newline rule

[johnny0914]

Shouldn't '\r' be after '\r\n'? Like here

LaTeX.js/src/latex-parser.pegjs

Line 827 in a5b822b

nl "newline" = !'\r''\n' / '\r' / '\r\n' { return undefined; } // catcode 5 (linux, os x, windows)

[michael-brade]

Yes, it should! Thanks for finding this 😁 I guess it's time for another unit test.

[michael-brade]

oh, guess I was too fast (and too smart back then when I wrote it 😜 ). The not ! is the key to make this work. But I agree, it's much more readable without the not, so I'll change it.

[johnny0914]

I have tried the following in PEG.js online and I got r output for rn input.
nl = !'r''n'.* {return "n"} / 'r' .* {return "r"} / 'rn' .* {return "rn" }

The rule will never make it to 'rn' .* {return "rn" }

[michael-brade]

Ok, thinking about it again, you are right. First rule will be ignored if it finds an r, and then the second one will immediately eat the r, so the next time the first will match, never the last one. At least that was the logic I had in mind first this morning.

Now, what I don't really understand yet is that why LaTeX.js, when actually I tried to verify it, didn't interpret \r\n as a paragraph break?! I need to do some debugging...

[michael-brade]

This is really interesting. Even with the new (and correct) code, LaTeX.js/PEG.js never matches the \r\n char sequence. Only \r or \n, and if it is \r, the \n that follows it seems to be eaten by something else. This may be a bug in PEG.js. I don't know yet. So my question to you, since you seem to be using Windows: is it possible for you to use this rule

nl "newline"  = "\n"  { console.log("n") } / "\r\n" { console.log("rn") } / "\r" { console.log("r") }

and run it on a file with Windows EOLs and two or three lines, and then send me the console output?

[johnny0914]

This rule seems to be correct and that's how I have done it.
I have used notepad++ to create the following lines:

and this is the output:
rn n n rn r rn n n r

[michael-brade]

Oh my my.... /me == not so smart after all. The (second) bug is in load-fixtures.ls, which splits the lines to find the tests, and then joins them again with \n. Thank you, I'll have to fix that, too 😄