example.qmd

---
title: "Code-fullscreen Example"
author: Shafayet Khan Shafee
date: last-modified
data-format: "DD MMM, YYYY"
filters:
  - code-fullscreen
execute: 
  echo: true
code-line-numbers: true
format: 
  html:
    code-tools: true
embed-resources: true
---

> View the source code of this document by clicking `</> Code` on the top-right corner.

For HTML format this extension may seem useful where you have a very long code with many lines and you have made the code block scrollable using css.

## Very Long R code

::: {.scrollable}

```{r}
#| eval: false
# source code of stats::lm
function (formula, data, subset, weights, na.action, method = "qr", 
    model = TRUE, x = FALSE, y = FALSE, qr = TRUE, singular.ok = TRUE, 
    contrasts = NULL, offset, ...) 
{
    ret.x <- x
    ret.y <- y
    cl <- match.call()
    mf <- match.call(expand.dots = FALSE)
    m <- match(c("formula", "data", "subset", "weights", "na.action", 
        "offset"), names(mf), 0L)
    mf <- mf[c(1L, m)]
    mf$drop.unused.levels <- TRUE
    mf[[1L]] <- quote(stats::model.frame)
    mf <- eval(mf, parent.frame())
    if (method == "model.frame") 
        return(mf)
    else if (method != "qr") 
        warning(gettextf("method = '%s' is not supported. Using 'qr'", 
            method), domain = NA)
    mt <- attr(mf, "terms")
    y <- model.response(mf, "numeric")
    w <- as.vector(model.weights(mf))
    if (!is.null(w) && !is.numeric(w)) 
        stop("'weights' must be a numeric vector")
    offset <- model.offset(mf)
    mlm <- is.matrix(y)
    ny <- if (mlm) 
        nrow(y)
    else length(y)
    if (!is.null(offset)) {
        if (!mlm) 
            offset <- as.vector(offset)
        if (NROW(offset) != ny) 
            stop(gettextf("number of offsets is %d, should equal %d (number of observations)", 
                NROW(offset), ny), domain = NA)
    }
    if (is.empty.model(mt)) {
        x <- NULL
        z <- list(coefficients = if (mlm) matrix(NA_real_, 0, 
            ncol(y)) else numeric(), residuals = y, fitted.values = 0 * 
            y, weights = w, rank = 0L, df.residual = if (!is.null(w)) sum(w != 
            0) else ny)
        if (!is.null(offset)) {
            z$fitted.values <- offset
            z$residuals <- y - offset
        }
    }
    else {
        x <- model.matrix(mt, mf, contrasts)
        z <- if (is.null(w)) 
            lm.fit(x, y, offset = offset, singular.ok = singular.ok, 
                ...)
        else lm.wfit(x, y, w, offset = offset, singular.ok = singular.ok, 
            ...)
    }
    class(z) <- c(if (mlm) "mlm", "lm")
    z$na.action <- attr(mf, "na.action")
    z$offset <- offset
    z$contrasts <- attr(x, "contrasts")
    z$xlevels <- .getXlevels(mt, mf)
    z$call <- cl
    z$terms <- mt
    if (model) 
        z$model <- mf
    if (ret.x) 
        z$x <- x
    if (ret.y) 
        z$y <- y
    if (!qr) 
        z$qr <- NULL
    z
}

```


```{css, echo=FALSE}
.scrollable {
  max-height: 500px;
  overflow-y: scroll;
}
```

:::

## Lua code

```{.lua}
-- code snippet taken from 
-- https://pandoc.org/lua-filters.html#counting-words-in-a-document
-- for demo.
-- counts words in a document

words = 0

wordcount = {
  Str = function(el)
    -- we don't count a word if it's entirely punctuation:
    if el.text:match("%P") then
        words = words + 1
    end
  end,

  Code = function(el)
    _,n = el.text:gsub("%S+","")
    words = words + n
  end,

  CodeBlock = function(el)
    _,n = el.text:gsub("%S+","")
    words = words + n
  end
}

function Pandoc(el)
    -- skip metadata, just count body:
    el.blocks:walk(wordcount)
    print(words .. " words in body")
    os.exit(0)
end
```