bug#66057: (ice-9 match) allows invalid usages of ... or ..1

[Jean Abou Samra]

Le dimanche 17 septembre 2023 à 14:17 -0400, Maxim Cournoyer a écrit :

Hi,

After attempting the following:

--8<---------------cut here---------------start------------->8---

(match (string-split "./Bootloaders/Printer/Documentation/html" #\/)

                                 (("." path ..1 "Documentation" "html")

For a start, where does that "..1" syntax come from? To my knowledge, no such syntax is supported by Guile's pattern matcher, which AFAIK is the one described in SRFI-204.

https://srfi.schemers.org/srfi-204/srfi-204.html

So your example is just binding the string "Printer" to the variable "..1": since "..1" doesn't have any special meaning, it's just a pattern variable.

                                  (pk 'path path)))

=> ;;; (path "Bootloaders")

Expected (and works with '...'):

;;; (path "Bootloaders" "Printer")

--8<---------------cut here---------------end--------------->8---

and asking about it in #scheme or #guile, it seems the '..1' and '...'

patterns *must* be used strictly to match at the end of lists,

??

This is not what SRFI 204 says, and it's not consistent with syntax-rules and syntax-case patterns either.

signature.asc
Description: This is a digitally signed message part