quartable — Reveal.js demo

colspan · rowspan · midrule · cline · align

Eric Bavu

2026-05-09

Features

quartable extends Markdown pipe tables with six constructs. Each slide below shows the markdown source and the rendered table, so the deck doubles as a feature reference.

Markup	Effect
[text]{cs=N}	merge N consecutive columns
[text]{rs=N} + ^	merge N consecutive rows
===	full-width horizontal separator
===N-M, ===N, ===1,3-5	partial horizontal separator (booktabs \cmidrule)
[text]{cs=N .vl .vr rspan=K}	vertical line(s) on a colspan boundary (LaTeX only)
[text]{align=l\|c\|r}	per-cell alignment override

No automatic head/body separator: write === (or ===N-M) explicitly as the first body row when you want one.

Midrule

Code:

| Group | Value | Note   |
|-------|------:|--------|
| ===   |       |        |
| A     |    12 | first  |
| A     |     8 | second |
| ===   |       |        |
| B     |    15 | third  |

Rendered:

Group	Value	Note
A	12	first
A	8	second
B	15	third

Cline — single range (===N-M)

Code:

| A | B  | C  | D  |
|---|----|----|----|
| === |   |    |    |
| 1 | 2  | 3  | 4  |
| 5 | 6  | 7  | 8  |
| ===2-3 |  |  |    |
| 9 | 10 | 11 | 12 |

Rendered:

A	B	C	D
1	2	3	4
5	6	7	8
9	10	11	12

Cline — mixed ranges (===1,3-4)

A bare N is shorthand for N-N. Mix with ranges using commas.

Code:

| A   | B  | C  | D  |
|-----|----|----|----|
| === |    |    |    |
| 1   | 2  | 3  | 4  |
| ===1,3-4 | | |    |
| 5   | 6  | 7  | 8  |

Rendered:

A	B	C	D
1	2	3	4
5	6	7	8

Colspan in the header

Code:

| Item | [Measurements]{cs=3} |       |       |
|------|:--------------------:|:-----:|------:|
| ===  |                      |       |       |
|      | T1                   | T2    |    T3 |
| ===2-4 |                    |       |       |
| x1   | 0.71                 | 0.68  |  0.74 |
| x2   | 0.69                 | 0.65  |  0.72 |

Rendered:

Item	Measurements
	T1	T2	T3
x1	0.71	0.68	0.74
x2	0.69	0.65	0.72

Colspan in the body

Code:

| Category        | Detail | Value |
|-----------------|:------:|------:|
| ===             |        |       |
| [Group 1]{cs=2} |        |  18.3 |
| ===1-2          |        |       |
| Sub-cat. X      | alpha  |  10.1 |
| Sub-cat. Y      | beta   |   8.2 |

Rendered:

Category	Detail	Value
Group 1		18.3
Sub-cat. X	alpha	10.1
Sub-cat. Y	beta	8.2

Rowspan in the body

Code:

| Condition        | Item | Score |
|------------------|:----:|------:|
| ===              |      |       |
| [Baseline]{rs=3} | x1   |  0.71 |
| ^                | x2   |  0.68 |
| ^                | x3   |  0.74 |
| [Improved]{rs=2} | x1   |  0.89 |
| ^                | x2   |  0.87 |

Rendered:

Condition	Item	Score
Baseline	x1	0.71
	x2	0.68
	x3	0.74
Improved	x1	0.89
	x2	0.87

Rowspan combined with colspan

{rs=N cs=M} on a single cell. Continuation rows use ^.

Code:

| [Block A]{rs=2 cs=2} |       | Value 1 |
|----------------------|-------|---------|
| ^                    | ^     | Value 2 |
| ===                  |       |         |
| Col 1                | Col 2 | Col 3   |

Rendered:

Block A		Value 1
		Value 2
Col 1	Col 2	Col 3

Full table — every feature combined

Code:

| [Method]{rs=2}    | [Set A]{cs=2} |        | [Set B]{cs=2} |       |
|-------------------|:-------------:|:------:|:-------------:|------:|
| ===2-3,4-5        |               |        |               |       |
|                   | Score X       | Score Y| Score X       |Score Y|
| ===               |               |        |               |       |
| Baseline          | 0.71          | 2.1    | 0.68          |   1.9 |
| Wiener            | 0.82          | 2.8    | 0.79          |   2.6 |
| ===               |               |        |               |       |
| **Proposed**      | **0.93**      | **3.7**| **0.92**      |**3.6**|

Rendered:

Method	Set A		Set B
		Score X	Score Y	Score X
Baseline	0.71	2.1	0.68	1.9
Wiener	0.82	2.8	0.79	2.6
Proposed	0.93	3.7	0.92	3.6

Per-cell alignment override (regular cells)

align= overrides the column’s Markdown alignment. Both short (l/c/r) and long (left/center/right) values work.

Code:

| Description    |                       Value |
|:---------------|----------------------------:|
| Default        |                          42 |
| Default        |             a longer phrase |
| `align=l`      | [42]{align=l}               |
| `align=c`      | [two words]{align=c}  |

Rendered:

Description	Value
Default	42
Default	a longer phrase
align=l	42
align=c	two words

Per-cell alignment override (colspan cells)

The cs > 1 default is centered. align= overrides it.

Code:

| Step | A   | B   | Total |
|:-----|:---:|:---:|------:|
| ===  |     |     |       |
| 1    | [data]{cs=3}              |   |   |
| 2    | [data]{cs=3 align=l}      |   |   |
| 3    | [data]{cs=3 align=r}      |   |   |
| ===2-4 |   |     |       |
| 4    | 12  | 34  |   100 |

Rendered:

Step	A	B	Total
1	data
2	data
3	data
4	12	34	100

Vlines — LaTeX only

.vl and .vr draw vertical lines on a cell’s left/right edge (or on the boundary of a colspan). rspan=K limits the line to K rows.

⚠ Vlines are LaTeX only in v0.1. They do not render in HTML or Reveal — see the corresponding section in the PDF test for the visual.

Code:

| Item | [Measurements]{cs=2 .vr} |   | Note |
|------|:------------------------:|:-:|------|
| ===  |                          |   |      |
| A    | 1                        | 2 | foo  |
| B    | 3                        | 4 | bar  |

Rendered:

Item	Measurements		Note
A	1	2	foo
B	3	4	bar

Edge case — rowspan crossing a midrule

The filter prints a stderr warning and renders the table as best as HTML/Reveal allow. (LaTeX rendering of this specific case is imperfect because \multirow cannot cross \midrule cleanly.)

Code:

| Group            | Value |
|------------------|------:|
| ===              |       |
| [CONFLICT]{rs=3} |     1 |
| ^                |     2 |
| ===              |       |
| ^                |     3 |

Rendered:

Group	Value
CONFLICT	1
	2
3