JShell: Request for ideas: Editing multiline snippets, adding lines

[Jan Lahoda]

On 6.12.2018 06:08, Michel Trudeau wrote:
> What about Ctrl-Enter ?

Actually, Alt-Enter turnes out to work on Linux (KDE Konsole) as a 
shortcut to add a new line. The main issue here is that we can only use 
shortcuts for which the terminal will produce an escape sequence, and 
IIRC on Mac this was very troublesome (the shortcuts that produced 
escape sequences and that we could use were severely limited). So the 
Alt-Enter may not work on Mac (I believe we wanted to have the "add 
import" bound to Alt-Enter and it was not possible on Mac). If someone 
with Mac could try with this patch:
---
diff -r 183e274baccd 
src/jdk.internal.le/share/classes/jdk/internal/org/jline/keymap/BindingReader.java
--- 
a/src/jdk.internal.le/share/classes/jdk/internal/org/jline/keymap/BindingReader.java 
        Thu Dec 06 15:05:31 2018 +0100
+++ 
b/src/jdk.internal.le/share/classes/jdk/internal/org/jline/keymap/BindingReader.java 
        Thu Dec 06 16:00:04 2018 +0100
@@ -11,7 +11,10 @@
  import java.io.IOError;
  import java.io.IOException;
  import java.util.ArrayDeque;
+import java.util.Arrays;
  import java.util.Deque;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;

  import jdk.internal.org.jline.reader.EndOfFileException;
  import jdk.internal.org.jline.utils.ClosedException;
@@ -112,6 +115,12 @@
                  return null;
              }
              opBuffer.appendCodePoint(c);
+            System.err.print("opBuffer='");
+            for (char cc : opBuffer.toString().toCharArray()) {
+                System.err.print(Integer.toHexString(cc));
+                System.err.print(" ");
+            }
+            System.err.println("'");
              hasRead = true;
          }
          return null;
---

When a key or a combination of keys is pressed, it should print output like:
opBuffer='1b d '
(this is for Alt-Enter for me). If there's some useful combination on 
Mac that prints something distinguishable, we can use that as a shortcut.

Thanks,
     Jan

>
> On Dec 5, 2018, at 8:46 PM, Robert Field <robert.field at oracle.com> wrote:
>
> A fix about to go back to JDK 12 (see JLine 3 review discussion) provides a significant improvement when editing multiline snippets — they are treated as an integral unit — with WYSIWYG-ish interaction.
>
> There is however one limitation:  Since <return> has its legacy action of accepting the input, there is no way with line editing to add a line within a multiline snippet.
>
> It would seem that a different input is needed to add a line (unless I’m missing something).  Suggestions for that keystroke are herein solicited.
>
> Thanks,
> Robert
>
>