Methods

try

#define try

Start an exception try block.

catch

#define catch(...)

Start an exception catch block, catching any objects listed in ... as the first name given. To catch any exception object leave argument list empty other than caught variable name.

#define throw

throw(E, F, ...)

Throw exception object E with format string F and arguments ....

exception_signals

void exception_signals(void);

exception_object

void exception_object(void);

Retrieve the current exception object.

exception_message

void exception_message(void);

Retrieve the current exception message.

Examples

Usage

var x = new(Table, String, Int);
set(x, $S("Hello"), $I(1));
set(x, $S("World"), $I(2));

try {
  get(x, $S("Missing"));
} catch (e in KeyError) {
  println("Got Exception: %$", e);
}

Exception

Exception Object

The Exception type provides an interface to the Cello Exception System. One instance of this type is created for each Thread and stores the various bits of data required for the exception system. It can be retrieved using the current function, although not much can be done with it.

Exceptions are available via the try, catch and throw macros. It is important that the catch part of the exception block is always evaluated otherwise the internal state of the exception system can go out of sync. For this reason please never use return inside a try block.

The exception_signals method can be used to register some exception to be thrown for any of the standard C signals.

To get the current exception object or message use the exception_message or exception_object methods.

Derives

Alloc$ alloc dealloc
Castcast
Cmpcmp eq neq gt lt ge le
Copycopy
Hashhash hash_data
Sizesize
Swapswap

Implements

Assignassign
Currentcurrent
Docname brief description definition
Lenlen
Newnew del construct destruct
Showshow look print scan
Startwith start stop join running

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Cello High Level C

Methods

Examples

Exception

Derives

Implements