operator
has
with hasnt
will reverse the results.
shelf test: shelf-name (has | hasnt) key string-expression attribute shelf test: specified? attribute (has | hasnt) key string-expression or specified? data-attributes (has | hasnt) key string-expression
has key
is a test that determines if a shelf contains a key with the given string-expression.
hasnt key
returns the opposite results.
has key
can also be applied to an attribute shelf in a similar fashion.
The has key
test can also determine whether an element has an attribute declared for it. It can be used on both the data-attributes
and attributes
shelves.
For example, the following code shows how has key
can be used to test for a declared attribute:
global stream id-name ... output attributes key id-name when attributes has key id-name and attribute key id-name isnt implied
In this example, the has key
test is used to determine whether the switch shelf "assoc-list" currently contains an item with the name referred to by "%g(curr-key)"
.
global switch assoc-list variable initial {true, false, true} global integer item-no process set key of assoc-list[1] to "black" set key of assoc-list[2] to "gold" set key of assoc-list[3] to "red" submit "{gold}foo-stuff for report" find "{" [ \ "}"]+ => curr-key "}" do when assoc-list has key "%g(curr-key)" set item-no to item of assoc-list{"%g(curr-key)"} else ; An index of 0 means that the key wasn't found. set item-no to 0 done output "item-no = " || "d" % item-no || "%n" ; Output: "item-no = 2 ; foo-stuff for report"