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This is a wrapper for several Episode class objects.

Details

Lessons are made of up several episodes within the _episodes/ directory of a lesson. This class keeps track of several episodes and allows us to switch between RMarkdown and markdown episodes

Public fields

path

[character] path to Lesson directory

episodes

[list] list of Episode class objects representing the episodes of the lesson.

built

[list] list of Episode class objects representing the markdown artefacts rendered from RMarkdown files.

extra

[list] list of Episode class objects representing the extra markdown components including index, setup, information for learners, information for instructors, and learner profiles. This is not processed for the jekyll lessons.

sandpaper

[logical] when TRUE, the episodes in the lesson are written in pandoc flavoured markdown. FALSE would indicate a jekyll-based lesson written in kramdown.

rmd

[logical] when TRUE, the episodes represent RMarkdown files, default is FALSE for markdown files (deprecated and unused).

Active bindings

n_problems

number of problems per episode

show_problems

contents of the problems per episode

files

the source files for each episode

Methods


Method new()

create a new Lesson object from a directory

Usage

Lesson$new(path = ".", rmd = FALSE, jekyll = TRUE, ...)

Arguments

path

[character] path to a lesson directory. This must have a folder called _episodes within that contains markdown episodes. Defaults to the current working directory.

rmd

[logical] when TRUE, the imported files will be the source RMarkdown files. Defaults to FALSE, which reads the rendered markdown files.

jekyll

[logical] when TRUE (default), the structure of the lesson is assumed to be derived from the carpentries/styles repository. When FALSE, The structure is assumed to be a sandpaper lesson and extra content for learners, instructors, and profiles will be populated.

...

arguments passed on to Episode$new

Returns

a new Lesson object that contains a list of Episode objects in $episodes

Examples

frg <- Lesson$new(lesson_fragment())
frg$path
frg$episodes


Method load_built()

read in the markdown content generated from RMarkdown sources and load load them into memory

Usage

Lesson$load_built()


Method get()

A getter for various active bindings in the Episode class of objects. In practice this is syntactic sugar around purrr::map(l$episodes, ~.x$element)

Usage

Lesson$get(element = NULL, collection = "episodes")

Arguments

element

[character] a defined element from the active bindings in the Episode class. Defaults to NULL, which will return nothing. Elements that do not exist in the Episode class will return NULL

collection

[character] one or more of "episodes" (default), "extra", or "built". Select TRUE to collect information from all files.

Examples

frg <- Lesson$new(lesson_fragment())
frg$get("error") # error code blocks
frg$get("links") # links


Method summary()

summary of element counts in each episode. This can be useful for assessing a broad overview of the lesson dynamics

Usage

Lesson$summary(collection = "episodes")

Arguments

collection

[character] one or more of "episodes" (default), "extra", or "built". Select TRUE to collect information from all files.

Examples

frg <- Lesson$new(lesson_fragment())
frg$summary() # episode summary (default)


Method blocks()

Gather all of the blocks from the lesson in a list of xml_nodeset objects

Usage

Lesson$blocks(type = NULL, level = 0, path = FALSE)

Arguments

type

the type of block quote in the Jekyll syntax like ".challenge", ".discussion", or ".solution"

level

the level of the block within the document. Defaults to 0, which represents all of the block_quotes within the document regardless of nesting level.

path

[logical] if TRUE, the names of each element will be equivalent to the path. The default is FALSE, which gives the name of each episode.

body

the XML body of a carpentries lesson (an xml2 object)


Method challenges()

Gather all of the challenges from the lesson in a list of xml_nodeset objects

Usage

Lesson$challenges(path = FALSE, graph = FALSE, recurse = TRUE)

Arguments

path

[logical] if TRUE, the names of each element will be equivalent to the path. The default is FALSE, which gives the name of each episode.

graph

[logical] if TRUE, the output will be a data frame representing the directed graph of elements within the challenges. See the get_challenge_graph() method in Episode.

recurse

[logical] when graph = TRUE, this will include the solutions in the output. See Episode for more details.


