pretty: improve block/proc-arg formatting

kernel/pretty.ay

@@ -180,6 +180,24 @@ Atomy AST open:
     grouped(n)
 
 
+  braces-block(contents, left = /empty) =
+    align(left <+> (lbrace <+> body(contents)) nest(2) <+> rbrace) <||>
+      if(left empty?)
+        then: align((lbrace <+> vbody(contents)) nest(2) <$> rbrace)
+        else: align(left <+> (lbrace <$> vbody(contents)) nest(2) <$> rbrace)
+
+  proc-arg(left, contents) =
+    if(from(.top)?)
+      then:
+        block =
+          (colon <+> body(contents)) <||>
+            (colon <$> vbody(contents))
+
+        align((left <> block) nest(2))
+      else:
+        braces-block(contents, left)
+
+
   /doc(b: Infix) :=
     from(.infix):
       ( if(b private)
@@ -189,31 +207,16 @@ Atomy AST open:
             unamb(b left) <+> text(b operator) <\> unamb(b right)
       ) hang(2)
 
-  /doc(b: Block) := do:
-    args =
+  /doc(b: Block) :=
+    braces-block(
+      b contents
       if(b arguments empty?)
         then: empty
-        else: list(render-sequence(b arguments))
-
-    contents = body(b contents)
-
-    align(args <+> (lbrace </> contents) nest(2) <\> rbrace)
+        else: list(render-sequence(b arguments)))
 
   /doc(c: Call) :=
     from(.call) { unamb(c name) } <> tupled(render-sequence(c arguments))
 
-  proc-arg(left, contents) =
-    if(from(.top)?)
-      then:
-        block =
-          (colon <+> body(contents)) <||>
-            (colon <$> vbody(contents))
-
-        align((left <> block) nest(2))
-      else:
-        align((left <+> lbrace <\> body(contents)) nest(2) <\> rbrace)
-
-
   /doc(`(~x [~*ys] { ~*zs })) :=
     proc-arg(
       from(.compose) { unamb(x) } <+>