start work on exception handling

CXX/yapi.cpp

@@ -379,7 +379,7 @@ YAPPredicate::YAPPredicate(const char *s, Term **outp, term_t &vnames) throw (in
   vnames = Yap_NewSlots(1 PASS_REGS);
   Term t = Yap_StringToTerm(s, strlen(s)+1, vnames);
   if (t == 0L)
-    throw YAPError::SYNTAX_ERROR;
+    throw SYNTAX_ERROR;
   ap = getPred( t, outp );
   //{ CACHE_REGS __android_log_print(ANDROID_LOG_ERROR,  __FUNCTION__, "OUT vnames=%d ap=%p LCL0=%p",  vnames, ap, LCL0) ; }
 }
@@ -446,7 +446,7 @@ YAPQuery::initQuery( Term *ts )
   LOCAL_execution = (struct open_query_struct *)this;
   this->q_open=1;
   this->q_state=0;
-  this->q_flags = 0;
+  this->q_flags = PL_Q_PASS_EXCEPTION;
   this->q_g = ts;
 }
 
@@ -493,7 +493,7 @@ bool YAPQuery::next()
     return false;
   // don't forget, on success these guys must create slots
   if (this->q_state == 0) {
-      extern void toggle_low_level_trace(void);
+    // extern void toggle_low_level_trace(void);
       //toggle_low_level_trace();
       result = (bool)YAP_EnterGoal((YAP_PredEntryPtr)this->ap, this->q_g, &this->q_h);
   } else {
@@ -537,7 +537,9 @@ void YAPQuery::close()
 int YAPPredicate::call(YAPTerm t[])
 {
   YAPQuery q = YAPQuery(*this, t);
-  int ret = q.next();
+  int ret;
+
+  ret = q.next();
   q.cut();
   q.close();
   return ret;
@@ -628,12 +630,14 @@ YAPQuery *YAPEngine::query( char *s ) {
 }
 
 YAPQuery *YAPEngine::safeQuery( char *s ) {
-  try 
-    {
-      YAPQuery *n = new YAPQuery( s );
-      return n;
-    }
-  catch (...) {
-    return 0;
-  }
+     try {
+       YAPQuery *n = new YAPQuery( s );
+       n->setFlag( PL_Q_CATCH_EXCEPTION );
+       n->resetFlag( PL_Q_PASS_EXCEPTION );
+       return n;
+     } 
+     catch (yap_error_number errno) {
+       error = errno;
+       return 0;
+     }
 }

CXX/yapi.hh

@@ -94,10 +94,6 @@ class YAPApplTerm;
 class YAPPairTerm;
 class YAPQuery;
 
-#include "yapie.hh"
-
-class TypeError {};
-
 /**
  * @brief Generic Prolog Term
  */
@@ -425,7 +421,7 @@ public:
     Term t, tp;
     t = YAP_ReadBuffer(s,&tp);
     if (t == 0L)
-      throw YAPError::SYNTAX_ERROR;
+      throw SYNTAX_ERROR;
     ap = getPred( t, (Term **)NULL );
   }
 
@@ -437,7 +433,7 @@ public:
     Term t, tp;
     t = YAP_ReadBuffer(s,&tp);
     if (t == 0L)
-      throw YAPError::SYNTAX_ERROR;
+      throw SYNTAX_ERROR;
     ap = getPred( t, (Term **)NULL );
   }
 
@@ -515,6 +511,10 @@ public:
 
     initQuery( ts );
   }
+  /// set flags for query execution, currently only for exception handling
+  void setFlag(int flag) {q_flags |= flag; }
+  /// reset flags for query execution, currently only for exception handling
+  void resetFlag(int flag) {q_flags &= ~flag; }
   ///  first query
   ///
   /// actually implemented by calling the next();
@@ -551,6 +551,7 @@ class YAPEngine {
 private:
   YAPCallback *_callback;
   YAP_init_args init_args;
+  yap_error_number error;
 public:
   YAPEngine(char *savedState = (char *)NULL,
             size_t stackSize = 0,
@@ -569,15 +570,17 @@ public:
   /// remove current callback
   void delYAPCallback() { _callback = 0; }
   /// set a new callback
-  void setYAPCallback(YAPCallback *cb) { delYAPCallback(); _callback = cb; __android_log_print(ANDROID_LOG_INFO, __FILE__, "after loading startup %p",cb); }
+  void setYAPCallback(YAPCallback *cb) { delYAPCallback(); _callback = cb; }
   /// execute the callback.
   void run() { if (_callback) _callback->run(); }
   /// execute the callback with a text argument.
-  void run( char *s) { __android_log_print(ANDROID_LOG_INFO, __FUNCTION__, "bef calling disp %s %p",s, _callback);  if (_callback) _callback->run(s); }
+  void run( char *s) {  if (_callback) _callback->run(s); }
   /// build a query on the engine
   YAPQuery *query( char *s );
-  /// build a query on the engine
+  /// build a query on the engine handling exceptions
   YAPQuery *safeQuery( char *s );
+
+  yap_error_number hasError(  ); //> report whether the engine has found an error
 };
 
 /*

CXX/yapie.hh

@@ -10,7 +10,27 @@ class YAPPredicate;
 
 class YAPError {
 public:
-  static const int SYNTAX_ERROR = 0x10000;
+  static const int SYNTAX_ERROR = 0x10000; //> syntax error
+  static const int DOMAIN_ERROR = 0x20000;  //> usually illegal parameter, like asin( 2 )
+  static const int TYPE_ERROR = 0x40000; //> usually illegal parameter in the language, like ( 2 mod 3.0 )
+  static const int PERMISSION_ERROR = 0x80000; //> wrong para,eter
+  static const int EVALUATION_ERROR = 0x100000; //> bad arithmetic expressions
+  static const int RESOURCE_ERROR = 0x200000;   //> no resource available, like MEM
+  static const int REPRESENTATION_ERROR = 0x400000; //> bad UTF-8 strings, etc
+  static const int EXISTËNCE_ERROR = 0x400000; //> object not found
+  static const int PROFILER = 0x400000; //> improve profiling support.
+  static const int OTHER_ERROR = 0x800000; //> anything rldr.,,,,,,,,,,,,,,,,,,,,
 };
 
+class YAPErrorClass {
+public:
+  static const int SYNTAX_ERROR = 0x10000;
+  static const int DOMAIN_ERROR = 0x20000;
+  static const int TYPE_ERROR = 0x40000;
+  static const int PERMISSION_ERROR = 0x80000;
+  static const int EVALUATION_ERROR = 0x100000;
+  static const int RESOURCE_ERROR = 0x200000;
+  static const int REPRESENTATION_ERROR = 0x400000;
+  static const int OTHER_ERROR = 0x800000;
+};