ascii-art-fix

ASCII Art Fix

Fix misaligned right borders in ASCII art box diagrams. Prompt-driven — no external tools required.

Recognizing ASCII Box Diagrams

Box diagrams use border characters to draw rectangular outlines:

Plus-dash style:

+-------------------+
| Content here      |
+-------------------+

Unicode style:

┌─────────────────┐
│ Content here    │
└─────────────────┘

How to Fix

1. Find each box — identify top/bottom borders (lines of +---+ or ┌───┐ / └───┘)
2. Measure the box width — count characters in the top border from first + to last + (inclusive)
3. Pad each content line — every | or │ content line between borders must have its closing border character at the same column as the border width
4. Preserve everything else — do not modify any text outside box diagrams

Rules

DO fix:

• Content lines where the closing | or │ is at the wrong column
• Pad with spaces between content and closing border
• Borders with the wrong corner glyphs — a top border uses ┌…┐, a bottom border uses └…┘ (a bottom drawn as ┌…┐ gets its corners replaced)

DO NOT touch:

• Markdown tables (| Col | Col | with |---|---| separator rows)
• Content inside fenced code blocks (``` or ~~~)
• Flow arrows or connectors between boxes (|, v, ---->)
• Lines that don't belong to a box diagram
• Already-aligned boxes

Distinguishing Tables from Boxes

Markdown tables have:

• Multiple | characters per line separating columns
• A separator row matching |---|---| (dashes with optional colons)
• No + corner characters

Box diagrams have:

• + or ┌└┐┘ corner characters on border lines
• Exactly two | or │ per content line (opening and closing)
• Horizontal borders made of - or ─

If a line has a |---| separator row, it's a table. Leave it alone.

Verify Your Work

After fixing, check that every line in each box is the same width. Nested boxes are especially tricky — the outer box content lines that contain an inner box still need their closing | at the outer box's column:

+------------------+          <- width 20, | at column 20
| Outer content    |          <- | at column 20 ✓
|  +----------+    |         <- | at column 20 ✓ (not column 17)
|  | Inner    |    |         <- | at column 20 ✓
|  +----------+    |         <- | at column 20 ✓
+------------------+

Run the validator to catch misalignment:

python3 scripts/validate.py <file>

Eval

Run the eval to check your work:

bash skills/ascii-art-fix/scripts/clean.sh
# process each case in assets/cases/*/
bash skills/ascii-art-fix/scripts/eval.sh

See references/evaluating.md for the full eval workflow.