How to use Regex() function?

General Usage
1

r"(?<=NH3\)\[)\w+(?=\])" is ok but Regex("(?<=NH3\)\[)\w+(?=\])") reports

ERROR: LoadError: syntax: invalid escape sequence

why?

3

OK. just figured out… Need to use \\ instead of \ . The documentation should have mentioned that …

4

The string macro form doesn’t recognize \ as an escape character, it’s just another character in the regex (which has its own escape functionality according to regex). But in normal Julia strings, if you use \ it needs to be part of an escape sequence such as \n (newline) or \\ (literal backslash). If you want to use the Regex constructor, you can use Regex(raw"my_string \ with weird escapes").

2 Likes
6

https://docs.julialang.org/en/v1/manual/metaprogramming/#man-macros

it does by showing you you need \\ if you’re constructing via Regex()

7

Cool. Maybe it should also be in ?help …

8

This is not what ?help does (try it out).