* src/ltlparse/public.hh (format_parse_errors): New function.

* src/ltlparse/fmterror.cc: New file.
* src/ltlparse/Makefile.am (libltlparse_a_SOURCES): Add fmterror.cc.
* src/ltltests/equals.cc, src/ltltests/readltl.cc: Simplify using
format_parse_errors.

src/ltlparse/Makefile.am

@@ -21,6 +21,7 @@ $(FROM_LTLPARSE_YY_OTHERS): $(LTLPARSE_YY)
 	@test -f $@ || $(MAKE) $(AM_MAKEFLAGS) $(FROM_LTLPARSE_YY_MAIN)
 
 libltlparse_a_SOURCES = \
+  fmterror.cc \
   $(FROM_LTLPARSE_YY) \
   ltlscan.ll \
   parsedecl.hh \

src/ltlparse/fmterror.cc

@@ -0,0 +1,35 @@
+#include "public.hh"
+
+namespace spot 
+{
+  namespace ltl
+  {
+
+    bool 
+    format_parse_errors(std::ostream& os,
+			const std::string& ltl_string,
+			parse_error_list& error_list)
+    {
+      bool printed = false;
+      spot::ltl::parse_error_list::iterator it;
+      for (it = error_list.begin(); it != error_list.end(); ++it)
+	{
+	  os << ">>> " << ltl_string << std::endl;
+	  yy::Location& l = it->first;
+
+	  unsigned n = 0;
+	  for (; n < 4 + l.begin.column; ++n)
+	    os << ' ';
+	  // Write at least one '^', even if begin==end.
+	  os << '^';
+	  ++n;
+	  for (; n < 4 + l.end.column; ++n)
+	    os << '^';
+	  os << std::endl << it->second << std::endl << std::endl;
+	  printed = true;
+	}
+      return printed;
+    }
+
+  }
+}

src/ltlparse/public.hh

@@ -6,6 +6,7 @@
 # include "location.hh"
 # include <list>
 # include <utility>
+# include <iostream>
 
 namespace spot 
 {
@@ -18,6 +19,11 @@ namespace spot
     formulae* parse(const std::string& ltl_string, 
 		    parse_error_list& error_list,
 		    bool debug = false);
+
+    // Return true iff any diagnostic was output to os.
+    bool format_parse_errors(std::ostream& os,
+			     const std::string& ltl_string,
+			     parse_error_list& error_list);
   }
 }