Method solutions()

Gather all of the solutions from the lesson in a list of xml_nodeset objects

Usage

Lesson$solutions(path = FALSE)

Arguments

path

[logical] if TRUE, the names of each element will be equivalent to the path. The default is FALSE, which gives the name of each episode.


Method thin()

Remove episodes that have no challenges

Usage

Lesson$thin(verbose = TRUE)

Arguments

verbose

[logical] if TRUE (default), the names of each episode removed is reported. Set to FALSE to remove this behavior.

Returns

the Lesson object, invisibly

Examples

frg <- Lesson$new(lesson_fragment())
frg$thin()


Method reset()

Re-read all Episodes from disk

Usage

Lesson$reset()

Returns

the Lesson object

Examples

frg <- Lesson$new(lesson_fragment())
frg$episodes[[1]]$body
frg$isolate_blocks()$episodes[[1]]$body # empty
frg$reset()$episodes[[1]]$body # reset


Method isolate_blocks()

Remove all elements except for those within block quotes that have a kramdown tag. Note that this is a destructive process.

Usage

Lesson$isolate_blocks()

Returns

the Episode object, invisibly

Examples

frg <- Lesson$new(lesson_fragment())
frg$isolate_blocks()$body # only one challenge block_quote


Method handout()

create a handout for all episodes in the lesson

Usage

Lesson$handout(path = NULL, solution = FALSE)

Arguments

path

the path to the R Markdown file to be written. If NULL (default), no file will be written and the lines of the output document will be returned.

solution

if TRUE solutions will be retained. Defaults to FALSE

Returns

if path = NULL, a character vector, otherwise, the object itself is returned.

Examples

lsn <- Lesson$new(lesson_fragment("sandpaper-fragment"), jekyll = FALSE)
cat(lsn$handout())
cat(lsn$handout(solution = TRUE))


Method validate_headings()

Validate that the heading elements meet minimum accessibility requirements. See the internal validate_headings() for deails.

This will validate the following aspects of all headings:

  • first heading starts at level 2 (first_heading_is_second_level)

  • greater than level 1 (greater_than_first_level)

  • increse sequentially (e.g. no jumps from 2 to 4) (are_sequential)

  • have names (have_names)

  • unique in their own hierarchy (are_unique)

Usage

Lesson$validate_headings(verbose = TRUE)

Arguments

verbose

if TRUE, the heading tree will be printed to the console with any warnings assocated with the validators

Returns

a data frame with a variable number of rows and the follwoing columns:

  • episode the filename of the episode

  • heading the text from a heading

  • level the heading level

  • pos the position of the heading in the document

  • node the XML node that represents the heading

  • (the next five columns are the tests listed above)

  • path the path to the file.

Each row in the data frame represents an individual heading across the Lesson. See validate_headings() for more details.

Examples

frg <- Lesson$new(lesson_fragment())
frg$validate_headings()


Method validate_divs()

Validate that the divs are known. See the internal validate_divs() for details.

Validation variables

  • divs are known (is_known)

Usage

Lesson$validate_divs()

Arguments

verbose

if TRUE (default), Any failed tests will be printed to the console as a message giving information of where in the document the failing divs appear.

Returns

a wide data frame with five rows and the number of columns equal to the number of episodes in the lesson with an extra column indicating the type of validation. See the same method in the Episode class for details.

Examples

frg <- Lesson$new(lesson_fragment())
frg$validate_divs()


Validate that the links and images are valid and accessible. See the internal validate_links() for details.

Validation variables

  • External links use HTTPS (enforce_https)

  • Internal links exist (internal_okay)

  • External links are reachable (all_reachable) (planned)

  • Images have alt text (img_alt_text)

  • Link text is descriptive (descriptive)

  • Link text is more than a single letter (link_length)

Usage

Lesson$validate_links()

Arguments

verbose

if TRUE (default), Any failed tests will be printed to the console as a message giving information of where in the document the failing links/images appear.

Returns

a wide data frame with five rows and the number of columns equal to the number of episodes in the lesson with an extra column indicating the type of validation. See the same method in the Episode class for details.

