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 is not reflowed to the width: the keys stay together as one atom; only incidental source line breaks inside the braces 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.

Weaker than TokenList about where the content may go (a keyval list expands one key per line at the width rather than staying one atom), stronger about what may be inserted between entries.

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