| 1 | package reflect |
|---|---|
| 2 | |
| 3 | // Not an actual implementation of DeepEqual. This is a model that supports |
| 4 | // the bare minimum needed to get through testing interp. |
| 5 | // |
| 6 | // Does not handle cycles. |
| 7 | // |
| 8 | // Note: unclear if reflect.go can support this. |
| 9 | func DeepEqual(x, y interface{}) bool { |
| 10 | if x == nil || y == nil { |
| 11 | return x == y |
| 12 | } |
| 13 | v1 := ValueOf(x) |
| 14 | v2 := ValueOf(y) |
| 15 | |
| 16 | return deepValueEqual(v1, v2, make(map[visit]bool)) |
| 17 | } |
| 18 | |
| 19 | // Key for the visitedMap in deepValueEqual. |
| 20 | type visit struct { |
| 21 | a1, a2 uintptr |
| 22 | typ Type |
| 23 | } |
| 24 | |
| 25 | func deepValueEqual(v1, v2 Value, visited map[visit]bool) bool { |
| 26 | if !v1.IsValid() || !v2.IsValid() { |
| 27 | return v1.IsValid() == v2.IsValid() |
| 28 | } |
| 29 | if v1.Type() != v2.Type() { |
| 30 | return false |
| 31 | } |
| 32 | |
| 33 | // Short circuit on reference types that can lead to cycles in comparison. |
| 34 | switch v1.Kind() { |
| 35 | case Pointer, Map, Slice, Interface: |
| 36 | k := visit{v1.Pointer(), v2.Pointer(), v1.Type()} // Not safe for moving GC. |
| 37 | if visited[k] { |
| 38 | // The comparison algorithm assumes that all checks in progress are true when it reencounters them. |
| 39 | return true |
| 40 | } |
| 41 | visited[k] = true |
| 42 | } |
| 43 | |
| 44 | switch v1.Kind() { |
| 45 | case Array: |
| 46 | for i := 0; i < v1.Len(); i++ { |
| 47 | if !deepValueEqual(v1.Index(i), v2.Index(i), visited) { |
| 48 | return false |
| 49 | } |
| 50 | } |
| 51 | return true |
| 52 | case Slice: |
| 53 | if v1.IsNil() != v2.IsNil() { |
| 54 | return false |
| 55 | } |
| 56 | if v1.Len() != v2.Len() { |
| 57 | return false |
| 58 | } |
| 59 | if v1.Pointer() == v2.Pointer() { |
| 60 | return true |
| 61 | } |
| 62 | for i := 0; i < v1.Len(); i++ { |
| 63 | if !deepValueEqual(v1.Index(i), v2.Index(i), visited) { |
| 64 | return false |
| 65 | } |
| 66 | } |
| 67 | return true |
| 68 | case Interface: |
| 69 | if v1.IsNil() || v2.IsNil() { |
| 70 | return v1.IsNil() == v2.IsNil() |
| 71 | } |
| 72 | return deepValueEqual(v1.Elem(), v2.Elem(), visited) |
| 73 | case Ptr: |
| 74 | if v1.Pointer() == v2.Pointer() { |
| 75 | return true |
| 76 | } |
| 77 | return deepValueEqual(v1.Elem(), v2.Elem(), visited) |
| 78 | case Struct: |
| 79 | for i, n := 0, v1.NumField(); i < n; i++ { |
| 80 | if !deepValueEqual(v1.Field(i), v2.Field(i), visited) { |
| 81 | return false |
| 82 | } |
| 83 | } |
| 84 | return true |
| 85 | case Map: |
| 86 | if v1.IsNil() != v2.IsNil() { |
| 87 | return false |
| 88 | } |
| 89 | if v1.Len() != v2.Len() { |
| 90 | return false |
| 91 | } |
| 92 | if v1.Pointer() == v2.Pointer() { |
| 93 | return true |
| 94 | } |
| 95 | for _, k := range v1.MapKeys() { |
| 96 | val1 := v1.MapIndex(k) |
| 97 | val2 := v2.MapIndex(k) |
| 98 | if !val1.IsValid() || !val2.IsValid() || !deepValueEqual(val1, val2, visited) { |
| 99 | return false |
| 100 | } |
| 101 | } |
| 102 | return true |
| 103 | case Func: |
| 104 | return v1.IsNil() && v2.IsNil() |
| 105 | default: |
| 106 | // Normal equality suffices |
| 107 | return v1.Interface() == v2.Interface() // try interface comparison as a fallback. |
| 108 | } |
| 109 | } |
| 110 |
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