Question

I’m using ragel with C as the host language.

I can recognise a newline simply with ‘\n’, but I need to recognise the start of the file as an alternative.

In other implementations of regex this could be given by \A or $, but $ is reserved for other purposes, '\A' maps to something else (alarm?) and \A gives a parser error.

Answer 1

I don’t think there’s an escape sequence for that. However, you can detect it by checking if Ragel’s ts variable equals 0.