Maps and Sets are not well suited for random access. They are ordered and their length is known, but they are not indexed for access by an order index. As such, to get the Nth item in a Map or Set, you have to iterate through it to find that item. The simple way to … Read more
Simply do: _objTable.removeWhere((key, value) => key == “propertyName”); It works with nested Maps too.
As I understand it, the function “executes” each element in the list which must be an “action” (IO monad). That’s true for IO, but in your code example you don’t use the IO monad, you use the list monad (the function you give to mapM returns a list ([x]), not an IO). mapM is defined … Read more
Deletion of map elements The built-in function delete removes the element with key k from a map m. delete(m, k) // remove element m[k] from map m For example, package main import “fmt” func main() { m := map[string]string{“key1”: “val1”, “key2”: “val2”} fmt.Println(m) delete(m, “key1”) fmt.Println(m) } Output: map[key1:val1 key2:val2] map[key2:val2]
In your example the map key is a pointer to the struct, not the struct itself. Pointers can be compared for equality even when the items they point to can’t be compared. This comparison is not based on the contents of the item, but only on its memory address.
If you download just the database files from wordnet.princeton.edu/download/current-version you can extract the words by running these commands: egrep -o “^[0-9]{8}\s[0-9]{2}\s[a-z]\s[0-9]{2}\s[a-zA-Z_]*\s” data.adj | cut -d ‘ ‘ -f 5 > conv.data.adj egrep -o “^[0-9]{8}\s[0-9]{2}\s[a-z]\s[0-9]{2}\s[a-zA-Z_]*\s” data.adv | cut -d ‘ ‘ -f 5 > conv.data.adv egrep -o “^[0-9]{8}\s[0-9]{2}\s[a-z]\s[0-9]{2}\s[a-zA-Z_]*\s” data.noun | cut -d ‘ ‘ -f 5 … Read more
As notification.userInfo type is AnyObject ayou must downcast it to appropriate dictionary type. After exact type of dictionary is known you don’t need to downcast values you get from it. But you may want to check if values are actually present in dictionary before using them: // First try to cast user info to expected … Read more
You can’t change values associated with keys in a map, you can only reassign values. This leaves you 2 possibilities: Store pointers in the map, so you can modify the pointed object (which is not inside the map data structure). Store struct values, but when you modify it, you need to reassign it to the … Read more
Since the Map consists of Entrys and it is not Iterable you can use Map#entries instead. It will be mapped to Map#entrySet to create a backed view of Set<Entry>, for example: val reversed = map.entries.associateBy({ it.value }) { it.key } OR use Iterable#associate, which will create additional Pairs. val reversed = map.entries.associate{(k,v)-> v to k} … Read more
You need to initialize it with an empty map: var ir_MAP = map[int]ir_table{} or, as “the system” suggested: var ir_MAP = make(map[int]ir_table) The problem is that the zero value of a map is nil, and you can’t add items to a nil map.