1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
|
-module(contracts_with_subtypes).
-compile(export_all).
%===============================================================================
-spec extract() -> 'ok'.
extract() ->
case dz_extract() of
{ok, Val} -> Val;
error -> exit(boom)
end.
-spec dz_extract() -> RetValue when
FileList :: something,
RetValue :: {ok, FileList} | error.
dz_extract() -> get(foo).
%-------------------------------------------------------------------------------
-spec extract2() -> 'ok'.
extract2() ->
case dz_extract2() of
{ok, Val} -> Val;
error -> exit(boom)
end.
-spec dz_extract2() -> RetValue when
RetValue :: {ok, FileList} | error,
FileList :: something.
dz_extract2() -> get(foo).
%===============================================================================
-spec foo1(Arg1) -> Res when
Arg1 :: atom(),
Res :: atom().
foo1(X) -> X.
-spec foo2(Arg1) -> Res when
Arg1 :: Arg2,
Arg2 :: atom(),
Res :: atom().
foo2(X) -> X.
-spec foo3(Arg1) -> Res when
Arg2 :: atom(),
Arg1 :: Arg2,
Res :: atom().
foo3(X) -> X.
-spec foo4(Type) -> Type when is_subtype(Type, atom()).
foo4(X) -> X.
-spec foo5(Type :: atom()) -> Type :: atom().
foo5(X) -> X.
-spec foo6(Type) -> Type when Type :: atom().
foo6(X) -> X.
-spec foo7(Type) -> Type.
foo7(X) -> X.
%-------------------------------------------------------------------------------
bar(1) -> foo1(5);
bar(2) -> foo2(5);
bar(3) -> foo3(5);
bar(4) -> foo4(5);
bar(5) -> foo5(5);
bar(6) -> foo6(5);
bar(7) -> foo7(5).
wrong_foo6() ->
b = foo6(a).
%===============================================================================
-spec rec_arg(Arg) -> ok when
Arg :: {a, A} | {b, B},
A :: a | {b, B},
B :: b | {a, A}.
rec_arg(X) -> get(X).
c(aa) -> rec_arg({a, a});
c(bb) -> rec_arg({b, b});
c(abb) -> rec_arg({a, {b, b}});
c(baa) -> rec_arg({b, {a, a}});
c(abaa) -> rec_arg({a, {b, {a, a}}});
c(babb) -> rec_arg({b, {a, {b, b}}});
c(ababb) -> rec_arg({a, {b, {a, {b, b}}}});
c(babaa) -> rec_arg({b, {a, {b, {a, a}}}}).
w(ab) -> rec_arg({a, b}); % breaks the contract
w(ba) -> rec_arg({b, a}); % breaks the contract
w(aba) -> rec_arg({a, {b, a}}); % no longer breaks the contract
w(bab) -> rec_arg({b, {a, b}}); % breaks the contract
w(abab) -> rec_arg({a, {b, {a, b}}}); % no longer breaks the contract
w(baba) -> rec_arg({b, {a, {b, a}}}); % no longer breaks the contract
w(ababa) -> rec_arg({a, {b, {a, {b, a}}}});
w(babab) -> rec_arg({b, {a, {b, {a, b}}}}).
%% For comparison: the same thing with types
-type ab() :: {a, a()} | {b, b()}.
-type a() :: a | {b, b()}.
-type b() :: b | {a, a()}.
-spec rec2(Arg) -> ok when
Arg :: ab().
rec2(X) -> get(X).
d(aa) -> rec2({a, a});
d(bb) -> rec2({b, b});
d(abb) -> rec2({a, {b, b}});
d(baa) -> rec2({b, {a, a}});
d(abaa) -> rec2({a, {b, {a, a}}});
d(babb) -> rec2({b, {a, {b, b}}});
d(ababb) -> rec2({a, {b, {a, {b, b}}}});
d(babaa) -> rec2({b, {a, {b, {a, a}}}}).
q(ab) -> rec2({a, b}); % breaks the contract
q(ba) -> rec2({b, a}); % breaks the contract
q(aba) -> rec2({a, {b, a}}); % breaks the contract
q(bab) -> rec2({b, {a, b}}); % breaks the contract
q(abab) -> rec2({a, {b, {a, b}}}); % breaks the contract
q(baba) -> rec2({b, {a, {b, a}}}); % breaks the contract
q(ababa) -> rec2({a, {b, {a, {b, a}}}}); % breaks the contract
q(babab) -> rec2({b, {a, {b, {a, b}}}}); % breaks the contract
q(ababab) -> rec2({a, {b, {a, {b, {a, b}}}}});
q(bababa) -> rec2({b, {a, {b, {a, {b, a}}}}});
q(abababa) -> rec2({a, {b, {a, {b, {a, {b, a}}}}}});
q(bababab) -> rec2({b, {a, {b, {a, {b, {a, b}}}}}}).
