Oleo
11.1 Boolean Functions
Boolean functions return either a #TRUE or #FALSE value.
Most arguments (those labelled bool) are also boolean. If these
arguments have any other value instead, the function returns
#NON_BOOL as an error.
if(bool, val1, val2)
- @findex if
If bool is
#TRUE, then val1 is returned. If
bool is #FALSE, val2 is returned.
and(bool1, bool2)
- @findex and
Returns
#TRUE if and only if both arguments are #TRUE,
otherwise returns #FALSE.
or(bool1, bool2)
- @findex or
Returns
#TRUE if either or both arguments are #TRUE,
otherwise returns #FALSE.
not(bool)
- Returns
#TRUE if bool is #FALSE; #FALSE if
#TRUE.
iserr(val)
- returns
#TRUE if val is an error, #FALSE
otherwise.
isnum(val)
-
#TRUE if val is a number, or can be automatically
converted to a number. Thus, isnum("12") is #TRUE, while
isnum("foobar") is #FALSE.
