extend("array")
# 1) Provide only the array; leave the item as a placeholder.
# This yields a partial function waiting for the item.
addTo123 = array:append(_, [1,2,3])
# Now call that partial with the missing item => 4
sput(addTo123(4))
# prints => [1,2,3,4]
# 2) Provide only the item, leaving the array as a placeholder.
# This yields a partial function waiting for the array.
append42 = array:append(42, _)
# Now call that partial with some array => [10,20]
sput(append42([10,20]))
# prints => [10,20,42]
# 3) If the second argument is a single string, append
# does string concatenation instead of array push:
stringPartial = array:append("World!", _)
sput( stringPartial("Hello, ") )
# prints => "Hello, World!"
sput(array:append(1, [13,15]))