%===============================================================================
-type dublo(X) :: {X, X}.
-type weird(X,Y) :: {X, Y, X, X}.
-spec forfun(dublo(Var)) -> ok when Var :: atom().
forfun(_) -> ok.
-spec forfun2(weird(Var, Var)) -> ok when Var :: atom().
forfun2(_) -> ok.
%===============================================================================
-spec shallow(X) -> {ok, X} | {ok, X, file:filename()} | err1 | err2.
shallow(X) -> get(X).
st(X) when is_atom(X) ->
case shallow(X) of
err1 -> ok;
err2 -> ok;
{ok, X} -> ok;
{ok, X, Res} ->
case Res of
1 -> bad;
_Other -> ok
end;
alpha -> bad;
{ok, 42} -> ok;
42 -> bad
end.
%-------------------------------------------------------------------------------
-spec deep(X) -> Ret when
Ret :: {ok, X} | Err,
Err :: err1 | err2.
deep(X) -> get(X).
dt(X) when is_atom(X) ->
case deep(X) of
err1 -> ok;
err2 -> ok;
{ok, X} -> ok;
alpha -> bad;
{ok, 42} -> ok;
42 -> bad
end.
%-------------------------------------------------------------------------------
-type local_errors() :: err1 | err2.
-spec deep2(X) -> Ret when
Ret :: {ok, X} | Err,
Err :: local_errors().
deep2(X) -> get(X).
dt2(X) when is_atom(X) ->
case deep2(X) of
err1 -> ok;
err2 -> ok;
{ok, X} -> ok;
alpha -> bad;
{ok, 42} -> ok;
42 -> bad
end.
%-------------------------------------------------------------------------------
-spec deep3(X) -> Ret when
Ret :: {ok, X, file:filename()} | Err,
Err :: local_errors().
deep3(X) -> get(X).
dt3(X) when is_atom(X) ->
case deep3(X) of
err1 -> ok;
err2 -> ok;
{ok, X, Res} ->
case Res of
1 -> bad;
_Other -> ok
end;
{ok, X} -> bad;
alpha -> bad;
{ok, 42} -> bad;
42 -> bad
end.
%===============================================================================
-spec flat_ets_new(Name, Options) -> atom() when
Name :: atom(),
Options :: [Option],
Option :: set
| ordered_set
| bag
| duplicate_bag
| public
| protected
| private
| named_table
| {keypos, integer()}
| {heir, pid(), term()}
| {heir, none}
| {write_concurrency, boolean()}
| {read_concurrency, boolean()}
| compressed.
flat_ets_new(Name, Options) ->
get({Name, Options}).
flat_ets_new_t() ->
flat_ets_new(12,[]),
flat_ets_new({a,b},[]),
flat_ets_new(name,[foo]),
flat_ets_new(name,{bag}),
flat_ets_new(name,bag),
ok.
-type access() :: public | protected | private.
-type type() :: set | ordered_set | bag | duplicate_bag.
-spec factored_ets_new(Name, Options) -> atom() when
Name :: atom(),
Options :: [Option],
Option :: Type | Access | named_table | {keypos,Pos}
| {heir, Pid :: pid(), HeirData} | {heir, none} | Tweaks,
Type :: type(),
Access :: access(),
Tweaks :: {write_concurrency, boolean()}
| {read_concurrency, boolean()}
| compressed,
Pos :: pos_integer(),
HeirData :: term().
factored_ets_new(Name, Options) ->
get({Name, Options}).
factored_ets_new_t() ->
factored_ets_new(12,[]),
factored_ets_new({a,b},[]),
factored_ets_new(name,[foo]),
factored_ets_new(name,{bag}),
factored_ets_new(name,bag),
ok.
|
