/* Catch.m
 *
 * Copyright Niels Möller <nisse@lysator.liu.se> 1995
 *
 * Freely distributable under the terms and conditions of the
 * GNU General Public License.
 */

#include <Catch.h>
#include <Error.h>

/* I'm not sure if I should hardcode StackFrame here or not. */
#ifndef FRAME_STACK
#define FRAME_STACK [self class]
#endif FRAME_STACK


@implementation Catch_common
- (catch_buf *) where { return &where; } 
- (catch_buf *) catch;
{
  if (frame)
    [self cleanup];
  frame = [FRAME_STACK pushCatch: self];
  return [self where];
}
@end /* Catch_common */


@implementation Catch
- value { return result; }
- value: newValue { result = newValue; return self; }

- (BOOL) matches: tag
{
  return [tag isEqual: self];
}

- (void) throw: value
{
  [self throw: value : 17 free: YES];
}

- (void) throwInt: (int) value
{
  [self throw: nil : value free: NO];
}

- (void) throw: value1 : (int) value2 free: (BOOL) freeFlag
{
  frame_id fr;
  id catch;
  
  fr = [FRAME_STACK findFrameMatching: self];
  if (fr)
    {
      [FRAME_STACK unwind: fr];
      catch = ( (struct frstack_catch_object_frame *) fr)->object;
      
      [catch value: value1];

      /* If freeFlag is true, and we are not the same object as the one
       * used in the catch, free. */
      if (freeFlag && !(catch == self))
	[self free];
      longjmp([catch where]->jmp, value2);
      /* Never returns here */
    }

  /* No matching catch found. Try signalling an error. */
  
  [[[[ErrorNoCatch alloc] value: value1] tag: self] raise];
  /* Dead end */
}
@end /* Catch */


@implementation CatchError
- errorClass { return errorClass; }
- errorClass: class { errorClass = class; return self; }
- error { return result; }
- setError: object { result = object; return self; }

- (catch_buf *) catch: class
{
  return [ [self errorClass: class] catch];
}

- (BOOL) matches: tag
{
  return [tag isKindOf: errorClass];
}
@end /* CatchError */