A text editor

Now we want to turn our text viewer in a proper editor. I guess it's the natural progression for this kind of things. Not to mention that our guide is called "Build a text editor", not "Build a text viewer". Let's not forget that.

Let's start by handling more keypresses in the processKeypress() function.

We add new switch prongs for Backspace, Del and Enter:

        .backspace, .ctrl_h, .del => {
            if (k == .del) {
                e.moveCursorWithKey(.right);
            }
            try e.deleteChar();
            e.doCwant(.set);
        },

        .enter => try e.insertNewLine(),

We also change our else branch to handle characters to be inserted. We only handle Tab and printable characters, for now.

        else => {
            const c = @intFromEnum(k);
            if (k == .tab or asc.isPrint(c)) {
                try e.insertChar(c);
                e.doCwant(.set);
            }
        },

There is a new constant to set:

const asc = std.ascii;

And new functions to implement:

• insertChar will insert a character at cursor positin
• deleteChar will delete the character on the left of the cursor
• insertNewLine will start editing a new line after the current one