Examples

frg <- Lesson$new(lesson_fragment())
frg$validate_links()


Method clone()

The objects of this class are cloneable with this method.

Usage

Lesson$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples


## ------------------------------------------------
## Method `Lesson$new`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$path
#> [1] "/home/runner/work/_temp/Library/pegboard/lesson-fragment"
frg$episodes
#> $`10-lunch.md`
#> <Episode>
#>   Inherits from: <yarn>
#>   Public:
#>     add_md: function (md, where = 0L) 
#>     body: xml_document, xml_node
#>     challenges: active binding
#>     clone: function (deep = FALSE) 
#>     code: active binding
#>     confirm_sandpaper: function () 
#>     error: active binding
#>     get_blocks: function (type = NULL, level = 1L) 
#>     get_challenge_graph: function (recurse = TRUE) 
#>     get_divs: function (type = NULL, include = FALSE) 
#>     get_images: function (process = FALSE) 
#>     get_yaml: function () 
#>     handout: function (path = NULL, solutions = FALSE) 
#>     head: function (n = 6L) 
#>     headings: active binding
#>     images: active binding
#>     initialize: function (path = NULL, process_tags = TRUE, fix_links = TRUE, 
#>     isolate_blocks: function () 
#>     keypoints: active binding
#>     label_divs: function () 
#>     lesson: active binding
#>     links: active binding
#>     move_keypoints: function () 
#>     move_objectives: function () 
#>     move_questions: function () 
#>     name: active binding
#>     ns: http://commonmark.org/xml/1.0
#>     objectives: active binding
#>     output: active binding
#>     path: /home/runner/work/_temp/Library/pegboard/lesson-fragment ...
#>     protect_curly: function () 
#>     protect_math: function () 
#>     protect_unescaped: function () 
#>     questions: active binding
#>     remove_error: function () 
#>     remove_output: function () 
#>     reset: function () 
#>     show: function () 
#>     show_problems: active binding
#>     solutions: active binding
#>     summary: function () 
#>     tags: active binding
#>     tail: function (n = 6L) 
#>     unblock: function (token = "#'") 
#>     use_dovetail: function () 
#>     use_sandpaper: function (rmd = FALSE, yml = list()) 
#>     validate_divs: function (warn = TRUE) 
#>     validate_headings: function (verbose = TRUE, warn = TRUE) 
#>     validate_links: function (warn = TRUE) 
#>     warning: active binding
#>     write: function (path = NULL, format = "md", edit = FALSE) 
#>     yaml: --- layout: break title: "Lunch" teaching: 0 exercises:  ...
#>   Private:
#>     clear_yaml_item: function (what) 
#>     deep_clone: function (name, value) 
#>     encoding: UTF-8
#>     md_lines: function (path = NULL, stylesheet = NULL) 
#>     mutations: FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#>     problems: list
#>     record_problem: function (x) 
#>     sourcepos: TRUE
#> 
#> $`12-for-loops.md`
#> <Episode>
#>   Inherits from: <yarn>
#>   Public:
#>     add_md: function (md, where = 0L) 
#>     body: xml_document, xml_node
#>     challenges: active binding
#>     clone: function (deep = FALSE) 
#>     code: active binding
#>     confirm_sandpaper: function () 
#>     error: active binding
#>     get_blocks: function (type = NULL, level = 1L) 
#>     get_challenge_graph: function (recurse = TRUE) 
#>     get_divs: function (type = NULL, include = FALSE) 
#>     get_images: function (process = FALSE) 
#>     get_yaml: function () 
#>     handout: function (path = NULL, solutions = FALSE) 
#>     head: function (n = 6L) 
#>     headings: active binding
#>     images: active binding
#>     initialize: function (path = NULL, process_tags = TRUE, fix_links = TRUE, 
#>     isolate_blocks: function () 
#>     keypoints: active binding
#>     label_divs: function () 
#>     lesson: active binding
#>     links: active binding
#>     move_keypoints: function () 
#>     move_objectives: function () 
#>     move_questions: function () 
#>     name: active binding
#>     ns: http://commonmark.org/xml/1.0
#>     objectives: active binding
#>     output: active binding
#>     path: /home/runner/work/_temp/Library/pegboard/lesson-fragment ...
#>     protect_curly: function () 
#>     protect_math: function () 
#>     protect_unescaped: function () 
#>     questions: active binding
#>     remove_error: function () 
#>     remove_output: function () 
#>     reset: function () 
#>     show: function () 
#>     show_problems: active binding
#>     solutions: active binding
#>     summary: function () 
#>     tags: active binding
#>     tail: function (n = 6L) 
#>     unblock: function (token = "#'") 
#>     use_dovetail: function () 
#>     use_sandpaper: function (rmd = FALSE, yml = list()) 
#>     validate_divs: function (warn = TRUE) 
#>     validate_headings: function (verbose = TRUE, warn = TRUE) 
#>     validate_links: function (warn = TRUE) 
#>     warning: active binding
#>     write: function (path = NULL, format = "md", edit = FALSE) 
#>     yaml: --- title: "For Loops" teaching: 10 exercises: 15 questi ...
#>   Private:
#>     clear_yaml_item: function (what) 
#>     deep_clone: function (name, value) 
#>     encoding: UTF-8
