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1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file | |
2 // for details. All rights reserved. Use of this source code is governed by a | |
3 // BSD-style license that can be found in the LICENSE file. | |
4 | |
5 | |
6 class A { | |
7 int value; | |
8 A(this.value); | |
9 void set(int value) { this.value = value; } | |
10 int get() => value; | |
11 int operator[](int index) => value + index; | |
12 void operator[]=(int index, int newValue) { value += -index + newValue; } | |
13 void test(int expected) { | |
14 Expect.equals(expected, value); | |
15 } | |
16 Function limp(int n) { | |
17 if (n == 0) return set; | |
18 return () => limp(n - 1); | |
19 } | |
20 A get self() => this; | |
21 A operator+(A other) { | |
22 this.value += other.value; | |
23 return this; | |
24 } | |
25 } | |
26 | |
27 class Box { | |
28 A value; | |
29 Box(this.value); | |
30 A operator[](int pos) => value; | |
31 void operator[]=(int pos, A a) { value = a; } | |
32 A get x() => value; | |
33 void set x(A a) { value = a; } | |
34 } | |
35 | |
36 // Subset of grammar being tested. | |
37 // | |
38 // expression: | |
39 // assignableExpression assignmentOperator expression | |
40 // | conditionalExpression cascadeSection* | |
41 // ; | |
42 // expressionWithoutCascade: | |
43 // assignableExpression assignmentOperator expressionWithoutCascade | |
44 // | conditionalExpression | |
45 // ; | |
46 // expressionList: | |
47 // expression (',' expression)* | |
48 // ; | |
49 // assignableExpression: | |
50 // primary (arguments* assignableSelector)+ | |
51 // | super assignableSelector | |
52 // | identifier | |
53 // ; | |
54 // conditionalExpression: | |
55 // logicalOrExpression ('?' expressionWithoutCascade ':' expressionWithoutCa
scade)? | |
56 // ; | |
57 // primary: | |
58 // thisExpression | |
59 // | super assignableSelector | |
60 // | functionExpression | |
61 // | literal | |
62 // | identifier | |
63 // | newExpression | |
64 // | constObjectExpression | |
65 // | '(' expression ')' | |
66 // ; | |
67 // assignableSelector: | |
68 // '[' expression ']' | |
69 // | '.' identifier | |
70 // ; | |
71 // | |
72 // In words: | |
73 // An assignableExpression is either a variable or something ending in | |
74 // [expression] or .identifier. | |
75 | |
76 main() { | |
77 A a = new A(42); | |
78 A original = a; | |
79 A b = new A(87); | |
80 fa() => a; | |
81 Box box = new Box(a); | |
82 // Different expressions on the left-hand side of '..'. | |
83 // conditionalExpression >> postfixExpression > primary selector* | |
84 Expect.equals(a, a..set(37)..get()); | |
85 a.test(37); | |
86 Expect.equals(a, fa()..set(42)..get()); | |
87 a.test(42); | |
88 Expect.equals(a, box.x..set(37)..get()); | |
89 a.test(37); | |
90 // '..' binds to 'b + a', i.e., to the 'b' object, not to 'a'. | |
91 Expect.equals(b, b + a..test(124)..set(117)..get()); | |
92 b.test(117); | |
93 a.test(37); | |
94 | |
95 // expression :: conditionalExpression cascadeSection | |
96 // and conditionalExpression ends in expressionWithoutCascade. | |
97 // I.e., '..' binds to the entire condition expression, not to 'b'. | |
98 (a.value == 37) ? a : b..set(42); | |
99 a.test(42); | |
100 | |
101 // This binds .. to 'a', not 'c=a', and performs assignment after reading | |
102 // c.get(). | |
103 A c = new A(21); | |
104 c = a..set(c.get()); // FAILING. | |
105 Expect.equals(a, c); | |
106 Expect.equals(original, a); | |
107 a.test(21); // Fails as 42 if above is parsed as (c = a)..set(c.get()). | |
108 | |
109 // Should be parsed as (box..x = (c = a))..x.test(21). | |
110 c = null; | |
111 box..x = c = a..x.test(21); | |
112 c.test(21); | |
113 // Other variants | |
114 c = null; | |
115 box..x = c = (a..test(21))..x.test(21); | |
116 c.test(21); | |
117 | |
118 c = null; | |
119 box..x = (c = a..test(21))..x.test(21); | |
120 c.test(21); | |
121 | |
122 // Should work the same: | |
123 (a..set(42))..test(42); | |
124 a..set(21)..test(21); | |
125 | |
126 c = null; | |
127 Box originalBox = box; | |
128 // Should parse as: | |
129 // box = (box..x = (a.value == 21 ? b : c)..x.test(117)); | |
130 box = box..x = a.value == 21 ? b : c..x.test(117); | |
131 Expect.equals(originalBox, box); | |
132 Expect.equals(box.value, b); | |
133 | |
134 // New cascades are allowed inside an expressionWithoutCascade if properly | |
135 // delimited. | |
136 box..x = (a..set(42)..test(42))..x.test(42); | |
137 } | |
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