Exception handling syntax

Some_Error : exception;

raise Some_Error;
 
raise Some_Error with "Out of memory"; -- specific diagnostic message

with Ada.Exceptions, Ada.Text_IO;
 
procedure Foo is
  Some_Error : exception;
begin
  Do_Something_Interesting;
exception -- Start of exception handlers
  when Constraint_Error =>
    ... -- Handle constraint error
  when Storage_Error =>
    -- Propagate Storage_Error as a different exception with a useful message
    raise Some_Error with "Out of memory";
  when Error : others => 
    -- Handle all others
    Ada.Text_IO.Put("Exception: ");
    Ada.Text_IO.Put_Line(Ada.Exceptions.Exception_Name(Error));
    Ada.Text_IO.Put_Line(Ada.Exceptions.Exception_Message(Error));
end Foo;

ON ERROR GOTO handler
OPEN "Somefile.txt" FOR INPUT AS #1
CLOSE #1
PRINT "File opened successfully"
END
 
handler:
PRINT "File does not exist"
END

#include <setjmp.h>
#include <stdio.h>
enum { SOME_EXCEPTION = 1 };
jmp_buf state;
int main()
{
  int exception;
  if((exception = setjmp(state)) == 0)  // try
  {
    if(/* something happened */)
      longjmp(state, SOME_EXCEPTION);   // throw SOME_EXCEPTION
  } 
  else switch(exception)
  {             
    case SOME_EXCEPTION:                  // catch SOME_EXCEPTION
      puts("SOME_EXCEPTION caught");
      break;
    default:                              // catch ...
      puts("Some strange exception");
  }
  return 0;
}

int filterExpression (EXCEPTION_POINTERS* ep) {
   ++ep->ContextRecord->Eip;
   return EXCEPTION_CONTINUE_EXECUTION;
}
int main() {
   static int zero;
   __try {
       zero = 1/zero;
       printf ("Past the exception.\n");
   } __except (filterExpression (GetExceptionInformation())) {
       printf ("Handler called.\n");
   }
   return 0;
}

public static void Main()
{
   try
   {
      // Code that could throw an exception
   }
   catch(System.Net.WebException exp)
   {
      // Process a WebException
   }
   catch(System.Exception)
   {
      // Process a System level CLR exception, that is not a System.Net.WebException,
      // since the exception has not been given an identifier it cannot be referenced
   }
   catch
   {
      // Process a non-CLR exception
   }
   finally
   {
      // (optional) code that will *always* execute
   }
}

#include <exception>
int main() {
   try {
       // do something (might throw an exception)
   }
   catch (const std::exception& e) {
        // handle exception e
   }
   catch (...) {
        // unknown exception, should not happen
   }
}

import std.stdio; // for writefln()
int main() {
  try {
      // do something that might throw an exception
  }
  catch (FooException e) {
       // handle exceptions of type FooException
  }
  catch (Object o) {
       // handle any other exceptions
       writefln("Unhandled exception: ", o);
       return 1;
  }
  return 0;
}

try
  try
    // Code which may raise an exception
  except
    on E:Exception do
    // Code to call when an exception is raised
  end;
finally
  // Code which will be executed whether or not an exception is raised (e.g. clean-up code)
end;

try {
   // Normal execution path
} catch (ExampleException ee) {
   //  deal with the ExampleException
} finally {
   // This optional section is executed upon termination of any of the try or catch blocks above
}

try {
  // Statements in which exceptions might be thrown
} catch(error) {
  // Statements that execute in the event of an exception
} finally {
  // Statements that execute afterward either way
}

(ignore-errors (/ 1 0))
 
(handler-case
    (progn
      (print "enter an expression")
      (eval (read)))
  (error (e) (print e)))

NSException *exception = [NSException exceptionWithName:@"myException"
                           reason:@"whatever"  userInfo:nil];

@throw exception;

@try {
    ...
}
@catch (SomeException *se) {
    // Handle a specific exception type.
    ...
}
@catch (NSException *ne) {
    // Handle general exceptions.
    ...
 
    // Propagate the exception so that it's handled at a higher level.
    @throw;
}
@catch (id ue) {
    // Catch all thrown objects.
    ...
}
@finally {
    // Perform cleanup, whether an exception occurred or not.
    ...
}

exception MyException of string * int (* exceptions can carry a value *)
let _ =
  try
    raise (MyException ("not enough food", 2));
    print_endline "Not reached"
  with
  | MyException (s, i) -> 
      Printf.printf "MyException: %s, %d\n" s i
  | _ ->  (* catch all exceptions *)
      print_endline "Unexpected exception"

eval {
  # Code that could throw an exception (using 'die')
  open(FILE, $file) || die "Could not open file: $!";
  while (<FILE>) {
    process_line($_);
  }
  close(FILE) || die "Could not close $file: $!";
};
if ($@) {
  # Handle exception here. The exception string is in $@
}

eval {
  open(FILE, $file) || die MyException::File->new($!);
  while (<FILE>) {
    process_line($_);
  }
  close(FILE) || die MyException::File->new($!);
};
if ($@) {
  # The exception object is in $@
  if ($@->isa('MyException::File')) {
    # Handle file exception
  } else {
    # Generic exception handling
    # or re-throw with 'die $@'
  }
}

local $SIG{__DIE__} = sub {
  my $err = shift;
  if ($err->isa('MyException')) {
    die $err; # re-throw
  } else {
    # Otherwise construct a MyException with $err as a string
    die MyException::Default->new($err);
  }
};

// Exception handling is only available in PHP versions 5 and greater.
try
{
... // Code which might throw an exception
}
catch (FirstExceptionClass $exception) 
{
... // Code which handles this exception
} 
catch (SecondExceptionClass $exception) 
{
  // you get the idea what i mean ;)
}

TRY
   // Normal execution path
CATCH (ExampleException ee)
   //  deal with the ExampleException
FINALLY
   // This optional section is executed upon termination of any of the try or catch blocks above
END TRY

f = None
try:
   f = file("aFileName")
   f.write(could_make_error())
except IOError:
   print "Unable to open file"
except:   # catch all exceptions
   print "Unexpected error"
else:     # executed if no exceptions are raised
   print "File write completed successfully"
finally:  # clean-up actions, always executed
   if f:
      f.close()

begin
  # Do something nifty
  raise SomeError, "This is the error message!"  # Uh-oh!
rescue SomeError
  # This is executed when a SomeError exception
  # is raised
rescue AnotherError => error
  # Here, the exception object is referenced from the
  # `error' variable
else
  # This is executed only if no exceptions were raised
ensure
  # This is always executed, exception or not
end

Try
   ' Do Something
Catch ex As Exception When condition
   ' Handle Exception when a specific condition is true
Catch ex As Exception
   ' Handle Exception
Finally
   ' Cleanup, close connections etc
   ' NB this code is always executed regardless of if an Exception was raised or not!
End Try

trap [Exception]
{
  // Statements that execute in the event of an exception
}
// Statements in which exceptions might be thrown