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/*
* Demonstrates using continuations to
* restart execution after correcting
* an exceptional condition.
*
* Copyright © 2001 Bart Massey.
* All Rights Reserved. See the file COPYING in this directory
* for licensing information.
*
* Bart 2001/06/03
*/
exception div0_attempt(continuation c);
rational function f(int x) {
continuation c;
int y;
if ((y = setjmp(&c, 0)) != 0) {
printf("restarted after exception\n");
x = y;
} else {
if (x == 0) {
printf("raising exception\n");
raise div0_attempt(c);
}
}
printf("returning value\n");
return 1 / x;
}
rational function protected_f(int x) {
try {
return f(x);
} catch div0_attempt(c) {
printf("restarting after exception\n");
longjmp(c, 1);
}
printf("internal error\n");
return 0;
}
printf("%g\n", protected_f(2));
printf("%g\n", protected_f(0));
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