On Thu, 7 Feb 2019 00:45:55 +0100 Egmont Koblinger via Unicode <[email protected]> wrote:
> Hi Richard, > > > Not necessarily. One could allow the first strong character in the > > prompt to determine the paragraph directions > > How does Emacs know what's a prompt? How can it tell it from the > previous and next command's output? I don't believe the Emacs terminal does either. What's special about the prompt is that it starts a line, so most paragraphs start with a prompt. Not all prompts contain a strong character. To let a file's contents control directionality, instead of issuing the command 'cat file1' one would have to issue a shell command '(echo; cat file1)' or similar to terminate the paragraph containing the prompt. The 'echo' inserts an empty line. > > That's what the Emacs > > terminal (invoked by M-x term; top level definition in term.el) > > does. > > I tried it. Executed my default shell, and inside that, a "cat > TUTORIAL.he". All the paragraphs are rendered as LTR ones, > left-aligned. Not the way the file is opened in Emacs. See above. I don't know how what your shell is. > If you claim Emacs's built-in terminal emulator supports BiDi, I'm > kindly asking you to present a documentation of its behavior, in > similar spirit to my BiDi proposal. I've a feeling it has emergent behaviour, and may require a lot of experimentation to elucidate. > Does this logic also apply to single newline characters? If not, why > not, what's the conceptual difference? If it does, why do text files > end in a newline? I don't like the convention that removing the newline from the end of a non-empty line changes it into a binary file. The short answer is that some editors allow a text file not to have a final newline; such files are not handled well in the Unix environment. Some things are just untidy messes. Compare C, where a semicolon *terminates* statements, but some are terminated by '}', and a semicolon *separates* the expression within the control part of a for statement, and a comma *separates* the constant definitions in an enum declaration - for a long time, a trailing comma inside the braces was illegal. Richard.
