Merge pull request #61 from linas/silent

Add yet another exception type.

Author: linas

opencog/util/exceptions.cc

@@ -308,27 +308,3 @@ AssertionException::AssertionException(const char* fmt, va_list ap)
     set_message(buf);
     opencog::logger().error("%s", buf);
 }
-
-/*
- * ----------------------------------------------------------------------
- * DeleteException class
- * ----------------------------------------------------------------------
- */
-DeleteException::DeleteException(void)
-{}
-
-/*
- * ----------------------------------------------------------------------
- * NotEvaluatableException class
- * ----------------------------------------------------------------------
- */
-NotEvaluatableException::NotEvaluatableException(void)
-{}
-
-/*
- * ----------------------------------------------------------------------
- * TypeCheckException class
- * ----------------------------------------------------------------------
- */
-TypeCheckException::TypeCheckException(void)
-{}

opencog/util/exceptions.h

@@ -272,76 +272,113 @@ class AssertionException : public StandardException
     AssertionException(const char* fmt, va_list ap);
 };
 
+/* ---------------------------------------------------------------- */
 /**
- * Exception to be called when the searched item was not found
+ * Base class for exceptions that don't write to the error log.
+ *
+ * These exceptions will not log an error when thrown, because the
+ * exception is thrown during normal processing, and is not an error.
+ */
+class SilentException : public RuntimeException
+{
+public:
+    /**
+     * Constructor
+     * Nothing to be logged; this simply breaks us out of inner loops.
+     */
+    SilentException(void) {}
+
+}; // SilentException
+
+/**
+ * Exception thrown when the DeleteLink executes.
  *
  * This exception will not log an error when thrown, because the
- * error must be handled inside the code.
+ * exception is thrown during normal processing, and is not an error.
  */
-class NotFoundException : public StandardException
+class DeleteException : public SilentException
 {
 public:
     /**
      * Constructor
-     *
-     * @param Trace information (filename:line-number). Use TRACE_INFO
-     * macro.
-     * @param Exception message in printf standard format.
+     * Nothing to be logged; this simply breaks us out of inner loops.
      */
-    NotFoundException(const char*, const char*, ...);
+    DeleteException(void) {}
 
-}; // NotFoundException
+}; // DeleteException
 
 /**
- * Exception thrown when an expression is not evaluatable.
+ * Exception thrown when an expression is badly nested.
+ * Typical usage is when QuoteLink contexts seem to be confused.
  *
  * This exception will not log an error when thrown, because the
  * exception is thrown during normal processing, and is not an error.
  */
-class NotEvaluatableException : public RuntimeException
+class NestingException : public SilentException
 {
 public:
     /**
      * Constructor
      * Nothing to be logged; this simply breaks us out of inner loops.
      */
-    NotEvaluatableException(void);
+    NestingException(void) {}
 
-}; // NotEvaluatableException
+}; // NestingException
 
 /**
- * Exception thrown when an expression is of the wrong type.
+ * Exception thrown when an expression is not evaluatable.
  *
  * This exception will not log an error when thrown, because the
  * exception is thrown during normal processing, and is not an error.
  */
-class TypeCheckException : public RuntimeException
+class NotEvaluatableException : public SilentException
 {
 public:
     /**
      * Constructor
      * Nothing to be logged; this simply breaks us out of inner loops.
      */
-    TypeCheckException(void);
+    NotEvaluatableException(void) {}
 
-}; // TypeCheckException
+}; // NotEvaluatableException
 
 /**
- * Exception thrown when the DeleteLink executes.
+ * Exception to be called when the searched item was not found
+ *
+ * This exception will not log an error when thrown, because the
+ * error must be handled inside the code.
+ */
+class NotFoundException : public SilentException
+{
+public:
+    /**
+     * Constructor
+     *
+     * @param Trace information (filename:line-number). Use TRACE_INFO
+     * macro.
+     * @param Exception message in printf standard format.
+     */
+    NotFoundException(void) {}
+    NotFoundException(const char*, const char*, ...);
+
+}; // NotFoundException
+
+/**
+ * Exception thrown when an expression is of the wrong type.
  *
  * This exception will not log an error when thrown, because the
  * exception is thrown during normal processing, and is not an error.
  */
-class DeleteException : public RuntimeException
+class TypeCheckException : public SilentException
 {
 public:
     /**
      * Constructor
      * Nothing to be logged; this simply breaks us out of inner loops.
      */
-    DeleteException(void);
+    TypeCheckException(void) {}
 
-}; // DeleteException
+}; // TypeCheckException
 
 inline std::ostream& operator<<(std::ostream& out,
                                 const StandardException& ex)