LIPS command line (read-line (current-input-port)) erases prompt

[dragoncoder047]

(read-line (current-input-port)) is the way I've seen to get a line of input form the user in Scheme. Unfortunately, on LIPS, this doesn't work quite-right, it just erases the prompt. (I'm looking for something equivalent to Python's input() function.)

dc047:/home/dc047> npm list -g | grep lips
├── @jcubic/[email protected]
dc047:/home/dc047> lips --version
(command "lips")
(website "https://lips.js.org")
(languages scheme r5rs r7rs)
(encodings utf-8)
(scheme.srfi 0 1 2 4 6 8 10 22 23 26 46 69 98 111 156 176)
(release "{{VER}}")
(os.uname "linux" "6.2.0-1016-azure")
(os.env.LANG "C.UTF-8")
(os.env.TERM "xterm-256color")
(build.date "{{DATE}}")
dc047:/home/dc047> cat test.scm
(display "Enter a string: ")
; (wait 1000)
(display (concat "You entered: " (read-line (current-input-port))))
dc047:/home/dc047> lips test.scm
hello
You entered: hello                                                                                                                        

It's supposed to wind up with "Enter a string: hello" on the first line after running test.scm. If you uncomment the (wait) call, you can see that the prompt is actually printed, but when it gets to the (read-line), the line is cleared.

If there is a better way of getting input, please let me know.

[jcubic]

Thanks for the report, will try to check it out when I will have time.

[jcubic]

So the problem is because of the way stdin/stdout are created in REPL:

var interp = Interpreter('repl', {
    stdin: InputPort(function() {
        return new Promise(function(resolve) {
            rl = readline.createInterface({
                input: process.stdin,
                output: process.stdout
            });
            rl.question('', function(data) {
                resolve(data);
                rl.close();
            });
        });
    }),
    // -------------------------------------------------------------------------
    stdout: OutputPort(function(x) {
        if (typeof x !== 'string') {
            x = this.get('repr')(x);
        }
        newline = !x.match(/\n$/);
        process.stdout.write(x);
    }),

NodeJS readline.createInterface clears everything that was printed in same line. I think that the quick fix would be to keep text before newline in variable and use it in rl.question instead of empty string.

[jcubic]

the fix seems to work fine. It's available on devel branch.

[dragoncoder047]

how do I npm install -g the devel branch? Do I just point to a specific commit?

[dragoncoder047]

nevermind, I figured it out.

[jcubic]

Best way is to use:

git clone https://github.com/jcubic/lips.git
cd lips
git checkout devel
npm install -g .

There is pending new release beta.17 on devel, I probably should release soon, but if you find some issues let me know, I will be able to fix them before the next release.

[jcubic]

Just released version 1.0.0-beta.17 with a fix.