Use an xref for Fetch -> Digest.

science/dataclass/reflect.py

@@ -70,6 +70,7 @@ class ClassMetadata:
 
 @dataclass_transform()
 def documented_dataclass(
+    doc: str = "",
     *,
     alias: str | None = None,
     init: bool = True,
@@ -99,6 +100,8 @@ def wrapper(cls: type[_T]) -> type[_D]:
                 weakref_slot=weakref_slot,
             )(cls),
         )
+        if doc:
+            data_type.__doc__ = doc
         return document_dataclass(data_type, ClassMetadata(alias=alias))
 
     return wrapper

science/model.py

@@ -62,17 +62,19 @@ def lazy(self) -> bool:
     source_type: ClassVar[str] = "binding"
 
 
-@documented_dataclass(frozen=True, alias="source")
-class Fetch:
-    """Source a file by fetching it from the internet at scie run-time or scie build-time.
+@documented_dataclass(
+    f"""Source a file by fetching it from the internet at scie run-time or scie build-time.
 
-    ```{important}
-    If the file that is being sourced has a `digest` defined, the fetched content will be checked
-    against the specified digest and a mismatch will lead to an error. Without a digest defined the
-    content of the fetched file will be used as-is!
+    ```{{important}}
+    If the file that is being sourced has a [digest](#{Ref(Digest)}) defined, the fetched
+    content will be checked against the specified digest and a mismatch will lead to an error.
+    Without a digest defined the content of the fetched file will be used as-is!
     ```
-    """
-
+    """,
+    frozen=True,
+    alias="source",
+)
+class Fetch:
     url: Url = dataclasses.field(metadata=metadata("The URL of the file content to fetch."))
     lazy: bool = dataclasses.field(
         default=True,