extend("array")
keyed = [ name:"Alice" ]
// Direct usage
slog( array:assoc("city", "London", keyed) ) // => [ name:"Alice", city:"London" ]
// Partial usage
setter = array:assoc("color", "blue")
slog( setter(keyed) ) // => [ name:"Alice", color:"blue" ]
// Placeholder usage
bananaSetter = array:assoc(_, "banana", keyed)
slog( bananaSetter("fruit") ) // => [ name:"Alice", fruit:"banana" ]