add json.encode method

examples/hello.ghost

@@ -1,16 +1 @@
-test = '{ "name": "Kai", "age": 34, "is_admin": true, "hobbies": ["programming", "gaming", "reading"], "address": { "street": "1234 Main St", "city": "Anytown", "state": "CA", "zip": 12345 } }'
-
-foo = json.parse(test)
-
-console.log(foo.name)
-console.log(foo.age)
-console.log(foo.is_admin)
-console.log(foo.hobbies)
-console.log(foo.address)
-console.log(foo.address.street)
-console.log(foo.address.city)
-console.log(foo.address.state)
-console.log(foo.address.zip)
-console.log(foo.hobbies[0])
-console.log(foo.hobbies[1])
-console.log(foo.hobbies[2])
+print("hello world!")

library/modules/json.go

@@ -2,6 +2,7 @@ package modules
 
 import (
 	"encoding/json"
+	"fmt"
 
 	"ghostlang.org/x/ghost/object"
 	"ghostlang.org/x/ghost/token"
@@ -12,7 +13,7 @@ var JsonProperties = map[string]*object.LibraryProperty{}
 
 func init() {
 	RegisterMethod(JsonMethods, "decode", jsonDecode)
-	// RegisterMethod(JsonMethods, "encode", jsonEncode)
+	RegisterMethod(JsonMethods, "encode", jsonEncode)
 }
 
 // jsonDecode decodes the JSON-encoded data and returns a new list or map object.
@@ -59,3 +60,51 @@ func jsonDecode(scope *object.Scope, tok token.Token, args ...object.Object) obj
 
 	return object.NewError("failed to decode JSON: %s", err.Error())
 }
+
+// jsonEncode returns the JSON encoding of either a list or map object.
+func jsonEncode(scope *object.Scope, tok token.Token, args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return object.NewError("wrong number of arguments. got=%d, want=1", len(args))
+	}
+
+	switch arg := args[0].(type) {
+	case *object.List:
+		var elements []interface{}
+
+		for _, val := range arg.Elements {
+			elements = append(elements, object.ObjectToAnyValue(val))
+		}
+
+		data, err := json.Marshal(elements)
+
+		if err != nil {
+			return object.NewError("failed to encode JSON: %s", err.Error())
+		}
+
+		return &object.String{Value: string(data)}
+	case *object.Map:
+		pairs := make(map[string]interface{})
+
+		for _, pair := range arg.Pairs {
+			// map keys can be numbers, strings, or booleans
+			switch pair.Key.(type) {
+			case *object.String:
+				pairs[pair.Key.(*object.String).Value] = object.ObjectToAnyValue(pair.Value)
+			case *object.Number:
+				pairs[fmt.Sprintf("%d", object.ObjectToAnyValue(pair.Key.(*object.Number)))] = object.ObjectToAnyValue(pair.Value)
+			case *object.Boolean:
+				pairs[fmt.Sprintf("%t", pair.Key.(*object.Boolean).Value)] = object.ObjectToAnyValue(pair.Value)
+			}
+		}
+
+		data, err := json.Marshal(pairs)
+
+		if err != nil {
+			return object.NewError("failed to encode JSON: %s", err.Error())
+		}
+
+		return &object.String{Value: string(data)}
+	}
+
+	return object.NewError("argument to `encode` must be LIST or MAP, got %s", args[0].Type())
+}

object/object.go

@@ -83,3 +83,41 @@ func AnyValueToObject(val any) Object {
 
 	return nil
 }
+
+func ObjectToAnyValue(val Object) any {
+	switch v := val.(type) {
+	case *Boolean:
+		return bool(v.Value)
+	case *String:
+		return string(v.Value)
+	case *Number:
+		// Determine if value is an integer or float.
+		if v.Value.Exponent() <= 0 {
+			return int(v.Value.IntPart())
+		}
+
+		num, _ := v.Value.Float64()
+
+		return num
+	case *Null:
+		return nil
+	case *List:
+		var collection []any
+
+		for _, val := range v.Elements {
+			collection = append(collection, ObjectToAnyValue(val))
+		}
+
+		return collection
+	case *Map:
+		collection := make(map[string]any)
+
+		for _, pair := range v.Pairs {
+			collection[pair.Key.(*String).Value] = ObjectToAnyValue(pair.Value)
+		}
+
+		return collection
+	}
+
+	return nil
+}