IF THEN ELSE Value Expression¶
Syntax¶
iteValExpr |
“IF” [[valExpr]] “THEN” [[valExpr]] “ELSE” [[valExpr]] “FI” |
Semantics¶
IF expr1
THEN expr2
ELSE expr3
FI
The type of expr1
must be Boolean. The type of expr2
must be
equal to the type of expr3
.
The expressions expr2
and expr3
are only evaluated after the
value of expr1
is evaluated to True
or False
, respectively.
For Boolean expressions in which the order of evaluation is irrelevant,
one could consider the equivalent
alternatives:
(
expr1
=>expr2
) /\ (not(expr1
) =>expr3
) or(
expr1
/\expr2
) \/ (not(expr1
) /\expr3
)