Am Fr., 21. Okt. 2022 um 20:09 Uhr schrieb Göran Weinholt <xxxxxx@weinholt.se>:

> This code allocates closures and is less efficient than just using
> begin. The sample implementation also has an unreachable syntax-case
> clause.

I was too quick to affirm that the last syntax-case clause is unreachable.

If "perform" is invoked in the identifier form

perform

or in a form like

(perform . bla)

the last clause is actually triggered.  It's not vital, though,
because syntax-case must raise a syntax violation if no clause
matches.  But not any compiler may produce a syntax violation with a
helpful message.

-- Marc