Created
October 18, 2017 03:13
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Input processing logic as a partial function in Go.
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| package main | |
| import ( | |
| "fmt" | |
| "errors" | |
| ) | |
| type G interface{} | |
| type X struct { | |
| active bool | |
| } | |
| type Y struct { | |
| active bool | |
| } | |
| type _T interface { | |
| _T() | |
| } | |
| func (x X) _T() {} | |
| func (y Y) _T() {} | |
| type T struct { | |
| X | |
| Y | |
| } | |
| func encode(g G) T { | |
| switch g.(type) { | |
| case X: | |
| x := g.(X) | |
| x.active = true | |
| return T{X: x, Y: Y{}} | |
| case Y: | |
| y := g.(Y) | |
| y.active = true | |
| return T{X: X{}, Y: y} | |
| default: | |
| return T{} | |
| } | |
| } | |
| func decode(t T) _T { | |
| var i _T | |
| if t.X.active { | |
| if t.Y.active {panic("invalid input")} | |
| i = t.X | |
| } else | |
| if t.Y.active { | |
| i = t.Y | |
| } else { | |
| panic("unknown type") | |
| } | |
| return i | |
| } | |
| func logic(i _T) G { | |
| switch i.(type) { | |
| case X: | |
| return i.(X) | |
| case Y: | |
| return i.(Y) | |
| default: | |
| return errors.New("sorry, can't do") | |
| } | |
| } | |
| func main() { | |
| receive := func(t T) G { | |
| i := decode(t) | |
| return logic(i) | |
| } | |
| fmt.Printf("logic type %T\n", logic(X{})) | |
| fmt.Printf("logic type %T\n", logic(Y{})) | |
| fmt.Printf("receive type %T\n", receive(encode(X{}))) | |
| fmt.Printf("receive type %T\n", receive(encode(Y{}))) | |
| //fmt.Printf("type %T\n", f(T{})) | |
| } |
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