1package stdlib 2 3import ( 4 "github.com/zclconf/go-cty/cty" 5 "github.com/zclconf/go-cty/cty/function" 6 "github.com/zclconf/go-cty/cty/json" 7) 8 9var JSONEncodeFunc = function.New(&function.Spec{ 10 Params: []function.Parameter{ 11 { 12 Name: "val", 13 Type: cty.DynamicPseudoType, 14 AllowDynamicType: true, 15 AllowNull: true, 16 }, 17 }, 18 Type: function.StaticReturnType(cty.String), 19 Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { 20 val := args[0] 21 if !val.IsWhollyKnown() { 22 // We can't serialize unknowns, so if the value is unknown or 23 // contains any _nested_ unknowns then our result must be 24 // unknown. 25 return cty.UnknownVal(retType), nil 26 } 27 28 if val.IsNull() { 29 return cty.StringVal("null"), nil 30 } 31 32 buf, err := json.Marshal(val, val.Type()) 33 if err != nil { 34 return cty.NilVal, err 35 } 36 37 return cty.StringVal(string(buf)), nil 38 }, 39}) 40 41var JSONDecodeFunc = function.New(&function.Spec{ 42 Params: []function.Parameter{ 43 { 44 Name: "str", 45 Type: cty.String, 46 }, 47 }, 48 Type: func(args []cty.Value) (cty.Type, error) { 49 str := args[0] 50 if !str.IsKnown() { 51 return cty.DynamicPseudoType, nil 52 } 53 54 buf := []byte(str.AsString()) 55 return json.ImpliedType(buf) 56 }, 57 Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) { 58 buf := []byte(args[0].AsString()) 59 return json.Unmarshal(buf, retType) 60 }, 61}) 62 63// JSONEncode returns a JSON serialization of the given value. 64func JSONEncode(val cty.Value) (cty.Value, error) { 65 return JSONEncodeFunc.Call([]cty.Value{val}) 66} 67 68// JSONDecode parses the given JSON string and, if it is valid, returns the 69// value it represents. 70// 71// Note that applying JSONDecode to the result of JSONEncode may not produce 72// an identically-typed result, since JSON encoding is lossy for cty Types. 73// The resulting value will consist only of primitive types, object types, and 74// tuple types. 75func JSONDecode(str cty.Value) (cty.Value, error) { 76 return JSONDecodeFunc.Call([]cty.Value{str}) 77} 78