header = c(tr(th("Name", rowspan = 2),
              th("ID", rowspan = 2),
			  th("Membership", colspan = 2),
			  th("Balance", rowspan = 2)),
		   tr(th("Joined"),
		      th("Cancelled")))
```

Revisiting the package notes (July 27, 2025)
============================================
I forgot that `yat` is already useful. It creates a data frame
of summary statistics. If `yat` is for the descriptives
should there be something like `yatlm` or should `yat`
be `yatd` (yet another table of descriptives).

The package can be `yatp` for "yet another table package".

Or should it be `yat1` for `yat another table 1.`?

Formatting
----------
Currently the data frame holding the table content has formatted
values and the underlying values are lost. Is this OK? I am tempted to
try to retain the numerical summary statistics but that is probably
more overhead than I need. I could see how far I can go with the
formatted values. (I could have a function output the raw values
but a value like "3.8 (1.7)" would have two raw values. Is that a list?

If I have `toOrg(yatd(...))` then `toOrg` can sort out whether
I have formatted cells or raw values. This tells me that the
basic use would be to store formatted values in the cells.

Package: yat
Type: Package
Title: Yet Another Way To Create A Summary Table
Version: 0.0.4
Date: 2025-07-29
Authors@R: person(given = "Stephen", family = "Weigand", role = c("aut", "cre"),
                  email = "Weigand.Stephen@mayo.edu")
Maintainer: Stephen Weigand <Weigand.Stephen@mayo.edu>
Description:  Create a table of summary statistics using a formula interface.
  The left hand side of the formula specifies one or more grouping variables
  and the right hand side consists of summary functions (e.g., mean, median, etc.)
  of variables to summarize.

##   </tr>
##   <tr>
##     <th>Joined</th>
##     <th>Canceled</th>
##   </tr>


## yah(~  (`Study {\b A} (n=%d)`  | ... | ... | ... | ... ) / # '.' means empty, '...' means merge with previous
##         ( .   | .  | `Membership dates` | ... | .) /
##         ( Name| ID | Joined | Cancelled | Balance))

## We now have a matrix of content with some cell-contents formatting
## but no alignment information. How does this thing turn into to
## table rows for RTF or HTML?

## How do we get `Group 1 (n=?)` without having to specify 'n'?
## Maybe a literal question mark and that will get filled in? Or
## what about a %d using sprintf formatting?



## This header:
##
## | Characteristic | Group 1 | Group 2 | P-value |
##
## Can be generated with any of these:

## Characteristic ~ `Group 1` + `Group 2` + `P-value`
## ~ Characteristic + `Group 1` + `Group 2` + `P-value`
## Characteristic ~ (`Group 1` | `Group 2` | `P-value`)
## Characteristic ~ `Group 1` | `Group 2` | `P-value`


yah <- function(formula) {
    formula <- check.formula(formula, two.sided = FALSE)
    char <- as.character(formula)
    ## Split on '/' so long as it's not '//' which is how to
    ## escape the slash. So if the header were

    cells <- unlist(cells)
    cells <- sub("^ ?`(.*)` ?", "\\1", cells) # clear back ticks
    cells <- trimws(cells) # clear white space
    matrix(cells, byrow = TRUE, nrow = length(rows))
}


## yah(~ (`A (n=5)` | ... | ...)/(D |.| F)/(G | H | I))


## yah(~ `A (n=5)` | `B (n=165)`)



## Could be a problem if there is a '/' in a cell
## strsplit(as.character(~ `A\\/B` / C / D)[2], "/", fixed = TRUE)

##     (Name      | ID | `Membership Dates` | Balance)

## header <- list(~ h(`Study 1`, 1, 5), 
##                h(Name, 2, 0) ~
##                    h(ID, 2, 0) +
##                    h(`Membership Dates`, 1, 2) +
##                    h(Balance, 2, 0),
##                ~ h(Joined) + h(Cancelled))

## header <- list(~ `Study 1`:1:5)