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03ac148f SK |
1 | %%%---------------------------------------------------------------------------- |
2 | %%% Equivalent to stdlib's orddict, but with a pretty (IMO), uniform interface. | |
3 | %%%---------------------------------------------------------------------------- | |
4 | -module(hope_kv_list). | |
5 | ||
465f1bde | 6 | -behavior(hope_gen_dictionary). |
03ac148f SK |
7 | |
8 | -export_type( | |
9 | [ t/2 | |
10 | ]). | |
11 | ||
12 | -export( | |
13 | [ empty/0 | |
14 | , get/2 | |
870172d6 | 15 | , get/3 |
03ac148f SK |
16 | , set/3 |
17 | , update/3 | |
70cf8e86 | 18 | , pop/2 |
03ac148f SK |
19 | , iter/2 |
20 | , map/2 | |
21 | , filter/2 | |
22 | , fold/3 | |
23 | , of_kv_list/1 | |
24 | , to_kv_list/1 | |
fa24061d SK |
25 | , validate_unique_presence/2 % Assume default optional parameter(s) |
26 | , validate_unique_presence/3 % Specify optional parameter(s) | |
03ac148f SK |
27 | ]). |
28 | ||
29 | ||
30 | -type t(K, V) :: | |
31 | [{K, V}]. | |
32 | ||
fa24061d SK |
33 | -type presence_error(A) :: |
34 | {keys_missing , [A]} | |
35 | | {keys_duplicated , [A]} | |
36 | | {keys_unsupported , [A]} | |
37 | . | |
38 | ||
03ac148f SK |
39 | |
40 | %% ============================================================================ | |
41 | %% API | |
42 | %% ============================================================================ | |
43 | ||
44 | -spec empty() -> | |
45 | []. | |
46 | empty() -> | |
47 | []. | |
48 | ||
95c3c2a7 PO |
49 | -spec get(t(K, V), K) -> |
50 | hope_option:t(V). | |
03ac148f SK |
51 | get(T, K) -> |
52 | case lists:keyfind(K, 1, T) | |
53 | of false -> none | |
54 | ; {K, V} -> {some, V} | |
55 | end. | |
56 | ||
870172d6 SK |
57 | -spec get(t(K, V), K, V) -> |
58 | V. | |
59 | get(T, K, Default) -> | |
60 | Vopt = get(T, K), | |
61 | hope_option:get(Vopt, Default). | |
62 | ||
95c3c2a7 PO |
63 | -spec set(t(K, V), K, V) -> |
64 | t(K, V). | |
03ac148f SK |
65 | set(T, K, V) -> |
66 | lists:keystore(K, 1, T, {K, V}). | |
67 | ||
95c3c2a7 PO |
68 | -spec update(t(K, V), K, fun((hope_option:t(V)) -> V)) -> |
69 | t(K, V). | |
03ac148f SK |
70 | update(T, K, F) -> |
71 | V1Opt = get(T, K), | |
72 | V2 = F(V1Opt), | |
37c6e98b | 73 | % TODO: Eliminate the 2nd lookup. |
03ac148f SK |
74 | set(T, K, V2). |
75 | ||
95c3c2a7 PO |
76 | -spec pop(t(K, V), K) -> |
77 | {hope_option:t(V), t(K, V)}. | |
70cf8e86 SK |
78 | pop(T1, K) -> |
79 | case lists:keytake(K, 1, T1) | |
80 | of {value, {K, V}, T2} -> {{some, V}, T2} | |
81 | ; false -> {none , T1} | |
82 | end. | |
83 | ||
95c3c2a7 PO |
84 | -spec iter(t(K, V), fun((K, V) -> ok)) -> |
85 | ok. | |
c1672ac4 | 86 | iter(T, F1) -> |
d10156b0 | 87 | F2 = lift_map(F1), |
c1672ac4 | 88 | lists:foreach(F2, T). |
03ac148f | 89 | |
95c3c2a7 PO |
90 | -spec map(t(K, V), fun((K, V) -> V)) -> |
91 | t(K, V). | |
c1672ac4 | 92 | map(T, F1) -> |
d10156b0 SK |
93 | F2 = fun ({K, _}=X) -> {K, apply_map(F1, X)} end, |
