orddict

append(Key, Value, Orddict1) -> Orddict2

Types

Appends a new Value to the current list of values associated with Key. An exception is generated if the initial value associated with Key is not a list of values.

See also section Notes.

append_list(Key, ValList, Orddict1) -> Orddict2

Types

Appends a list of values ValList to the current list of values associated with Key. An exception is generated if the initial value associated with Key is not a list of values.

See also section Notes.

erase(Key, Orddict1) -> Orddict2

Types

Erases all items with a specified key from a dictionary.

fetch(Key, Orddict) -> Value

Types

Returns the value associated with Key in dictionary Orddict. This function assumes that the Key is present in the dictionary. An exception is generated if Key is not in the dictionary.

See also section Notes.

fetch_keys(Orddict) -> Keys

Types

Returns a list of all keys in a dictionary.

take(Key, Orddict) -> {Value, Orddict1} | error

OTP 20.0

Types

This function returns value from dictionary and new dictionary without this value. Returns error if the key is not present in the dictionary.

filter(Pred, Orddict1) -> Orddict2

Types

Orddict2 is a dictionary of all keys and values in Orddict1 for which Pred(Key, Value) is true.

find(Key, Orddict) -> {ok, Value} | error

Types

Searches for a key in a dictionary. Returns {ok, Value}, where Value is the value associated with Key, or error if the key is not present in the dictionary.

See also section Notes.

fold(Fun, Acc0, Orddict) -> Acc1

Types

Calls Fun on successive keys and values of Orddict together with an extra argument Acc (short for accumulator). Fun must return a new accumulator that is passed to the next call. Acc0 is returned if the list is empty.

from_list(List) -> Orddict

Types

Converts the Key-Value list List to a dictionary.

is_empty(Orddict) -> boolean()

OTP 17.0

Types

Returns true if Orddict has no elements, otherwise false.

is_key(Key, Orddict) -> boolean()

Types

Tests if Key is contained in dictionary Orddict.

map(Fun, Orddict1) -> Orddict2

Types

Calls Fun on successive keys and values of Orddict1 tvo return a new value for each key.

merge(Fun, Orddict1, Orddict2) -> Orddict3

Types

Merges two dictionaries, Orddict1 and Orddict2, to create a new dictionary. All the Key-Value pairs from both dictionaries are included in the new dictionary. If a key occurs in both dictionaries, Fun is called with the key and both values to return a new value. merge/3 can be defined as follows, but is faster:

merge(Fun, D1, D2) ->
    fold(fun (K, V1, D) ->
                 update(K, fun (V2) -> Fun(K, V1, V2) end, V1, D)
         end, D2, D1).

new() -> orddict()

Creates a new dictionary.

size(Orddict) -> integer() >= 0

Types

Returns the number of elements in an Orddict.

store(Key, Value, Orddict1) -> Orddict2

Types

Stores a Key-Value pair in a dictionary. If the Key already exists in Orddict1, the associated value is replaced by Value.

to_list(Orddict) -> List

Types

Converts a dictionary to a list representation.

update(Key, Fun, Orddict1) -> Orddict2

Types

Updates a value in a dictionary by calling Fun on the value to get a new value. An exception is generated if Key is not present in the dictionary.

update(Key, Fun, Initial, Orddict1) -> Orddict2

Types

Updates a value in a dictionary by calling Fun on the value to get a new value. If Key is not present in the dictionary, Initial is stored as the first value. For example, append/3 can be defined as follows:

append(Key, Val, D) ->
    update(Key, fun (Old) -> Old ++ [Val] end, [Val], D).

update_counter(Key, Increment, Orddict1) -> Orddict2

Types

Adds Increment to the value associated with Key and store this value. If Key is not present in the dictionary, Increment is stored as the first value.

This can be defined as follows, but is faster:

update_counter(Key, Incr, D) ->
    update(Key, fun (Old) -> Old + Incr end, Incr, D).

> D0 = orddict:new(),
  D1 = orddict:store(files, [], D0),
  D2 = orddict:append(files, f1, D1),
  D3 = orddict:append(files, f2, D2),
  D4 = orddict:append(files, f3, D3),
  orddict:fetch(files, D4).
[f1,f2,f3]