| Calling Sequence
| assert(cond)
|
| Parameters
| | Name | Type | Description |
|
| cond
| boolean | a condition to be tested |
|
| Return Type
| NULL |
| Synopsis
| This function evaluates its argument, which is
expected to be true or false.
If it evaluates to true, it does nothing.
If it evaluates to false it produces an "assertion failed" error.
The first argument of the error is the unevaluated expression that
evaluated to false.
It is the easy to write assertions which upon failure will
automatically produce meaningful errors. |
| Examples
| > assert(1=2);;
Error, 1 = 2, assertion failed
> Probab := 1.001;
Probab := 1.0010
> e := [ traperror(assert( Probab >=0 and Probab <= 1))];
e := [0 <= Probab and Probab <= 1, assertion failed]
> length(e);
2
> e[1];
0 <= Probab and Probab <= 1
|
| See also
| error, lasterror, traperror |