4. Output Formats

When the source is parsed, and have been processed it is time to render the output. We will consider the following source snippet:

# # Rational numbers
#
# In julia rational numbers can be constructed with the `//` operator.
# Lets define two rational numbers, `x` and `y`:

x = 1//3
#-
y = 2//5

# When adding `x` and `y` together we obtain a new rational number:

z = x + y

and see how this is rendered in each of the output formats.

4.1. Markdown Output

Markdown output is generated by Literate.markdown. The (default) markdown output of the source snippet above is as follows:

```@meta
EditURL = "@__REPO_ROOT_URL__/src/outputformats.jl"
```

# Rational numbers

In julia rational numbers can be constructed with the `//` operator.
Lets define two rational numbers, `x` and `y`:

```@example name
x = 1//3
```

```@example name
y = 2//5
```

When adding `x` and `y` together we obtain a new rational number:

```@example name
z = x + y
```

We note that lines starting with # are printed as regular markdown, and the code lines have been wrapped in @example blocks. We also note that an @meta block have been added, that sets the EditURL variable. This is used by Documenter to redirect the "Edit on GitHub" link for the page, see Interaction with Documenter.

It possible to configure Literate.markdown to also evaluate code snippets, capture the result and include it in the output, by passing execute=true as a keyword argument. The result of the first code-block in the example above would then become

```julia
x = 1//3
```
```
1//3
```

In this example the output is just plain text. However, if the resulting value of the code block can be displayed as an image (png or jpeg) Literate will include the image representation of the output.

Note

Since Documenter executes and captures results of @example block it is not necessary to use execute=true for markdown output that is meant to be used as input to Documenter.

Literate 2.4

Code execution of markdown output requires at least Literate version 2.4.

See the section about Configuration for more information about how to configure the behavior and resulting output of Literate.markdown.

Literate.markdownFunction
Literate.markdown(inputfile, outputdir=pwd(); config::Dict=Dict(), kwargs...)

Generate a markdown file from inputfile and write the result to the directory outputdir.

Literate 2.5

Default output directory pwd requires at least Literate version 2.5.

See the manual section on Configuration for documentation of possible configuration with config and other keyword arguments.

4.2. Notebook Output

Notebook output is generated by Literate.notebook. The (default) notebook output of the source snippet can be seen here: notebook.ipynb.

We note that lines starting with # are placed in markdown cells, and the code lines have been placed in code cells. By default the notebook is also executed and output cells populated. The current working directory is set to the specified output directory the notebook is executed.

See the section about Configuration for how to configure the behavior and resulting output of Literate.notebook.

Literate.notebookFunction
Literate.notebook(inputfile, outputdir=pwd(); config::Dict=Dict(), kwargs...)

Generate a notebook from inputfile and write the result to outputdir.

Literate 2.5

Default output directory pwd requires at least Literate version 2.5.

See the manual section on Configuration for documentation of possible configuration with config and other keyword arguments.

Notebook metadata

Jupyter notebook cells (both code cells and markdown cells) can contain metadata. This is enabled in Literate by the %% token, similar to Jupytext. The format is as follows

%% optional ignored text [type] {optional metadata JSON}

Cell metadata can, for example, be used for nbgrader and the reveal.js notebook extension RISE.

The following would create a 3 slide deck with RISE:

#nb # %% A slide [markdown] {"slideshow": {"slide_type": "slide"}}
# # Some title
#
# We're using `#nb` so the metadata is only included in notebook output

#nb %% A slide [code] {"slideshow": {"slide_type": "fragment"}}
x = 1//3
y = 2//5

#nb # %% A slide [markdown] {"slideshow": {"slide_type": "subslide"}}
# For more information about RISE, see [the docs](https://rise.readthedocs.io/en/stable/usage.html)

4.3. Script Output

Script output is generated by Literate.script. The (default) script output of the source snippet above is as follows:

x = 1//3

y = 2//5

z = x + y

We note that lines starting with # are removed and only the code lines have been kept.

See the section about Configuration for how to configure the behavior and resulting output of Literate.script.

Literate.scriptFunction
Literate.script(inputfile, outputdir=pwd(); config::Dict=Dict(), kwargs...)

Generate a plain script file from inputfile and write the result to outputdir.

Literate 2.5

Default output directory pwd requires at least Literate version 2.5.

See the manual section on Configuration for documentation of possible configuration with config and other keyword arguments.

4.4. Configuration

The behavior of Literate.markdown, Literate.notebook and Literate.script can be configured by keyword arguments. There are two ways to do this; pass config::Dict as a keyword argument, or pass individual keyword arguments.

Literate 2.2

Passing configuration as a dictionary requires at least Literate version 2.2.

Configuration precedence

Individual keyword arguments takes precedence over the config dictionary, so for e.g. Literate.markdown(...; config = Dict("name" => "hello"), name = "world") the resulting configuration for name will be "world". Both individual keyword arguments and the config dictionary takes precedence over the default.

Available configurations with description and default values are given in the reference for Literate.DEFAULT_CONFIGURATION just below.

Literate.DEFAULT_CONFIGURATIONConstant
DEFAULT_CONFIGURATION

Default configuration for Literate.markdown, Literate.notebook and Literate.script which is used for everything not specified by the user. See the manual section about Configuration for more information.

Configuration keyDescriptionDefault valueComment
nameName of the output file (excluding file extension).filename(inputfile)
preprocessCustom preprocessing function mapping String to String.identitySee Custom pre- and post-processing.
postprocessCustom preprocessing function mapping String to String.identitySee Custom pre- and post-processing.
documenterBoolean signaling that the source contains Documenter.jl elements.trueSee Interaction with Documenter.
creditBoolean for controlling the addition of This file was generated with Literate.jl ... to the bottom of the page. If you find Literate.jl useful then feel free to keep this.true
keep_commentsWhen true, keeps markdown lines as comments in the output script.falseOnly applicable for Literate.script.
executeWhether to execute and capture the output.true (notebook), false (markdown)Only applicable for Literate.notebook and Literate.markdown. For markdown this requires at least Literate 2.4.
codefencePair containing opening and closing fence for wrapping code blocks."```julia" => "```"If documenter is true the default is "```@example"=>"```".
devurlURL for "in-development" docs."dev"See Documenter docs. Unused if repo_root_url/nbviewer_root_url/binder_root_url are set.
repo_root_urlURL to the root of the repository.-Determined automatically on Travis CI, GitHub Actions and GitLab CI. Used for @__REPO_ROOT_URL__.
nbviewer_root_urlURL to the root of the repository as seen on nbviewer.-Determined automatically on Travis CI, GitHub Actions and GitLab CI. Used for @__NBVIEWER_ROOT_URL__.
binder_root_urlURL to the root of the repository as seen on mybinder.-Determined automatically on Travis CI, GitHub Actions and GitLab CI. Used for @__BINDER_ROOT_URL__.
repo_root_pathFilepath to the root of the repository.-Determined automatically on Travis CI, GitHub Actions and GitLab CI. Used for computing Documenters EditURL.