#>     md_lines: function (path = NULL, stylesheet = NULL) 
#>     mutations: FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#>     problems: list
#>     record_problem: function (x) 
#>     sourcepos: TRUE
#> 
#> $`14-looping-data-sets.md`
#> <Episode>
#>   Inherits from: <yarn>
#>   Public:
#>     add_md: function (md, where = 0L) 
#>     body: xml_document, xml_node
#>     challenges: active binding
#>     clone: function (deep = FALSE) 
#>     code: active binding
#>     confirm_sandpaper: function () 
#>     error: active binding
#>     get_blocks: function (type = NULL, level = 1L) 
#>     get_challenge_graph: function (recurse = TRUE) 
#>     get_divs: function (type = NULL, include = FALSE) 
#>     get_images: function (process = FALSE) 
#>     get_yaml: function () 
#>     handout: function (path = NULL, solutions = FALSE) 
#>     head: function (n = 6L) 
#>     headings: active binding
#>     images: active binding
#>     initialize: function (path = NULL, process_tags = TRUE, fix_links = TRUE, 
#>     isolate_blocks: function () 
#>     keypoints: active binding
#>     label_divs: function () 
#>     lesson: active binding
#>     links: active binding
#>     move_keypoints: function () 
#>     move_objectives: function () 
#>     move_questions: function () 
#>     name: active binding
#>     ns: http://commonmark.org/xml/1.0
#>     objectives: active binding
#>     output: active binding
#>     path: /home/runner/work/_temp/Library/pegboard/lesson-fragment ...
#>     protect_curly: function () 
#>     protect_math: function () 
#>     protect_unescaped: function () 
#>     questions: active binding
#>     remove_error: function () 
#>     remove_output: function () 
#>     reset: function () 
#>     show: function () 
#>     show_problems: active binding
#>     solutions: active binding
#>     summary: function () 
#>     tags: active binding
#>     tail: function (n = 6L) 
#>     unblock: function (token = "#'") 
#>     use_dovetail: function () 
#>     use_sandpaper: function (rmd = FALSE, yml = list()) 
#>     validate_divs: function (warn = TRUE) 
#>     validate_headings: function (verbose = TRUE, warn = TRUE) 
#>     validate_links: function (warn = TRUE) 
#>     warning: active binding
#>     write: function (path = NULL, format = "md", edit = FALSE) 
#>     yaml: --- title: "Looping Over Data Sets" teaching: 5 exercise ...
#>   Private:
#>     clear_yaml_item: function (what) 
#>     deep_clone: function (name, value) 
#>     encoding: UTF-8
#>     md_lines: function (path = NULL, stylesheet = NULL) 
#>     mutations: FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#>     problems: list
#>     record_problem: function (x) 
#>     sourcepos: TRUE
#> 
#> $`17-scope.md`
#> <Episode>
#>   Inherits from: <yarn>
#>   Public:
#>     add_md: function (md, where = 0L) 
#>     body: xml_document, xml_node
#>     challenges: active binding
#>     clone: function (deep = FALSE) 
#>     code: active binding
#>     confirm_sandpaper: function () 
#>     error: active binding
#>     get_blocks: function (type = NULL, level = 1L) 
#>     get_challenge_graph: function (recurse = TRUE) 
#>     get_divs: function (type = NULL, include = FALSE) 
#>     get_images: function (process = FALSE) 
#>     get_yaml: function () 
#>     handout: function (path = NULL, solutions = FALSE) 
#>     head: function (n = 6L) 
#>     headings: active binding
#>     images: active binding
#>     initialize: function (path = NULL, process_tags = TRUE, fix_links = TRUE, 
#>     isolate_blocks: function () 
#>     keypoints: active binding
#>     label_divs: function () 
#>     lesson: active binding
#>     links: active binding
#>     move_keypoints: function () 
#>     move_objectives: function () 
#>     move_questions: function () 
#>     name: active binding
#>     ns: http://commonmark.org/xml/1.0
#>     objectives: active binding
#>     output: active binding
#>     path: /home/runner/work/_temp/Library/pegboard/lesson-fragment ...
#>     protect_curly: function () 
#>     protect_math: function () 
#>     protect_unescaped: function () 
#>     questions: active binding
#>     remove_error: function () 
#>     remove_output: function () 
#>     reset: function () 
#>     show: function () 
#>     show_problems: active binding
#>     solutions: active binding
#>     summary: function () 
#>     tags: active binding
#>     tail: function (n = 6L) 
#>     unblock: function (token = "#'") 
#>     use_dovetail: function () 
#>     use_sandpaper: function (rmd = FALSE, yml = list()) 
#>     validate_divs: function (warn = TRUE) 
#>     validate_headings: function (verbose = TRUE, warn = TRUE) 
#>     validate_links: function (warn = TRUE) 
#>     warning: active binding
#>     write: function (path = NULL, format = "md", edit = FALSE) 
#>     yaml: --- title: "Variable Scope" teaching: 10 exercises: 10 q ...
#>   Private:
#>     clear_yaml_item: function (what) 
#>     deep_clone: function (name, value) 
#>     encoding: UTF-8
#>     md_lines: function (path = NULL, stylesheet = NULL) 
#>     mutations: FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
#>     problems: list
#>     record_problem: function (x) 
#>     sourcepos: TRUE
#> 

