Thank you all for the replies.
Let me just answer the
destructuring-bind comment by Stefan (I am answering to his last email). The previous ones are somewhat answered here as well.
In some sense, yes. I kind of want
destructuring-bind. It is, IMHO, unfortunate that ELisp does not have it and that we don't have
cl-destructuring-bind either; lower level beast than matching, but useful.
As per the pcase-let, I still think that the name and/or its behavior are confusing because of expectations about how a pattern matcher usually works. Of course you have the problems with "no matching" but that semantics can be dealt with separately, without surprising the user (at least me). And note that this is, IMHO, "surprising".
(pcase-let (`(foo bar ,x) '(bar foo 42)) x)
IMHO, this should either return
nil or signal an error. With
destructuring-bind* I would write (assuming indifference variables):
(destructuring-bind* (_ _ x) x)
All the best
Marco