Dict
implements a Key
- Value
dictionary.
append(Key, Value, Dict1) -> Dict2
Key = Value = term()
Dict1 = Dict2 = dictionary()
This function 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.
append_list(Key, ValList, Dict1) -> Dict2
ValList = [Value]
Key = Value = [term()]
Dict1 = Dict2 = dictionary()
This function 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.
Dict = dictionary()
List = [{Key, Value}]
This function converts the dictionary to a list representation.
Key = term()
Dict1 = Dict2 = dictionary()
This function erases all items with a given key from a dictionary.
Key = Value = term()
Dict = dictionary()
This function returns the value associated with Key
in the
dictionary Dict
. fetch
assumes that
the Key
is present in the dictionary and an exception
is generated if Key
is not in the dictionary.
Dict = dictionary()
Keys = [term()]
This function returns a list of all keys in the dictionary.
Key = term()
Dict = dictionary()
Result = {ok, Value} | error
This function 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.
Key = term()
Dict = dictionary()
This function tests if Key
is contained in the dictionary Dict
This function creates a new dictionary.
store(Key, Value, Dict1) -> Dict2
Key = Value = term()
Dict1 = Dict2 = dictionary()
This function stores a Key
- Value
pair in a dictionary. If the
Key
already exists in Dict1
, the associated value
is replaced by Value
.
The functions append
and append_list
are included
so we can store keyed values in a list accumulator. For
example:
> D0 = dict:new(), D1 = dict:store(files, [], D0), D2 = dict:append(files, f1, D1), D3 = dict:append(files, f2, D2), D4 = dict:append(files, f3, D3), dict:fetch(files, D4). [f1,f2,f3]
This saves the trouble of first fetching a keyed value, appending a new value to the list of stored values, and storing the result.
The function fetch
should be used if the key is known to
be in the dictionary, otherwise find
.