## ------------------------------------------------
## Method `Lesson$get`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$get("error") # error code blocks
#> $`10-lunch.md`
#> {xml_nodeset (0)}
#> 
#> $`12-for-loops.md`
#> {xml_nodeset (2)}
#> [1] <code_block sourcepos="58:1-60:3" xml:space="preserve" name="" ktag="{: . ...
#> [2] <code_block sourcepos="70:1-75:3" xml:space="preserve" name="" ktag="{: . ...
#> 
#> $`14-looping-data-sets.md`
#> {xml_nodeset (0)}
#> 
#> $`17-scope.md`
#> {xml_nodeset (2)}
#> [1] <code_block sourcepos="37:1-42:3" xml:space="preserve" name="" ktag="{: . ...
#> [2] <code_block sourcepos="73:3-93:5" xml:space="preserve" name="" ktag="{: . ...
#> 
frg$get("links") # links
#> $`10-lunch.md`
#> {xml_nodeset (0)}
#> 
#> $`12-for-loops.md`
#> {xml_nodeset (1)}
#> [1] <link sourcepos="115:27-115:90" destination="https://docs.python.org/3/li ...
#> 
#> $`14-looping-data-sets.md`
#> {xml_nodeset (8)}
#> [1] <link sourcepos="36:8-36:75" destination="https://docs.python.org/3/libra ...
#> [2] <link sourcepos="42:25-42:77" destination="https://docs.python.org/3/libr ...
#> [3] <link sourcepos="43:9-43:61" destination="https://docs.python.org/3/libra ...
#> [4] <link sourcepos="125:17-125:118" destination="https://pandas.pydata.org/p ...
#> [5] <link sourcepos="148:62-148:129" destination="https://docs.python.org/3/l ...
#> [6] <link xmlns="http://commonmark.org/xml/1.0" destination="{{ page.root }}/ ...
#> [7] <link xmlns="http://commonmark.org/xml/1.0" destination="{{ site.swc_page ...
#> [8] <link xmlns="http://commonmark.org/xml/1.0" destination="{{ page.root }}{ ...
#> 
#> $`17-scope.md`
#> {xml_nodeset (0)}
#> 

