feat: add ParseAs and NewSchema generics

Assisted-by: GLM 5.3 Flash

interpres.go

@@ -270,6 +270,36 @@ func Unmarshal(data []byte, v any) error {
 	return UnmarshalContext(context.Background(), data, v)
 }
 
+// ParseAs decodes a TOML document into T in one call, the generic shorthand
+// for Unmarshal with a destination variable:
+//
+//	cfg, err := interpres.ParseAs[Config](data)
+//
+// The zero T comes back with the error.
+func ParseAs[T any](data []byte) (T, error) {
+	var v T
+	err := Unmarshal(data, &v)
+	return v, err
+}
+
+// NewSchema precompiles the codec for T: the struct schema both directions
+// walk and the interface flags the decoder and the encoder resolve through
+// are built once and cached, so the first document pays the cost instead of
+// the hot path. A T that is not a struct warms nothing; there is nothing to
+// precompute for a map or a slice.
+func NewSchema[T any]() {
+	t := reflect.TypeFor[T]()
+	if t.Kind() != reflect.Struct {
+		return
+	}
+	cachedStructSchema(t)
+	_ = typeFlags(t)
+	_ = encTypeFlags(t)
+	pt := reflect.PointerTo(t)
+	_ = typeFlags(pt)
+	_ = encTypeFlags(pt)
+}
+
 // UnmarshalContext is the cancellable variant of Unmarshal.
 func UnmarshalContext(ctx context.Context, data []byte, v any) error {
 	// Only a destination that can reach an OrderedMap needs the node tree the