Martin Mares <m...@ucw.cz> wrote on 2010/04/29 23:21:48: > > Hello! > > > Haven't you heard a word ? ECHO, REJECT and BEGIN are pre defined > > actions in flex that you can use in your C code. Go read flex again. > > I know that. But what does that really means from the point of view > of C syntax (as used in the C snippets contained in the C source)? > Go read the C standard ;-) > > Does that mean that every occurrence of REJECT as a substring in the > C code is interpreted by flex?
Not likely, but I have never tested that. > > Or does that mean an occurrence of REJECT as an identifier? My money is on this one. > > Or as a C statement? > > Do you see any place in the flex doc which makes this clear? No, but not so strange as flex/lex is way old. > > Historically, all dialects of lex I have ever seen define these constructs > as C macros, so that they do not trigger in strings or in non-expanding > macro parameters and it is possible to un-/redefine them. If flex suddenly > started to scan the source for calls of these actions in a way which does > not really respect C syntax, it is at least a breach of long tradition. > Whether it is a breach of the specs, nobody can tell as the specs are > utterly vague. Well, it must respect C syntax, how else can one use them in the code? Theoretically one could image that REJECT and friends are changed into some inline function but it would be very unpopular I think.
