json2: refactoring and fixes (#16893)

vlib/x/json2/encode_struct_test.v

@@ -91,6 +91,18 @@ fn test_option_types() {
 	assert json.encode(StructTypeOption[time.Time]{}) == '{}'
 	assert json.encode(StructTypeOption[time.Time]{ val: time.Time{} }) == '{"val":"0000-00-00T00:00:00.000Z"}'
 	assert json.encode(StructTypeOption[time.Time]{ val: fixed_time }) == '{"val":"2022-03-11T13:54:25.000Z"}'
+
+	assert json.encode(StructTypeOption[StructType[int]]{
+		val: StructType[int]{
+			val: 1
+		}
+	}) == '{"val":{"val":1}}'
+
+	assert json.encode(StructTypeOption[Enumerates]{}) == '{}'
+	// assert json.encode(StructTypeOption[Enumerates]{ val: Enumerates.a }) == '{"val":0}'
+	// assert json.encode(StructTypeOption[Enumerates]{ val: Enumerates.d }) == '{"val":3}'
+	// assert json.encode(StructTypeOption[Enumerates]{ val: Enumerates.e }) == '{"val":99}'
+	// assert json.encode(StructTypeOption[Enumerates]{ val: Enumerates.f }) == '{"val":100}'
 }
 
 fn test_array() {

vlib/x/json2/encoder.v

@@ -149,8 +149,7 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 	mut i := 0
 	mut fields_len := 0
 	$for field in U.fields {
-		value := val.$(field.name)
+		if val.$(field.name).str() != 'Option(error: none)' {
-		if value.str() != 'Option(error: none)' {
 			fields_len++
 		}
 	}
@@ -181,35 +180,24 @@ fn (e &Encoder) encode_struct[U](val U, level int, mut wr io.Writer) ! {
 				}
 
 				$if field.typ is ?string {
-					option_value := val.$(field.name) as ?string
+					e.encode_string(val.$(field.name) ?.str()#[8..-2], mut wr)!
-					e.encode_string(option_value, mut wr)!
+				} $else $if field.typ is ?bool || field.typ is ?f32 || field.typ is ?f64
-				} $else $if field.typ is ?bool {
+					|| field.typ is ?i8 || field.typ is ?i16 || field.typ is ?int
-					option_value := val.$(field.name) as ?bool
+					|| field.typ is ?i64 || field.typ is ?u8 || field.typ is ?u16
-					wr.write(Any(option_value).str().bytes())!
+					|| field.typ is ?u32 || field.typ is ?u64 {
-				} $else $if field.typ is ?f32 {
+					wr.write(val.$(field.name) ?.str()#[7..-1].bytes())!
-					option_value := val.$(field.name) as ?f32
-					wr.write(Any(option_value).str().bytes())!
-				} $else $if field.typ is ?f64 {
-					option_value := val.$(field.name) as ?f64
-					wr.write(Any(option_value).str().bytes())!
-				} $else $if field.typ is ?i8 {
-					option_value := val.$(field.name) as ?i8
-					wr.write(Any(option_value).str().bytes())!
-				} $else $if field.typ is ?i16 {
-					option_value := val.$(field.name) as ?i16
-					wr.write(Any(option_value).str().bytes())!
-				} $else $if field.typ is ?int {
-					option_value := val.$(field.name) as ?int
-					wr.write(Any(option_value).int().str().bytes())!
 				} $else $if field.typ is ?time.Time {
 					option_value := val.$(field.name) as ?time.Time
 					parsed_time := option_value as time.Time
 					e.encode_string(parsed_time.format_rfc3339(), mut wr)!
 				} $else $if field.is_array {
 					e.encode_array(value, level + 1, mut wr)!
+				} $else $if field.is_struct {
+					e.encode_struct(value, level + 1, mut wr)!
 				} $else $if field.is_enum {
-					option_value := val.$(field.name) as ?int
+					// FIXME - checker and cast error
-					wr.write(Any(option_value).int().str().bytes())!
+					// wr.write(int(val.$(field.name)?).str().bytes())!
+					return error('type ${typeof(val).name} cannot be encoded yet')
 				} $else $if field.is_alias {
 					match field.unaliased_typ {
 						typeof[string]().idx {