Re: Recent pcase changes

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> By looking at clojure-mode code I see it sets `lisp-indent-function' to
>> `clojure-indent-function', which makes use of `pcase'. More specifically, this
>> is what it does at line 1497 of clojure-mode.el:
>> 
>> (pcase method
>>  ((or (pred integerp) `(,method))

No good deed goes unpunished, eh?

> Now all variables in an `or`-pattern are always bound, to nil if nothing else. Try:
>
>    ((or (pred integerp) `(m))
                          ^^^^^
                          `(,m)

>     (let ((method (if (integerp method) method m)))

With the new semantics you could also use

    (pcase method
      ((or (pred integerp) `(,m))
       (let ((method (or m method)))
       ...

And to get something to work reliably with both the old and the new
semantics, you can go with:

    (pcase method
      ((or (and (pred integerp) method) `(,method))
       ...


-- Stefan