## ------------------------------------------------
## Method `Lesson$summary`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$summary() # episode summary (default)
#> ! Summary not guaranteed for styles-based lessons
#> # A tibble: 4 × 12
#>   page        secti…¹ headi…² callo…³ chall…⁴ solut…⁵  code output warning error
#>   <chr>         <int>   <int>   <int>   <int>   <int> <int>  <int>   <int> <int>
#> 1 10-lunch.md       0       0       0       0       0     0      0       0     0
#> 2 12-for-loo…      24      24       7       7      10    32      4       0     2
#> 3 14-looping…       9      10       3       3       3    11      4       0     0
#> 4 17-scope.md       3       3       2       2       0     6      1       0     2
#> # … with 2 more variables: images <int>, links <int>, and abbreviated variable
#> #   names ¹​sections, ²​headings, ³​callouts, ⁴​challenges, ⁵​solutions

## ------------------------------------------------
## Method `Lesson$thin`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$thin()
#> Removing 1 episode: 10-lunch.md

## ------------------------------------------------
## Method `Lesson$reset`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$episodes[[1]]$body
#> {xml_document}
#> <document sourcepos="1:1-4:131" xmlns="http://commonmark.org/xml/1.0">
#> [1] <paragraph sourcepos="1:1-1:49">\n  <text sourcepos="1:1-1:49" xml:space= ...
#> [2] <list sourcepos="2:1-4:131" type="bullet" tight="true">\n  <item sourcepo ...
frg$isolate_blocks()$episodes[[1]]$body # empty
#> {xml_document}
#> <document sourcepos="1:1-4:131" xmlns="http://commonmark.org/xml/1.0">
frg$reset()$episodes[[1]]$body # reset
#> {xml_document}
#> <document sourcepos="1:1-4:131" xmlns="http://commonmark.org/xml/1.0">
#> [1] <paragraph sourcepos="1:1-1:49">\n  <text sourcepos="1:1-1:49" xml:space= ...
#> [2] <list sourcepos="2:1-4:131" type="bullet" tight="true">\n  <item sourcepo ...

## ------------------------------------------------
## Method `Lesson$isolate_blocks`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$isolate_blocks()$body # only one challenge block_quote
#> NULL

## ------------------------------------------------
## Method `Lesson$handout`
## ------------------------------------------------

lsn <- Lesson$new(lesson_fragment("sandpaper-fragment"), jekyll = FALSE)
cat(lsn$handout())
#> ## Using RMarkdown
#> 
#> ## Challenge 1: Can you do it?
#> 
#> What is the output of this command?
#> 
#> ```{r, eval=FALSE}
#> paste("This", "new", "template", "looks", "good")
#> ```
cat(lsn$handout(solution = TRUE))
#> ## Using RMarkdown
#> 
#> ## Challenge 1: Can you do it?
#> 
#> What is the output of this command?
#> 
#> ```{r, eval=FALSE}
#> paste("This", "new", "template", "looks", "good")
#> ```
#> 
#> :::::::::::::::::::::::: solution
#> 
#> ## Output
#> 
#> ```{r, echo=FALSE}
#> paste("This", "new", "template", "looks", "good")
#> ```
#> 
#> ::::::::::::::::::::::::::::::::::
#> 
#> ## Challenge 2: how do you nest solutions within challenge blocks?
#> 
#> :::::::::::::::::::::::: solution
#> 
#> You can add a line with at least three colons and a `solution` tag.

