Commit | Line | Data |
---|---|---|
03ac148f SK |
1 | %%%---------------------------------------------------------------------------- |
2 | %%% Equivalent to stdlib's orddict, but with a pretty (IMO), uniform interface. | |
3 | %%%---------------------------------------------------------------------------- | |
4 | -module(hope_kv_list). | |
5 | ||
6 | -behavior(hope_dictionary). | |
7 | ||
8 | -export_type( | |
9 | [ t/2 | |
10 | ]). | |
11 | ||
12 | -export( | |
13 | [ empty/0 | |
14 | , get/2 | |
15 | , set/3 | |
16 | , update/3 | |
70cf8e86 | 17 | , pop/2 |
03ac148f SK |
18 | , iter/2 |
19 | , map/2 | |
20 | , filter/2 | |
21 | , fold/3 | |
22 | , of_kv_list/1 | |
23 | , to_kv_list/1 | |
fa24061d SK |
24 | , validate_unique_presence/2 % Assume default optional parameter(s) |
25 | , validate_unique_presence/3 % Specify optional parameter(s) | |
03ac148f SK |
26 | ]). |
27 | ||
28 | ||
29 | -type t(K, V) :: | |
30 | [{K, V}]. | |
31 | ||
fa24061d SK |
32 | -type presence_error(A) :: |
33 | {keys_missing , [A]} | |
34 | | {keys_duplicated , [A]} | |
35 | | {keys_unsupported , [A]} | |
36 | . | |
37 | ||
03ac148f SK |
38 | |
39 | %% ============================================================================ | |
40 | %% API | |
41 | %% ============================================================================ | |
42 | ||
43 | -spec empty() -> | |
44 | []. | |
45 | empty() -> | |
46 | []. | |
47 | ||
95c3c2a7 PO |
48 | -spec get(t(K, V), K) -> |
49 | hope_option:t(V). | |
03ac148f SK |
50 | get(T, K) -> |
51 | case lists:keyfind(K, 1, T) | |
52 | of false -> none | |
53 | ; {K, V} -> {some, V} | |
54 | end. | |
55 | ||
95c3c2a7 PO |
56 | -spec set(t(K, V), K, V) -> |
57 | t(K, V). | |
03ac148f SK |
58 | set(T, K, V) -> |
59 | lists:keystore(K, 1, T, {K, V}). | |
60 | ||
95c3c2a7 PO |
61 | -spec update(t(K, V), K, fun((hope_option:t(V)) -> V)) -> |
62 | t(K, V). | |
03ac148f SK |
63 | update(T, K, F) -> |
64 | V1Opt = get(T, K), | |
65 | V2 = F(V1Opt), | |
37c6e98b | 66 | % TODO: Eliminate the 2nd lookup. |
03ac148f SK |
67 | set(T, K, V2). |
68 | ||
95c3c2a7 PO |
69 | -spec pop(t(K, V), K) -> |
70 | {hope_option:t(V), t(K, V)}. | |
70cf8e86 SK |
71 | pop(T1, K) -> |
72 | case lists:keytake(K, 1, T1) | |
73 | of {value, {K, V}, T2} -> {{some, V}, T2} | |
74 | ; false -> {none , T1} | |
75 | end. | |
76 | ||
95c3c2a7 PO |
77 | -spec iter(t(K, V), fun((K, V) -> ok)) -> |
78 | ok. | |
c1672ac4 | 79 | iter(T, F1) -> |
d10156b0 | 80 | F2 = lift_map(F1), |
c1672ac4 | 81 | lists:foreach(F2, T). |
03ac148f | 82 | |
95c3c2a7 PO |
83 | -spec map(t(K, V), fun((K, V) -> V)) -> |
84 | t(K, V). | |
c1672ac4 | 85 | map(T, F1) -> |
d10156b0 SK |
86 | F2 = fun ({K, _}=X) -> {K, apply_map(F1, X)} end, |
87 | lists:map(F2, T). | |
03ac148f | 88 | |
95c3c2a7 PO |
89 | -spec filter(t(K, V), fun((K, V) -> boolean())) -> |
