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| author | Kartik K. Agaram <vc@akkartik.com> | 2021-12-22 18:44:03 -0800 |
|---|---|---|
| committer | Kartik K. Agaram <vc@akkartik.com> | 2021-12-22 18:44:03 -0800 |
| commit | 2c76aa9ff02aaecb99021ed12678cc1aa37c6e2a (patch) | |
| tree | a1bf7daee9ee2bcb476635cdda12359a6cfeb8fb | |
| parent | 77b464fbf0de32868467cb6cb076ec05aabfe5b3 (diff) | |
| download | teliva-2c76aa9ff02aaecb99021ed12678cc1aa37c6e2a.tar.gz | |
toot-toot: more verbose but clearer cursor_down
I actually got all tests to pass on the first try.
| -rw-r--r-- | toot-toot.tlv | 60 |
1 files changed, 44 insertions, 16 deletions
diff --git a/toot-toot.tlv b/toot-toot.tlv index fa841dc..7b59234 100644 --- a/toot-toot.tlv +++ b/toot-toot.tlv @@ -261,28 +261,56 @@ - __teliva_timestamp: original cursor_down: >function cursor_down(s, old_idx) - > local colidx = 0 - > local old_colidx = -1 - > for i=1,string.len(s) do + > local max = string.len(s) + > local i = 1 + > -- compute oldcol, the screen column of old_idx + > local oldcol = 0 + > local col = 0 + > while true do + > if i > max then + > -- abnormal old_idx + > return old_idx + > end > if i == old_idx then - > old_colidx = colidx - > elseif colidx == old_colidx then -- next line - > return i + > oldcol = col + > break > end - > -- loop update > if s[i] == '\n' then - > if old_colidx ~= -1 and old_colidx > colidx then - > return i - > end - > colidx = 0 + > col = 0 > else - > colidx = colidx+1 + > col = col+1 > end + > i = i+1 > end - > if old_colidx == colidx then - > return string.len(s)+1 - > else - > return old_idx + > -- skip rest of line + > while true do + > if i > max then + > -- current line is at bottom + > return old_idx + > end + > if s[i] == '\n' then + > break + > end + > i = i+1 + > end + > -- compute index at same column on next line + > -- i is at a newline + > i = i+1 + > col = 0 + > while true do + > if i > max then + > -- next line is at bottom and is too short; position at end of it + > return i + > end + > if s[i] == '\n' then + > -- next line is too short; position at end of it + > return i + > end + > if col == oldcol then + > return i + > end + > col = col+1 + > i = i+1 > end >end > |