(tmp + q, p.suffix);
+	      cmd = tmp;
+	      allocated = true;
+	      break;
+	    }
+	}
     }
+  if (!allocated)
+    cmd = strdup(cmd);
 }
 
 translator_spec::translator_spec(const translator_spec& other)
@@ -61,12 +114,16 @@ translator_spec::translator_spec(const translator_spec& other)
 {
   if (name != spec)
     name = strdup(name);
+  if (cmd != spec)
+    cmd = strdup(cmd);
 }
 
 translator_spec::~translator_spec()
 {
   if (name != spec)
     free(const_cast<char*>(name));
+  if (cmd != spec)
+    free(const_cast<char*>(cmd));
 }
 
 std::vector<translator_spec> translators;
@@ -326,6 +383,7 @@ exec_with_timeout(const char* cmd)
   return status;
 }
 
+#define OPT_LIST 1
 static const argp_option options[] =
 {
     /**************************************************/
@@ -333,6 +391,8 @@ static const argp_option options[] =
     { "translator", 't', "COMMANDFMT", 0,
       "register one translator to call", 0 },
     { "timeout", 'T', "NUMBER", 0, "kill translators after NUMBER seconds", 0 },
+    { "list-shorthands", OPT_LIST, 0 , 0,
+      "list availabled shorthands to use in COMMANDFMT", 0},
     /**************************************************/
     { 0, 0, 0, 0,
       "COMMANDFMT should specify input and output arguments using the "
@@ -369,6 +429,9 @@ static int parse_opt_trans(int key, char* arg, struct argp_state*)
 		<< "on your platform" << std::endl;
 #endif
       break;
+    case OPT_LIST:
+      show_shorthands();
+      exit(0);
     default:
       return ARGP_ERR_UNKNOWN;
     }

src/tgbatest/ltldo2.test

@@ -27,5 +27,5 @@ genltl=../../bin/genltl
 test -n "$LTL2BA" || exit 77
 
 $genltl --or-g=1..2 |
-    run 0 $ltldo '{ltl2ba}ltl2ba -f %s>%H' >output
-test 2 = `grep -c digraph output`
+    run 0 $ltldo 'ltl2ba -f %s>%H' '{foo}ltl2ba' >output
+test 4 = `grep -c digraph output`