90 | t(K, V). | |
c1672ac4 | 91 | filter(T, F1) -> |
d10156b0 | 92 | F2 = lift_map(F1), |
c1672ac4 | 93 | lists:filter(F2, T). |
03ac148f | 94 | |
95c3c2a7 PO |
95 | -spec fold(t(K, V), fun((K, V, Acc) -> Acc), Acc) -> |
96 | Acc. | |
03ac148f SK |
97 | fold(T, F1, Accumulator) -> |
98 | F2 = fun ({K, V}, Acc) -> F1(K, V, Acc) end, | |
097a2aa3 | 99 | lists:foldl(F2, Accumulator, T). |
03ac148f | 100 | |
95c3c2a7 PO |
101 | -spec to_kv_list(t(K, V)) -> |
102 | [{K, V}]. | |
03ac148f SK |
103 | to_kv_list(T) -> |
104 | T. | |
105 | ||
95c3c2a7 PO |
106 | -spec of_kv_list([{K, V}]) -> |
107 | t(K, V). | |
03ac148f | 108 | of_kv_list(List) -> |
37c6e98b | 109 | % TODO: Decide if validation is to be done here. Do so if yes. |
03ac148f SK |
110 | List. |
111 | ||
fa24061d SK |
112 | -spec validate_unique_presence(t(K, _V), [K]) -> |
113 | hope_result:t(ok, [presence_error(K)]). | |
114 | validate_unique_presence(T, KeysRequired) -> | |
115 | KeysOptional = [], | |
116 | validate_unique_presence(T, KeysRequired, KeysOptional). | |
117 | ||
118 | -spec validate_unique_presence(t(K, _V), [K], [K]) -> | |
119 | hope_result:t(ok, [presence_error(K)]). | |
120 | validate_unique_presence(T, KeysRequired, KeysOptional) -> | |
121 | KeysSupported = KeysRequired ++ KeysOptional, | |
122 | KeysGiven = [K || {K, _V} <- T], | |
123 | KeysGivenUnique = lists:usort(KeysGiven), | |
124 | KeysDups = lists:usort(KeysGiven -- KeysGivenUnique), | |
125 | KeysMissing = KeysRequired -- KeysGivenUnique, | |
126 | KeysUnsupported = KeysGivenUnique -- KeysSupported, | |
127 | case {KeysDups, KeysMissing, KeysUnsupported} | |
128 | of {[], [], []} -> | |
129 | {ok, ok} | |
130 | ; {Dups, Missing, Unsupported} -> | |
131 | ErrorDups = | |
132 | case Dups | |
133 | of [] -> [] | |
134 | ; [_|_] -> [{keys_duplicated, Dups}] | |
135 | end, | |
136 | ErrorMissing = | |
137 | case Missing | |
138 | of [] -> [] | |
139 | ; [_|_] -> [{keys_missing, Missing}] | |
140 | end, | |
141 | ErrorUnsupported = | |
142 | case Unsupported | |
143 | of [] -> [] | |
144 | ; [_|_] -> [{keys_unsupported, Unsupported}] | |
145 | end, | |
146 | Errors = ErrorDups ++ ErrorMissing ++ ErrorUnsupported, | |
147 | {error, Errors} | |
148 | end. | |
149 | ||
03ac148f SK |
150 | |
151 | %% ============================================================================ | |
152 | %% Helpers | |
153 | %% ============================================================================ | |
154 | ||
48371999 SK |
155 | -spec lift_map(F) -> |
156 | G | |
157 | when F :: fun(( K, V1 ) -> V2) | |
158 | , G :: fun(({K, V1}) -> V2) | |
159 | . | |
d10156b0 SK |
160 | lift_map(F) -> |
161 | fun (X) -> apply_map(F, X) end. | |
162 | ||
48371999 SK |
163 | -spec apply_map(fun((K, V1) -> V2), {K, V1}) -> |
164 | V2. | |
d10156b0 SK |
165 | apply_map(F, {K, V}) -> |
166 | F(K, V). |