Not empty version of Dict

Create a non empty dictionary with one key-value pair.

Create a non empty dictionary from a regular dictionary and a given pair.

In contrast to fromDict this will always return a value since there is always at least 1 pair.

dict = withPair 5 "Five" ( Dict.fromList [ ( 4, "Four" ), ( 3, "Three" ) ] )
toDict dict == Dict.fromList [ ( 3, "Three" ), ( 4, "Four" ), ( 5, "Five" ) ]

Same as Dict.fromList except using a NotEmpty.List

Same as withPair but with a list or pairs instead of a dict

Convert a regular dict into a not empty dict, or Nothing if the dict is empty

fromDict ( Dict.fromList [] ) == Nothing
fromDict ( Dict.fromList [ ( 1, "one" ), ( 2, "two" ), ( 3, "three" ) ] ) == Just ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] )

Convert a not empty dict into a regular dict

toDict ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == Dict.fromList [ ( 1, "one" ), ( 2, "two" ), ( 3, "three" ) ]
toDict ( singleton 1 "one" ) == Dict.fromList [ ( 1, "one" ) ]

Extract the first pair from a not empty dictionary.

head ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == ( 1, "one" )
head ( singleton 1 "one" ) == ( 1, "one" )

Extract the last pair from a not empty dictionary.

last ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == ( 3, "three" )
last ( singleton 1 "one" ) == ( 1, "one" )

Returns the elements after the first pair as a regular dictionary

tail ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == Dict.fromList [ ( 2, "two" ), ( 3, "three" ) ]
tail ( singleton 1 "one" ) == Dict.fromList []

Returns wether the dictionary has a tail with elements

hasTail ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == True
hasTail ( singleton 1 "one" ) == False
hasTail ( fromListWithHead 1 "one" [] ) == False

Same as Dict.remove but will return Nothing if the last value is removed

remove 1 ( fromListWithPair 1 "one" [ ( 2, "two" ), ( 3, "three" ) ] ) == Just ( fromListWithPair 2 "two" [ ( 3, "three" ) ] )
remove 1 ( singleton 1 "one" ) == Nothing
remove 2 ( singleton 1 "one" ) == Just ( singleton 1 "one" )

Same as Dict.filter but will return Nothing if no pairs satisfy the test

filter isKeyEven ( fromListWithPair 1 1 [ ( 2, 2 ), ( 3, 3 ) ] ) == Just ( fromListWithPair 2 2 [] )
filter isKeyEven ( singleton 1 1 ) == Nothing

Same as Dict.diff but will return Nothing if the resulting dictionary is empty

diff ( fromListWithPair 1 1 [ ( 2, 2 ), ( 3, 3 ) ] ) ( singleton 1 "one" ) == Just ( fromListWithPair 2 2 [ ( 3, 3 ) ] )
diff ( singleton 1 1 ) ( singleton 1 "one" ) == Nothing
diff ( singleton 2 2 ) ( singleton 1 "one" ) == Just ( singleton 2 2 )

Same as Dict.intersect but will return Nothing if the resulting dictionary is empty

intersect ( fromListWithPair 1 1 [ ( 2, 2 ), ( 3, 3 ) ] ) ( singleton 1 "one" ) == Just ( fromListWithPair 1 1 [] )
intersect ( singleton 1 1 ) ( singleton 1 "one" ) == Just ( singleton 1 1 )
intersect ( singleton 2 2 ) ( singleton 1 "one" ) == Nothing

Same as Dict.get

Same as Dict.member

Same as Dict.insert

Same as Dict.size

Same as Dict.toList

Same as Dict.map

Same as Dict.foldl

Same as Dict.foldr

Same as Dict.union

Same as Dict.merge