94 | lists:map(F2, T). | |
03ac148f | 95 | |
95c3c2a7 PO |
96 | -spec filter(t(K, V), fun((K, V) -> boolean())) -> |
97 | t(K, V). | |
c1672ac4 | 98 | filter(T, F1) -> |
d10156b0 | 99 | F2 = lift_map(F1), |
c1672ac4 | 100 | lists:filter(F2, T). |
03ac148f | 101 | |
95c3c2a7 PO |
102 | -spec fold(t(K, V), fun((K, V, Acc) -> Acc), Acc) -> |
103 | Acc. | |
03ac148f SK |
104 | fold(T, F1, Accumulator) -> |
105 | F2 = fun ({K, V}, Acc) -> F1(K, V, Acc) end, | |
097a2aa3 | 106 | lists:foldl(F2, Accumulator, T). |
03ac148f | 107 | |
95c3c2a7 PO |
108 | -spec to_kv_list(t(K, V)) -> |
109 | [{K, V}]. | |
03ac148f SK |
110 | to_kv_list(T) -> |
111 | T. | |
112 | ||
95c3c2a7 PO |
113 | -spec of_kv_list([{K, V}]) -> |
114 | t(K, V). | |
03ac148f | 115 | of_kv_list(List) -> |
37c6e98b | 116 | % TODO: Decide if validation is to be done here. Do so if yes. |
03ac148f SK |
117 | List. |
118 | ||
fa24061d SK |
119 | -spec validate_unique_presence(t(K, _V), [K]) -> |
120 | hope_result:t(ok, [presence_error(K)]). | |
121 | validate_unique_presence(T, KeysRequired) -> | |
122 | KeysOptional = [], | |
123 | validate_unique_presence(T, KeysRequired, KeysOptional). | |
124 | ||
125 | -spec validate_unique_presence(t(K, _V), [K], [K]) -> | |
126 | hope_result:t(ok, [presence_error(K)]). | |
127 | validate_unique_presence(T, KeysRequired, KeysOptional) -> | |
128 | KeysSupported = KeysRequired ++ KeysOptional, | |
129 | KeysGiven = [K || {K, _V} <- T], | |
130 | KeysGivenUnique = lists:usort(KeysGiven), | |
131 | KeysDups = lists:usort(KeysGiven -- KeysGivenUnique), | |
132 | KeysMissing = KeysRequired -- KeysGivenUnique, | |
133 | KeysUnsupported = KeysGivenUnique -- KeysSupported, | |
134 | case {KeysDups, KeysMissing, KeysUnsupported} | |
135 | of {[], [], []} -> | |
136 | {ok, ok} | |
137 | ; {Dups, Missing, Unsupported} -> | |
138 | ErrorDups = | |
139 | case Dups | |
140 | of [] -> [] | |
141 | ; [_|_] -> [{keys_duplicated, Dups}] | |
142 | end, | |
143 | ErrorMissing = | |
144 | case Missing | |
145 | of [] -> [] | |
146 | ; [_|_] -> [{keys_missing, Missing}] | |
147 | end, | |
148 | ErrorUnsupported = | |
149 | case Unsupported | |
150 | of [] -> [] | |
151 | ; [_|_] -> [{keys_unsupported, Unsupported}] | |
152 | end, | |
153 | Errors = ErrorDups ++ ErrorMissing ++ ErrorUnsupported, | |
154 | {error, Errors} | |
155 | end. | |
156 | ||
03ac148f SK |
157 | |
158 | %% ============================================================================ | |
159 | %% Helpers | |
160 | %% ============================================================================ | |
161 | ||
48371999 SK |
162 | -spec lift_map(F) -> |
163 | G | |
164 | when F :: fun(( K, V1 ) -> V2) | |
165 | , G :: fun(({K, V1}) -> V2) | |
166 | . | |
d10156b0 SK |
167 | lift_map(F) -> |
168 | fun (X) -> apply_map(F, X) end. | |
169 | ||
48371999 SK |
170 | -spec apply_map(fun((K, V1) -> V2), {K, V1}) -> |
171 | V2. | |
d10156b0 SK |
172 | apply_map(F, {K, V}) -> |
173 | F(K, V). |