Make TypeRenderer format-agnostic

tools/pony-doc/link_format.pony

@@ -0,0 +1,50 @@
+trait val LinkFormat
+  """
+  Format-specific behavior for cross-reference links and type parameter
+  brackets in type rendering.
+
+  TypeRenderer delegates link generation and bracket escaping to
+  implementations of this trait. Pass `None` instead of a `LinkFormat`
+  for plain-text output (no links, plain brackets).
+
+  Implementations must ensure that `link()` returns a string appropriate
+  for the output format. The returned string is embedded directly into the
+  rendered output — it must not contain characters that are syntactically
+  significant in the target format unless properly escaped.
+
+  `open_bracket()` and `close_bracket()` must return a visually paired
+  bracket pair suitable for delimiting type argument and type parameter
+  lists in linked contexts.
+  """
+  fun link(name: String, tqfn: String): String
+    """
+    Produce a cross-reference string linking `name` to the entity
+    identified by `tqfn`.
+    """
+
+  fun open_bracket(): String
+    """
+    Opening bracket for type argument and type parameter lists in linked
+    contexts.
+    """
+
+  fun close_bracket(): String
+    """
+    Closing bracket for type argument and type parameter lists in linked
+    contexts.
+    """
+
+primitive MkDocsLinkFormat is LinkFormat
+  """
+  Markdown link format for MkDocs documentation output.
+
+  Produces `[Name](tqfn.md)` cross-references and escaped brackets
+  `\[`/`\]` to avoid conflicts with markdown link syntax.
+  """
+
+  fun link(name: String, tqfn: String): String =>
+    "[" + name + "](" + tqfn + ".md)"
+
+  fun open_bracket(): String => "\\["
+
+  fun close_bracket(): String => "\\]"

tools/pony-doc/mk_docs_backend.pony

@@ -268,7 +268,7 @@ primitive MkDocsBackend is Backend
     content.append(
       TypeRenderer.render_type_params(
         entity.type_params,
-        true,
+        MkDocsLinkFormat,
         false,
         include_private))
     content.append(_source_link(entity.source, sanitized_pkg))
@@ -294,7 +294,7 @@ primitive MkDocsBackend is Backend
     content.append(
       TypeRenderer.render_type_params(
         entity.type_params,
-        false,
+        None,
         true,
         include_private))
     content.append(
@@ -303,7 +303,7 @@ primitive MkDocsBackend is Backend
         " is\n  ",
         ",\n  ",
         "",
-        false,
+        None,
         include_private))
     content.append("\n```\n\n")
 
@@ -316,7 +316,7 @@ primitive MkDocsBackend is Backend
           "#### Type Alias For\n\n* ",
           "\n* ",
           "\n\n---\n\n",
-          true,
+          MkDocsLinkFormat,
           include_private))
     else
       content.append(
@@ -325,7 +325,7 @@ primitive MkDocsBackend is Backend
           "#### Implements\n\n* ",
           "\n* ",
           "\n\n---\n\n",
-          true,
+          MkDocsLinkFormat,
           include_private))
     end
 
@@ -411,7 +411,7 @@ primitive MkDocsBackend is Backend
     result.append(
       TypeRenderer.render_type_params(
         method.type_params,
-        true,
+        MkDocsLinkFormat,
         false,
         include_private))
     result.append(_source_link(method.source, sanitized_pkg))
@@ -443,7 +443,7 @@ primitive MkDocsBackend is Backend
     result.append(
       TypeRenderer.render_type_params(
         method.type_params,
-        false,
+        None,
         true,
         include_private))
 
@@ -461,7 +461,7 @@ primitive MkDocsBackend is Backend
       result.append(
         TypeRenderer.render(
           param.param_type,
-          false,
+          None,
           true,
           include_private))
       match param.default_value
@@ -481,7 +481,7 @@ primitive MkDocsBackend is Backend
         result.append(
           TypeRenderer.render(
             rt,
-            false,
+            None,
             true,
             include_private))
       end
@@ -502,7 +502,7 @@ primitive MkDocsBackend is Backend
         result.append(
           TypeRenderer.render(
             param.param_type,
-            true,
+            MkDocsLinkFormat,
             true,
             include_private))
         match param.default_value
@@ -525,7 +525,7 @@ primitive MkDocsBackend is Backend
         result.append(
           TypeRenderer.render(
             rt,
-            true,
+            MkDocsLinkFormat,
             true,
             include_private))
       end
@@ -567,7 +567,7 @@ primitive MkDocsBackend is Backend
       result.append(
         TypeRenderer.render(
           field.field_type,
-          true,
+          MkDocsLinkFormat,
           false,
           include_private))
       result.append(_source_link(field.source, sanitized_pkg))