github.com/Comcast/plax@v0.8.32/dsl/util.go (about) 1 /* 2 * Copyright 2021 Comcast Cable Communications Management, LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 * 16 * SPDX-License-Identifier: Apache-2.0 17 */ 18 19 package dsl 20 21 import ( 22 "encoding/json" 23 "fmt" 24 "strings" 25 26 "github.com/Comcast/plax/subst" 27 ) 28 29 func JSON(x interface{}) string { 30 js, err := subst.JSONMarshal(&x) 31 if err != nil { 32 js, _ = subst.JSONMarshal(map[string]interface{}{ 33 fmt.Sprintf("%T", x): fmt.Sprintf("%#v", x), 34 }) 35 } 36 return string(js) 37 } 38 39 func MaybeParseJSON(x interface{}) interface{} { 40 if s, is := x.(string); is { 41 var y interface{} 42 if err := json.Unmarshal([]byte(s), &y); err == nil { 43 return y 44 } 45 } 46 return x 47 } 48 49 func MaybeSerialize(x interface{}) (string, error) { 50 if s, is := x.(string); is { 51 return s, nil 52 } 53 js, err := json.Marshal(&x) 54 if err != nil { 55 // We still return something useful, but we also 56 // return the error. Probably dumb. 57 return JSON(map[string]interface{}{ 58 "error": err.Error(), 59 "on": fmt.Sprintf("%#v", x), 60 }), err 61 } 62 return string(js), nil 63 } 64 65 // Canon constructs a canonical (via JSON) representation. 66 func Canon(x interface{}) interface{} { 67 js, err := json.Marshal(&x) 68 if err != nil { 69 panic(err) 70 } 71 var y interface{} 72 if err = json.Unmarshal(js, &y); err != nil { 73 panic(err) 74 } 75 return y 76 } 77 78 // short returns a short version of the given string. 79 func short(s string) string { 80 limit := 30 81 s = strings.ReplaceAll(s, "\n", " ") 82 if limit < len(s)-3 { 83 return s[0:limit] + "..." 84 } 85 return s 86 } 87 88 // As is shameful. 89 func As(src interface{}, dst interface{}) error { 90 js, err := json.Marshal(&src) 91 if err != nil { 92 return err 93 } 94 return json.Unmarshal(js, &dst) 95 }