It might reduce wear and tear on disk, and losing 3 seconds of data
doesn't feel catastrophic (short of a C-z rampage).
Thanks to the love2d.org community for the suggestion:
https://love2d.org/forums/viewtopic.php?f=14&t=93173
Not sure where that idiom comes from or why strings work in some places
(auto-coercion?). I picked it up off some example apps. But
https://love2d.org/wiki/love.mouse.isDown says it should be an integer.
manifestation: clicking past end of a long, wrapping line containing
non-ASCII would cause the cursor to disappear rather than position past
end of screen line. Hitting enter would then throw an assertion with the
following stack trace:
Error: text.lua:381: bad argument #2 to 'sub' (number expected, got nil)
stack traceback:
[love "boot.lua"]:345: in function <[love "boot.lua"]:341>
[C]: in function 'sub'
text.lua:381: in function 'insert_return'
text.lua:179: in function 'keychord_pressed'
main.lua:495: in function 'keychord_pressed'
keychord.lua:10: in function <keychord.lua:5>
app.lua:34: in function <app.lua:25>
[C]: in function 'xpcall'
cause: the click caused a call to Text.to_pos_on_line whose result was
not on a UTF-8 character boundary.
fix: make to_pos_on_line utf8-aware.
Any time I press a ctrl- chord LÖVE actually sees two key chords:
C-lctrl
C-... (the real one)
But it's not just that. There's also a lot in the codebase that's just
habit-based. I need more tests.
All signs so far seem to be that CPU is cheap for this application, but
memory is expensive. It's easy to get sluggish if the GC comes on.
After some experiments using https://github.com/yaukeywang/LuaMemorySnapshotDump,
one source of memory leaks is rendered fragments (https://love2d.org/wiki/Text
objects). I need to render text in approximately word-sized fragments to
mostly break lines more intelligently at word boundaries.
I've attached the files I used for my experiments (suffixed with a '.')
There's definitely still a leak in fragments. The longer I edit, the
more memory goes to them.
I've tried to keep the time period of the blinking similar to my
terminal.
Honestly I'm no longer sure if any of my experiments are showing a
statistically significant result. Let's see how it feels over a period
of time.
This still isn't ideal. On my Linux laptop for some reason the window
receives a signal to maximize itself soon after (but sometime after) the
program starts.
I'm being unprincipled at the moment between pos and x,y coordinates.
Whatever is more convenient. Perhaps a cleaner approach will come to me
over time.
It's still a bit simple-minded. Most software will keep the first bound
fixed and move the second. Lines currently has the bounds in a queue of
sorts. But I have a test to indicate the behavior that is definitely
desired. We'll see if we need it to get more complex.
Mouse stuff is pretty strenuous. For the first time I have to be careful
not to recompute too often. And I ran into a race condition for the
first time where resetting line.y within App.draw meant mouse clicks
were extremely unlikely to see line.y set.
Incredibly inefficient, but I don't yet know how to efficiently encode
undo mutations that can span multiple lines.
There seems to be one bug related to creating new drawings; they're not
spawning events and undoing past drawing creation has some weird
artifacts. Redo seems to consistently work, though.
I've written a few tests for delete_selection, but the way different
operations initialize the selection seems fairly standard and not worth
testing so far.
I'm now extracting the concern of computing
line.screen_line_starting_pos out of Text.draw. Earlier
I had to make sure I ran through the whole line to compute
screen_line_starting_pos, but that had the side-effect of updating
Screen_bottom1.pos as well with lines that had never been rendered.
In this process I hit my first bug due to an accidental global. It
doesn't show up in the patch because I accidentally deleted a local
declaration. (I thought I didn't need screen_line_starting_pos anymore,
deleted everywhere, then brought it back everywhere from the bottom of
the function up, but forgot to put back the very first occurrence.)
The amount of yoyoing this caused between App.draw and Text.draw, I very
much have spaghetti on my hands.
Accidental globals are _terrible_ in a program with tests. Cross test
contamination X-(
I also really need to rethink how people debug my programs. My approach
of inserting and deleting print() takes a lot of commitment. I need my
old trace-based whitebox testing idea. However, in my past projects I
never did figure out a good framework for tweaking how verbose a trace
to emit.
Perhaps that's too many knobs. Perhaps we just need a way to run a
single test with the most verbose trace possible. Then it's just a
matter of having the trace tell a coherent story? But even if the trace
stays out of program output in that situation, it's still in the
programmer's face in the _code_. Ugh.
Current plan: ship program with maximum tests and zero commented-out
prints. If you want to debug, insert prints. This is better than
previous, text-mode, projects just by virtue of the stdout channel being
dedicated to debug stuff.
I have no fucking idea what I'm doing. All I know is that there's still
too many goddamn bugs[1]. Test motherfucking harness or bust. For
starters this is just the default love.run from
https://love2d.org/wiki/love.run
[1] The following file crashes if you repeatedly press cursor-down:
<<
a
b
c
```lines
```
x
>>
So far I've just changed how existing variables are organized, and put
some scaffolding in place for dealing with the new types. Next up:
rewriting the code for scrolling to something that feels more obviously
correct.
Manual test used here:
abc
```lines
{"p1":{"y":72,"x":82},"mode":"line","p2":{"y":29,"x":169}}
```
def
```lines
{"p1":{"y":36,"x":56},"mode":"line","p2":{"y":59,"x":163}}
```
```lines
```
ghi
jkl
Hitting page-down moves the cursor from abc to ghi. The 'ghi' line
should be fully visible on screen.
Still some limitations. The text cursor has to be visible on screen, so
if you have a long series of drawings without intervening lines of text
you won't be able to scroll through them all.