toml: fix @[toml: ], support @[skip] (#21571)

vlib/toml/tests/toml_attrs_test.v

@@ -0,0 +1,15 @@
+import toml
+
+struct TestStruct {
+	foo int
+	bar bool   @[skip]
+	baz string = 'def' @[toml: barbaz]
+}
+
+fn test_toml_attr_encode() {
+	assert toml.encode(TestStruct{}) == 'foo = 0\nbarbaz = "def"'
+}
+
+fn test_toml_attr_decode() {
+	assert toml.decode[TestStruct]('foo = 0\nbarbaz = "def"')! == TestStruct{}
+}

vlib/toml/toml.v

@@ -33,7 +33,19 @@ pub fn decode[T](toml_txt string) !T {
 
 fn decode_struct[T](doc Any, mut typ T) {
 	$for field in T.fields {
-		value := doc.value(field.name)
+		mut field_name := field.name
+		mut skip := false
+		for attr in field.attrs {
+			if attr == 'skip' {
+				skip = true
+				break
+			}
+			if attr.starts_with('toml:') {
+				field_name = attr.all_after(':').trim_space()
+			}
+		}
+		if !skip {
+			value := doc.value(field_name)
 			$if field.is_enum {
 				typ.$(field.name) = value.int()
 			} $else $if field.typ is string {
@@ -81,32 +93,38 @@ fn decode_struct[T](doc Any, mut typ T) {
 					// |k, v| k, v.int()
 					// Unfortunately lambdas have issues with multiple return at the time of writing
 					map[string]int {
-					typ.$(field.name) = maps.to_map[string, Any, string, int](mmap, fn (k string, v Any) (string, int) {
+						typ.$(field.name) = maps.to_map[string, Any, string, int](mmap,
+							fn (k string, v Any) (string, int) {
 							return k, v.int()
 						})
 					}
 					map[string]i64 {
-					typ.$(field.name) = maps.to_map[string, Any, string, i64](mmap, fn (k string, v Any) (string, i64) {
+						typ.$(field.name) = maps.to_map[string, Any, string, i64](mmap,
+							fn (k string, v Any) (string, i64) {
 							return k, v.i64()
 						})
 					}
 					map[string]u64 {
-					typ.$(field.name) = maps.to_map[string, Any, string, u64](mmap, fn (k string, v Any) (string, u64) {
+						typ.$(field.name) = maps.to_map[string, Any, string, u64](mmap,
+							fn (k string, v Any) (string, u64) {
 							return k, v.u64()
 						})
 					}
 					map[string]f32 {
-					typ.$(field.name) = maps.to_map[string, Any, string, f32](mmap, fn (k string, v Any) (string, f32) {
+						typ.$(field.name) = maps.to_map[string, Any, string, f32](mmap,
+							fn (k string, v Any) (string, f32) {
 							return k, v.f32()
 						})
 					}
 					map[string]f64 {
-					typ.$(field.name) = maps.to_map[string, Any, string, f64](mmap, fn (k string, v Any) (string, f64) {
+						typ.$(field.name) = maps.to_map[string, Any, string, f64](mmap,
+							fn (k string, v Any) (string, f64) {
 							return k, v.f64()
 						})
 					}
 					map[string]bool {
-					typ.$(field.name) = maps.to_map[string, Any, string, bool](mmap, fn (k string, v Any) (string, bool) {
+						typ.$(field.name) = maps.to_map[string, Any, string, bool](mmap,
+							fn (k string, v Any) (string, bool) {
 							return k, v.bool()
 						})
 					}
@@ -117,12 +135,14 @@ fn decode_struct[T](doc Any, mut typ T) {
 						})
 					}
 					map[string]Date {
-					typ.$(field.name) = maps.to_map[string, Any, string, Date](mmap, fn (k string, v Any) (string, Date) {
+						typ.$(field.name) = maps.to_map[string, Any, string, Date](mmap,
+							fn (k string, v Any) (string, Date) {
 							return k, v.date()
 						})
 					}
 					map[string]Time {
-					typ.$(field.name) = maps.to_map[string, Any, string, Time](mmap, fn (k string, v Any) (string, Time) {
+						typ.$(field.name) = maps.to_map[string, Any, string, Time](mmap,
+							fn (k string, v Any) (string, Time) {
 							return k, v.time()
 						})
 					}
@@ -135,6 +155,7 @@ fn decode_struct[T](doc Any, mut typ T) {
 			}
 		}
 	}
+}
 
 // encode encodes the type `T` into a TOML string.
 // If `T` has a custom `.to_toml()` method, it will be used instead of the default.
@@ -151,7 +172,20 @@ pub fn encode[T](typ T) string {
 fn encode_struct[T](typ T) map[string]Any {
 	mut mp := map[string]Any{}
 	$for field in T.fields {
-		mp[field.name] = to_any(typ.$(field.name))
+		mut skip := false
+		mut field_name := field.name
+		for attr in field.attrs {
+			if attr == 'skip' {
+				skip = true
+				break
+			}
+			if attr.starts_with('toml:') {
+				field_name = attr.all_after(':').trim_space()
+			}
+		}
+		if !skip {
+			mp[field_name] = to_any(typ.$(field.name))
+		}
 	}
 	return mp
 }