feat: fail if suggestions is empty

thorimur · Sep 20, 2023 · d9abcff · d9abcff
1 parent ef6e153
commit d9abcff
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Showing 2 changed files with 5 additions and 0 deletions.
diff --git a/Std/Tactic/TryThis.lean b/Std/Tactic/TryThis.lean
@@ -428,6 +428,7 @@ The parameters are:
 def addSuggestions (ref : Syntax) (suggestions : Array Suggestion)
     (origSpan? : Option Syntax := none)
     (header : String := "Try these:") : MetaM Unit := do
+  if suggestions.isEmpty then throwErrorAt ref "no suggestions available"
   let msgs := suggestions.map toMessageData
   let msgs := msgs.foldl (init := MessageData.nil) (fun msg m => msg ++ m!"\n• " ++ m)
   logInfoAt ref m!"{header}{msgs}"

diff --git a/test/tryThis.lean b/test/tryThis.lean
@@ -186,3 +186,7 @@ info: Grab bag:
     postInfo? := " at 0.166667.",
     style? := some (.value (1/6))}
 ] with_header "Grab bag:"
+
+/-- error: no suggestions available -/
+#guard_msgs in
+#demo #[]