In carpentries/dovetail: Document Engine to Insert Nested Block Quotes

library(dovetail)
library(knitr)
source(dvt_opts())
opts_chunk$set(error = TRUE)

x  <- "The cat purrrs on my lap."

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

#' ## Count words
#' 
#' 1. How many words are in the sentence `x`?
#'
#' @solution
#'
#' There is more than one way of doing this but here is a solution.
#' 
#' ```r
n_words <- length(strsplit(x, " ")[[1]])
n_words
#' ```
#'
#' 1. How many letters are in the sentence `x`?
#' 
#'
#' ```r
n_chars <- nchar(gsub("[^a-zA-Z]", "", x))
n_chars
#' ```

Now that we know that there are r n_words words and r n_chars characters in the sentence. Let's add these 2 numbers

#' ## add these 2 numbers
#' 
#' @challenge
#' Are these variables available?
#' 
#' ```r
#' n_words + n_chars
#' ```

#' - "Define a function using `name <- function(...args...) {...body...}`."
#' - "Call a function using `name(...values...)`."
#' - "R looks for variables in the current stack frame before looking for them at the top level."
#' - "Use `help(thing)` to view help for something."
#' - "Put comments at the beginning of functions to provide help for that function."
#' - "Annotate your code!"
#' - "Specify default values for arguments when defining a function using `name = value` in the argument list."
#' - "Arguments can be passed by matching based on name, by position, or by omitting them (in which case the default value is used)."