Quarto Documentation

The @quarto/external-observablehq-stdlib package is a fork of @observablehq/stdlib specifically modified to ensure compatibility with the RStudio IDE. It addresses two primary constraints of the RStudio environment:

1. Require Compatibility: The build process (producing dist/stdlib.js) utilizes a fork of d3-require. This enables a require() function that operates correctly both within the Observable runtime and inside IPython's HTMLwidgets.
2. JS Stdlib Compatibility: To avoid errors caused by the older version of the JavaScript standard library used in the RStudio IDE, this fork avoids calling Object.fromEntries.

The parser handles special OJS syntax like viewof and imports with injections:

ViewExpressions

When a cell uses the viewof syntax (e.g., viewof x = ...), the cell.id becomes a ViewExpression. A ViewExpression contains an id which is the underlying Identifier.

ImportDeclarations

• ImportSpecifier: Each specifier in an import has a view boolean indicating if it specifies a view (e.g., import {viewof foo} ...).
• Injections: If an import uses a with clause (e.g., import {chart} with {sales as data} ...), the declaration.injections property will contain an array of ImportSpecifier nodes. In these nodes, imported and local are reversed relative to standard imports: they represent the perspective of the module being imported.

Slide show structure is determined by heading levels and horizontal rules:

• Slide Level: The highest heading level followed immediately by content. This can be overridden with the --slide-level option.
• Horizontal Rules: A --- always starts a new slide.
• Headings at Slide Level: Starts a new slide.
• Headings below Slide Level: Create content within a slide (e.g., in beamer, these create block, exampleblock, or alertblock environments).
• Headings above Slide Level: Create "title slides" to break the show into sections.
• Title Page: Automatically generated from the document's title metadata block.

Note for reveal.js: If slide level is 2, it produces a 2D layout (level-1 is horizontal, level-2 is vertical). For a 1D layout, use --slide-level=0.

Pandoc templates use specific delimiters to identify variables and control structures.

• Comments: Use $-- at the start of a line to create a comment. Everything from $-- to the end of the line is omitted from the output.
• Delimiters: You can use either $ ... $ or ${ ... } to mark variables and control structures. The opening and closing delimiters must match within a single expression. Spaces or tabs following the opening or preceding the closing delimiter are ignored.
• Literal Dollar Signs: To include a literal $ in your document, use $$.

$-- This is a comment
$foo$
${bar}
$$ (literal dollar sign)

With the implicit_header_references extension enabled, you can link to a heading by using its exact text as a reference link, rather than providing an explicit #identifier.

Example: If you have a heading # Heading identifiers in HTML, you can link to it using [Heading identifiers in HTML] or [Heading identifiers in HTML][].

Precedence: Explicit link reference definitions (e.g., [foo]: bar) always take priority over implicit heading references.

The core abstraction of this library is the MappedString interface. It wraps a standard string and provides a map function that translates character indices from the current (transformed) string back to their original positions in the source string.

This allows you to perform complex text processing pipelines while maintaining perfect source location fidelity. When you perform operations like mappedSubstring, mappedReplace, mappedTrim, or skipRegexp, the library ensures that the mapping information is preserved through each step. This is essential for accurate error reporting, as it allows you to report the exact line and column in the original source even after the text has been heavily manipulated.

The smart extension interprets straight quotes as curly quotes, --- as em-dashes, -- as en-dashes, and ... as ellipses. It also inserts nonbreaking spaces after certain abbreviations (e.g., "Mr.").

Supported Formats:

• Input: markdown, commonmark, latex, mediawiki, org, rst, twiki, html
• Output: markdown, latex, context, rst (enabled by default in markdown, latex, and context)

Note on Writing Markdown: When writing Markdown, the smart extension has the reverse effect: what would have been curly quotes in the source will be output as straight quotes.

A caption can be added to any of the four table types (simple, multiline, grid, or pipe).

A caption is a paragraph that begins with the string Table: (case-insensitive, e.g., table:) or just a colon :. The caption can appear either before or after the table and will be stripped from the table structure itself.

| Header | Col |
|-------|-----|
| Val   | 1   |

: This is a caption.