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13285 :: using => with {.async.}

• martinc (orginal) [2025-08-02T18:54:21+02:00] view original

  Hello everyone! I'm trying to use the => macro from std/sugar like so (example is from a project using prologue):

  
  app.addRoute("/{path}$", (ctx) {.async.} => getPage(ctx, config), HttpGet)
  Run

  addRoute expects an async proc, hence the {.async.} pragma. The problem is that this fails to compile with the error Expected return type of 'Future' got 'auto' Now if explicitly define the proc like so, it works.

  
  proc pageHandler(ctx: Context) {.async.} =
      getPage(ctx, config)
  Run

  So is there a way to explicitly set the return type to Future[void] when using =>?

  Thanks!

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• stoking (orginal) [2025-08-02T19:48:28+02:00] view original

  Try this

  
  (ctx) {.async.} -> Future[void] => getPage(ctx, config)
  Run

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• martinc (orginal) [2025-08-02T20:16:25+02:00] view original

  Thanks! That almost worked, I had to modify to this:

  
  (ctx: Context) {.async.} -> Future[void] => await getPage(ctx)
  Run

  I assume I could create a PR to update the documentation?

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• Hobbyman (orginal) [2025-08-05T18:36:30+02:00] view original

  It looks cool but do these symbols have a defined and consistent meaning in all use-cases across the language or are they just private applications / fetishes, infrequently used and obfuscating the language...(?)

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