Hi, tl;dr How should I use named Unicode character classes in regexps?
I'm trying to write a regular expression that matches Go identifiers <https://golang.org/ref/spec#Identifiers>, which start with a Unicode letter or underscore followed by zero or more Unicode letters, decimal digits, and/or underscores. Based on the regexp syntax <https://godoc.org/regexp/syntax>, and the variables in the unicode package <https://golang.org/pkg/unicode/#pkg-variables> which mention the classes "Letter" and "Number, decimal digit", I was expecting to write something like: identiferRegexp := regexp.MustCompile(`\A[[\p{Letter}]_][[\p{Letter}][\p{Number, decimal digit}]_]*\z`) However, this pattern does not compile, giving the error: regexp: Compile(`\A[[\p{Letter}]_][[\p{Letter}][\p{Number, decimal digit}]_]*\z`): error parsing regexp: invalid character class range: `\p{Letter}` Using the short name for character classes (L for Letter, Nd for Number, decimal digit) does work however: identiferRegexp := regexp.MustCompile(`\A[\pL_][\pL\p{Nd}_]*\z`) You can play with these regexps on play.golang.org <https://play.golang.org/p/WITTbqvom9F>. Is this simply an oversight that Unicode character classes like "Letter" and "Number, decimal digit" are not available for use in regexps, or should I be using them differently? Many thanks, Tom -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/844b99d5-0ae1-4e29-b576-cd4f1b1c24b3%40googlegroups.com.
