Surprisingly the regex matcher does not match backslash correcly. For example
Regex.split(~r{\\}, "C:\foo\bar")
["C:\foo\bar"]
Regex.match?(~r/\\/, "C:\foo\bar")
false
I would expect a positive match, but maybe I'm escaping \ wrong. Let's test that out:
Regex.escape("\\")
"\\\\"
Regex.split(~r{\\\\}, "C:\foo\bar")
["C:\foo\bar"]
Regex.match?(~r/\\\\/, "C:\foo\bar")
false
Still no match. Fairly confused at this point. How do you escape \ in a regex to match a literal \ as you can see in my usecase I would like to split a windows path.
Regex is fine; your input is not what you think it is. Backslash inside strings escapes.
String.split("C:\foo\bar", "")
#⇒ ["", "C", ":", "\f", "o", "o", "\b", "a", "r", ""]
String.length("C:\foo\bar")
#⇒ 8
Note "\f" and "\b" there. The string contains no backslash, but it contains "\f" and "\b" codepoints.
That said, you need to pass a proper string to Regex.split/3 to yield the expected result.
Regex.split(~r|\\|, "C:\\foo\\bar")
#⇒ ["C:", "foo", "bar"]