why does not this work?

[Jonatan Liljedahl]

This is version 2.5.18...

#(use-modules (ice-9 optargs))
#(define* (tempomark n t)
   (ly:export
      #{
         \once \override Score.MetronomeMark #'extra-offset = #'(-3 . 5)
         \tempo $n = $t
      #}
   )
)

But when I use this as #(tempomark 4 120) I get:

<string>:3:0: error: syntax error, unexpected $undefined:

;         \once \override Score.MetronomeMark #(quote extra-offset) =
#(quote (-3 . 5))

<string>:4:16: error: syntax error, unexpected NUMBER_IDENTIFIER,
expecting DIGIT or UNSIGNED or DURATION_IDENTIFIER:
         \tempo 
                \lilyvartmpe = \lilyvartmpf

error: Error found in this music expression. Ignoring it

Is it a bug or something I'm doing wrong?

/Jonatan    -=( http://kymatica.com )=-