## ------------------------------------------------
## Method `Lesson$validate_headings`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$validate_headings()
#> ── Heading structure ───────────────────────────────────────────────────────────
#> # Episode: “For Loops” 
#> ├─## A for loop executes commands once for each value in a collection. 
#> ├─## A for loop is made up of a collection, a loop variable, and a body. 
#> ├─## The first line of the for loop must end with a colon, and the body must be 
#> ├─## Loop variables can be called anything. 
#> ├─## The body of a loop can contain many statements. 
#> ├─## Use range to iterate over a sequence of numbers. 
#> ├─## The Accumulator pattern turns many values into one. 
#> ├─## Classifying Errors 
#> ├─## Solution  (duplicated)
#> ├─## Tracing Execution 
#> ├─## Solution  (duplicated)
#> ├─## Reversing a String 
#> ├─## Solution  (duplicated)
#> ├─## Practice Accumulating 
#> ├─## Solution  (duplicated)
#> ├─## Solution  (duplicated)
#> ├─## Solution  (duplicated)
#> ├─## Solution  (duplicated)
#> ├─## Cumulative Sum 
#> ├─## Solution  (duplicated)
#> ├─## Identifying Variable Name Errors 
#> ├─## Solution  (duplicated)
#> ├─## Identifying Item Errors 
#> └─## Solution  (duplicated)
#> ────────────────────────────────────────────────────────────────────────────────
#> ── Heading structure ───────────────────────────────────────────────────────────
#> # Episode: “Looping Over Data Sets” 
#> ├─## Use a for loop to process files given a list of their names. 
#> ├─## Use glob.glob to find sets of files whose names match a pattern. 
#> ├─## Use glob and for to process batches of files. 
#> ├─## Determining Matches 
#> ├─## Solution  (duplicated)
#> ├─## Minimum File Size 
#> ├─## Solution  (duplicated)
#> ├─## Comparing Data 
#> └─## Solution  (duplicated)
#>   └─### ZNK test links and images 
#> ────────────────────────────────────────────────────────────────────────────────
#> ! There were errors in 13/37 headings
#> ◌ Headings must be unique
#> <https://webaim.org/techniques/semanticstructure/#headings>
#> 
#> ::warning file=_episodes/12-for-loops.md,line=183:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=200:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=227:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=252:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=270:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=289:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=305:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=336:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=371:: (duplicated)
#> ::warning file=_episodes/12-for-loops.md,line=400:: (duplicated)
#> ::warning file=_episodes/14-looping-data-sets.md,line=119:: (duplicated)
#> ::warning file=_episodes/14-looping-data-sets.md,line=143:: (duplicated)
#> ::warning file=_episodes/14-looping-data-sets.md,line=162:: (duplicated)

## ------------------------------------------------
## Method `Lesson$validate_divs`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$validate_divs()

## ------------------------------------------------
## Method `Lesson$validate_links`
## ------------------------------------------------

frg <- Lesson$new(lesson_fragment())
frg$validate_links()
#> ! There were errors in 4/14 links
#> ◌ Some linked internal files do not exist
#> ◌ Images need alt-text
#> <https://webaim.org/techniques/hypertext/link_text#alt_link>
#> 
#> ::warning file=_episodes/14-looping-data-sets.md,line=191:: [missing file]
#> ../no-workie.svg
#> ::warning file=_episodes/14-looping-data-sets.md,line=195:: [image missing
#> alt-text] https://carpentries.org/assets/img/TheCarpentries.svg
#> ::warning file=_episodes/14-looping-data-sets.md,line=197:: [missing file]
#> ../no-workie.svg [image missing alt-text] ../no-workie.svg
#> ::warning file=_episodes/14-looping-data-sets.md,line=NA:: [image missing
#> alt-text] { page.root }/no-workie.svg