Cl-ppcre: regex-replace and backslash instead
Perhaps these questions really got stuck, but I'm stuck. How can I put a backslash in the replacement cl-ppcre:regex-replace-all
?
For example, I just want to escape some characters like "" (), etc., so I will tackle substitution | replacement to make sure the match is ok:
CL-USER> (princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)" "|\\1"))
PRINTED: foo |"bar|" |'baz|' |(test|)
Ok, let's slash:
CL-USER> (princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)" "\\\1"))
PRINTED: foo "bar" 'baz' (test) ;; No luck
No, we have replaced two slashes:
CL-USER> (princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)" "\\\\1"))
PRINTED: foo \1bar\1 \1baz\1 \1test\1 ;; Got slash, but not \1
Maybe so?
(princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)" "\\\{1}"))
PRINTED: foo "bar" 'baz' (test) ;; Nope, no luck here
Of course, if I put a space between the forward slash, that's ok, but I don't need it
(princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)" "\\ \\1"))
PRINTED: foo \ "bar\ " \ 'baz\ ' \ (test\ )
So how can I write to print foo \"bar\" \'baz\' \(test\)
? Thank you.
source to share
Six original forward slashes
CL-USER> (princ (cl-ppcre:regex-replace-all "(['\\(\\)\"])"
"foo \"bar\" 'baz' (test)"
"\\\\\\1"))
foo \"bar\" \'baz\' \(test\)
When you write a string in your source code, each forward slash is used as an escape. You want the replacement text to be a sequence of characters \\1
. To encode the first forward slash in a replacement (since CL-PPCRE will handle forward slashes), CL-PPCRE must see a sequence of characters \\\1
. The first two slashes encode the forward slash and the third encodes the group number. To get this sequence of characters as a Lisp string, you must write "\\\\\\1"
.
source to share