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
|
=== tests/cases/conformance/types/typeRelationships/recursiveTypes/objectTypeWithRecursiveWrappedPropertyCheckedNominally.ts ===
// Types with infinitely expanding recursive types are type checked nominally
class List<T> {
>List : List<T>
data: T;
>data : T
next: List<List<T>>;
>next : List<List<T>>
}
class MyList<T> {
>MyList : MyList<T>
data: T;
>data : T
next: MyList<MyList<T>>;
>next : MyList<MyList<T>>
}
var list1 = new List<number>();
>list1 : List<number>
>new List<number>() : List<number>
>List : typeof List
var list2 = new List<string>();
>list2 : List<string>
>new List<string>() : List<string>
>List : typeof List
var myList1 = new MyList<number>();
>myList1 : MyList<number>
>new MyList<number>() : MyList<number>
>MyList : typeof MyList
var myList2 = new MyList<string>();
>myList2 : MyList<string>
>new MyList<string>() : MyList<string>
>MyList : typeof MyList
list1 = myList1; // error, not nominally equal
>list1 = myList1 : MyList<number>
>list1 : List<number>
>myList1 : MyList<number>
list1 = myList2; // error, type mismatch
>list1 = myList2 : MyList<string>
>list1 : List<number>
>myList2 : MyList<string>
list2 = myList1; // error, not nominally equal
>list2 = myList1 : MyList<number>
>list2 : List<string>
>myList1 : MyList<number>
list2 = myList2; // error, type mismatch
>list2 = myList2 : MyList<string>
>list2 : List<string>
>myList2 : MyList<string>
var rList1 = new List<List<number>>();
>rList1 : List<List<number>>
>new List<List<number>>() : List<List<number>>
>List : typeof List
var rMyList1 = new List<MyList<number>>();
>rMyList1 : List<MyList<number>>
>new List<MyList<number>>() : List<MyList<number>>
>List : typeof List
rList1 = rMyList1; // error, not nominally equal
>rList1 = rMyList1 : List<MyList<number>>
>rList1 : List<List<number>>
>rMyList1 : List<MyList<number>>
function foo<T extends List<number>, U extends MyList<number>>(t: T, u: U) {
>foo : <T extends List<number>, U extends MyList<number>>(t: T, u: U) => void
>t : T
>u : U
t = u; // error
>t = u : U
>t : T
>u : U
u = t; // error
>u = t : T
>u : U
>t : T
var a: List<number>;
>a : List<number>
var b: MyList<number>;
>b : MyList<number>
a = t; // ok
>a = t : T
>a : List<number>
>t : T
a = u; // error
>a = u : U
>a : List<number>
>u : U
b = t; // error
>b = t : T
>b : MyList<number>
>t : T
b = u; // ok
>b = u : U
>b : MyList<number>
>u : U
}
function foo2<T extends U, U extends MyList<number>>(t: T, u: U) {
>foo2 : <T extends U, U extends MyList<number>>(t: T, u: U) => void
>t : T
>u : U
t = u; // error
>t = u : U
>t : T
>u : U
u = t; // was error, ok after constraint made illegal, doesn't matter
>u = t : T
>u : U
>t : T
var a: List<number>;
>a : List<number>
var b: MyList<number>;
>b : MyList<number>
a = t; // error
>a = t : T
>a : List<number>
>t : T
a = u; // error
>a = u : U
>a : List<number>
>u : U
b = t; // ok
>b = t : T
>b : MyList<number>
>t : T
b = u; // ok
>b = u : U
>b : MyList<number>
>u : U
}
|
