Enum ContentKind 

pub enum ContentKind {
    Opaque,
    Prose,
    TokenList,
    Keyval,
}

How the formatter treats an argument’s content — its whitespace and break policy. This metadata is for formatter consumers; the parser ignores it.

Variants

Opaque

Left exactly as authored: names, identifiers, code, or option lists (\label, the \newcommand body). The default, so an unmarked argument never reflows — for most arguments interior whitespace can matter (a minipage/\parbox body, a label key).

Prose

Running prose the formatter may reflow to the line width (e.g. a \footnote/\caption body, a sectioning title).

TokenList

A comma-separated token list whose interior whitespace is insignificant, so the formatter may collapse a multi-line authored form to a single line (a \citep/\cite key list). Unlike Prose, the content participates in the surrounding paragraph fill only at its top-level commas, so an over-width citation can wrap between keys without splitting a key or detaching its delimiters. Incidental source line breaks are normalized away, so \citep{\n a,\n b\n} formats identically to \citep{a, b} (determinism).

Keyval

A key=value list consumed by a keyval-family processor — keyval, xkeyval, pgfkeys, l3keys, or LaTeX’s own option-list scanner — every one of which strips spaces around keys and values before acting on them. That is what licenses the formatter to break the list at a comma the author glued ([xmin=-5,xmax=5]), materializing a space token TeX will see: in a keyval argument the space is discarded, so the typeset output cannot change.

The distinction is load-bearing and was settled by compiling both spellings: keyval brackets (\usepackage, \includegraphics, tikz/pgfplots, lstlisting) render identically, while textual optionals do not (\item[red,green], \caption[short,list], \cite[see,also], and a \newcommand default all gain a visible space). So this flag must never be set on an argument whose content is typeset — hold it to the same curated standard as the math-env routing.

Unlike TokenList, which flows inline with its surrounding paragraph, a keyval list expands as its own delimited group.

Trait Implementations

impl Clone for ContentKind

fn clone(&self) -> ContentKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ContentKind

impl Debug for ContentKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ContentKind

fn default() -> ContentKind

Returns the “default value” for a type.

impl Eq for ContentKind

impl PartialEq for ContentKind

fn eq(&self, other: &ContentKind) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ContentKind