A bare def is answered with the let to write, and a generic missing its arrow is refused at the end of its line.

lib/indent_reader.ml

@@ -1544,6 +1544,18 @@ and header (s : st) w : Form.t =
     let head =
       match w with "def" -> "def" | "once" -> "defonce" | _ -> "defconst"
     in
+    if shown = "def" then
+      failk "def-is-let" l0
+        "a global is written with let, at the file's top level:\n\n    let %s%s%s"
+        (text_of name)
+        (match tyf, v with
+         | Some t, _ -> ": " ^ text_of t
+         | None, None -> ": i32"
+         | None, Some _ -> "")
+        (match v, tyf with
+         | Some v, _ -> " = " ^ text_of v
+         | None, None -> " = 0"
+         | None, Some _ -> "");
     let items =
       match w, tyf, v with
       | "const", None, Some v -> [ name; v ]
@@ -1560,12 +1572,6 @@ and header (s : st) w : Form.t =
            i32 = 0"
           shown (text_of name) shown (text_of name)
     in
-    if shown = "def" then
-      failk "def-is-let" l0
-        "a global is written with let, at the file's top level:\n\n    let %s%s%s"
-        (text_of name)
-        (match tyf with Some t -> ": " ^ text_of t | None -> "")
-        (match v with Some v -> " = " ^ text_of v | None -> "");
     named head items
   | "struct" | "union" ->
     let name = name_tok p ~what:"the type's name" in
@@ -1677,7 +1683,10 @@ and header (s : st) w : Form.t =
       match (peek p).tok with
       | NAME "->" -> ignore (advance p); ty p
       | _ ->
-        failk "generic-return" (where_ p)
+        (* At the end of the header's line, where the arrow goes. *)
+        let e = (last p).loc in
+        failk "generic-return"
+          { e with Loc.line = e.Loc.eline; col = e.Loc.ecol }
           "a %s states the type every method returns: %s %s(%s) -> dyn"
           w w (text_of name) names
     in

test/test_syntax.ml

@@ -582,6 +582,13 @@ let () =
   reads "a top-level let is a global" "let g = 1\nlet h: i32 = 2\nlet s: [4 u8]\nf(g)"
     "(def g dyn 1)\n(def h i32 2)\n(def s [4 u8])\n(f g)";
   refuses "def" "def g: i32 = 1" "indent/def-is-let" "let g: i32 = 1";
+  refuses "a bare def" "def g" "indent/def-is-let" "let g: i32 = 0";
+  (match read "generic f(a)\n\nfn g() = 1" with
+   | exception Loc.Error d when d.Loc.dloc.Loc.line = 1 && d.Loc.dloc.Loc.col = 13 -> ()
+   | exception Loc.Error d ->
+     fail "a generic with no arrow is refused at %d:%d, not at its line's end"
+       d.Loc.dloc.Loc.line d.Loc.dloc.Loc.col
+   | _ -> fail "a generic with no arrow was read");
   reads "a let in a comment block stays local" "comment:\n  let x = 1\n  f(x)"
     "(comment (let [x 1] (f x)))";
   reads "and in a fn" "fn f() -> i32\n  let x = 1\n  x" "(defn f [] i32 (let [x 1] x))";

web/examples/quotes.sh

@@ -81,10 +81,9 @@ do
   name=${pair%%:*}; src=${pair#*:}
   printf '%s\n' "$src" > "$here/.q.flan"
   out=$("$FLAN" check "$here/.q.flan" 2>&1)
-  # A probe that compiles is the failure this loop is most likely to meet, and
-  # it is the one that used to be unreadable: `flan check` answers a clean
-  # program with its whole symbol table, so the needle became eighty lines of
-  # prelude signatures and the diff said nothing. Say what actually happened.
+  # A probe that compiles is the failure this loop is most likely to meet:
+  # `flan check` prints nothing for it, so the needle would be empty and the
+  # diff would say nothing. Say what actually happened.
   if "$FLAN" check "$here/.q.flan" >/dev/null 2>&1; then
     echo "FAIL  message: $name"
     echo "      this program compiles now — the page still says it is refused"