| and & perform boolean ``or" and ``and"
respectively. They require boolean operands and yield boolean
results. They work in the usual fashion with equal-sized vector
operands or one vector and one scalar. See § 3.2.4, page .
In addition to
| and &, Glish provides the related
operators, taken from C. These are
``short-circuit" operators; they evaluate their right-hand operand
only when needed. Unlike most of the other operands, these do not
perform element-by-element vector operations. Both operands should be
numeric scalars, though presently vector values are allowed, in
which case the first element of the vector is used.
|| operator evaluates its first operand and returns it if
true when considered as a boolean. Otherwise it evaluates and
returns its second operand. The
&& operator returns F if its
first operand evaluates to false, otherwise it evaluates and returns
its second operand.