News for hackers. Stuff that matters.
Re:Regexper – Regular expressions visualizer by dc_gregory on Wednesday January 31, 2018 @12:59AM (#16271806)
This fairly common piece of software does it.

https://www.regexbuddy.com

4th result on google for "regex conversion" for me. Seems like there are quite a few others.

Re:Regexper – Regular expressions visualizer by ken on Friday February 02, 2018 @11:41AM (#16291900)
I'm familiar with that program, but I see no railroad diagrams there.
Re:Regexper – Regular expressions visualizer by ghusbands on Saturday February 03, 2018 @02:25PM (#16299076)
They're replying to the "convert" part, which regexbuddy does [1]

[1] https://www.regexbuddy.com/convert.html