The last line of text printed by the program disappears if it doesn't end with a newline

[tudurom]

Sample program:

use rustyline::{Editor,error::ReadlineError};

fn main() {
    let mut e: Editor<()> = Editor::new();

    loop {
        let rl = e.readline("$ ");
        match rl {
            Ok(_) => {
                print!("text\nwithout\nnewline");
            }
            Err(ReadlineError::Interrupted) | Err(ReadlineError::Eof) => break,
            Err(err) => panic!(err),
        }
    }
}

Expected output:

$ some text here
text
without
newline$ some other

Actual output:

$ some text here
text
without
$ some other

[gwenn]

I will try to see how other libraries behave in this case.

[gwenn]

On unix, linefeed, linenoise, behave the same. liner appends a '⏎'.

[gwenn]

Ok,
We need to retrieve the current cursor position (like this) ! I guess it should be easier on Windows.

[gwenn]

Could you please give PR #224 a try ?

[tudurom]

It is the exact same output, the last word (newline) doesn't appear.

[gwenn]

On Windows ? I need time or your help to find why the PR does not work.
On unix, do you mind checking the logs RUST_LOG=rustyline:debug cargo run --example example 2> debug.log ("initial cursor location: ???"). I made this local change just to test the PR:

-                println!("Line: {}", line);
+                print!("Line: {}\nbim", line);

[tudurom]

Tested on linux, the bim is not shown.

I am not well versed in cargo commands, running that above yields only this in debug.log:

    Finished dev [unoptimized + debuginfo] target(s) in 0.04s
     Running `target/debug/examples/example`

[gwenn]

Sorry, the syntax is 'pkg=level' (not 'pkg:level')...
You should run:

RUST_LOG=rustyline=debug cargo run --example example 2> debug.log

For example:

$ cat debug.log
    Finished dev [unoptimized + debuginfo] target(s) in 0.03s
     Running `target/debug/examples/example`
[2019-05-26T10:14:48Z DEBUG rustyline::tty::unix] initial cursor location: '1'
[2019-05-26T10:14:50Z DEBUG rustyline::tty::unix] key: Char('t')
[2019-05-26T10:14:50Z DEBUG rustyline::keymap] Emacs command: SelfInsert(1, 't')
[2019-05-26T10:14:50Z DEBUG rustyline::undo] Changeset::insert(0, 't')
...

Thanks for your help.

[tudurom]

Here it is:

    Finished dev [unoptimized + debuginfo] target(s) in 0.04s
     Running `target/debug/examples/example`
[2019-05-26T10:24:20Z DEBUG rustyline::tty::unix] initial cursor location: '1'
[2019-05-26T10:24:21Z DEBUG rustyline::tty::unix] key: Char('a')
[2019-05-26T10:24:21Z DEBUG rustyline::keymap] Emacs command: SelfInsert(1, 'a')
[2019-05-26T10:24:21Z DEBUG rustyline::undo] Changeset::insert(0, 'a')
[2019-05-26T10:24:22Z DEBUG rustyline::tty::unix] key: Enter
[2019-05-26T10:24:22Z DEBUG rustyline::keymap] Emacs command: AcceptLine
[2019-05-26T10:24:22Z DEBUG rustyline::tty::unix] initial cursor location: '4'
[2019-05-26T10:24:23Z DEBUG rustyline::tty::unix] key: Char('b')
[2019-05-26T10:24:23Z DEBUG rustyline::keymap] Emacs command: SelfInsert(1, 'b')
[2019-05-26T10:24:23Z DEBUG rustyline::undo] Changeset::insert(0, 'b')
[2019-05-26T10:24:24Z DEBUG rustyline::tty::unix] key: Enter
[2019-05-26T10:24:24Z DEBUG rustyline::keymap] Emacs command: AcceptLine
[2019-05-26T10:24:24Z DEBUG rustyline::tty::unix] initial cursor location: '4'
[2019-05-26T10:24:26Z DEBUG rustyline::tty::unix] key: Ctrl('D')
[2019-05-26T10:24:26Z DEBUG rustyline::keymap] Emacs command: EndOfFile

One observation is that "bim" appears and then quickly disappears, replaced by the prompt.

[gwenn]

You are right!
I just made a fix: 444d53f
Could you please give another try (just update/pull your local branch) ?
Sorry.

[tudurom]

Excellent, it works! Thank you!

[tudurom]

Last minute update: changed the example to this:

print!("Line: {}", line);

Basically, eliminated the "bim" text.

Now, the text gets shown on the screen only if it has at most 2 characters.

[tudurom]

It also shows if the input has at least 13 characters.
So, if the input is between 3 and 12 characters long, it doesn't appear.

Also, if the line doesn't end with a newline (like in the example), it appears on its own line, unlike the expected example I gave in the issue where the text just appears on the left of the prompt.

So, instead of

> line 1
line2>

The result is this (considering that the fix works for inputs between 3 and 12 characters):

> line1
line2
>

[gwenn]

Logs suggest that there is something wrong with initial cursor location.

[gwenn]

Silly me...
I read only the first digit...

[gwenn]

Could you give another try to this ?

[tudurom]

Works!