noneare the 2 operators to build an option value.
isnoneare the 2 operators to test whether an option value is none or is some.
opt_getis the operator to extract the value from a
someoption value. It fails if the value is
*and the tuple value with
[ ]operator is used to project the tuple to one specific dimension:
<>comparison operators. You can also check for any of the possible values with
match ... with endinstruction:
colorvalue the following way: