Crate katex_parser 

A Rust port of the KaTeX parser: lexes and parses LaTeX math expressions with macro expansion into a typed ParseNode AST, and renders that AST to Unicode text.

The parser mirrors the MoonBit katex-parser package (itself a port of KaTeX). Entry points:

• parse / parse_with_specs — parse LaTeX into a ParseNode list.
• render — render a parsed node list as Unicode text.
• Settings — parser configuration (display mode, macros, strictness, trust policy, and a persistent macro store).

Structs

ArrayEnvironmentOptions

Options controlling how an array environment is parsed.

Block

A 2D text block where every line has equal width. Supports vertical stacking, horizontal juxtaposition with baseline alignment, and delimiter wrapping — building blocks for block-mode Unicode rendering of matrices, fractions, delimited expressions, etc.

Diagnostic

Diagnostic information attached to an offending token.

EnvironmentContext

Per-environment-call context: static data about the environment.

EnvironmentRegistry

A map from environment names to their specs.

EnvironmentSpec

The declaration of an environment (name, arguments, handler).

FunctionContext

Per-function-call context: static data about the function being parsed.

FunctionRegistry

A map from function names to their specs.

FunctionSpec

The declaration of a function (name, arguments, handler).

MacroExpansion

A macro expansion with its argument count and delimiters.

Macros

A persistent macro store shared across parses.

Measurement

A dimension with a numeric value and a unit (e.g. em, pt).

RenderConfig

Configuration for the Unicode renderer.

Settings

Parser configuration: display mode, macros, strictness, trust, and limits.

SourceLocation

A span of the original input. start/end are char offsets into input.

SpacableItem

A renderable atom with its math class and baseline info.

SpacingSpec

Concrete space representations for a rendering backend. Different backends (unicode text, HTML/CSS, LaTeX) provide their own spec.

Token

A lexed or macro-expanded token.

Enums

ArgType

How a function argument should be parsed.

ArrayColumn

A column of an array environment: an alignment cell or a vertical separator.

AtomFamily

The math atom class of a symbol, used for spacing decisions.

ColumnSeparationType

How columns of an array are separated.

LapAlignment

Horizontal alignment of a Lap (mathllap/mathrlap/mathclap) node.

LineStyle

Glyph style for drawn lines: fraction bars, boxes, tables, etc.

MacroDefinition

A macro body: raw text or a pre-expanded token list.

Mode

The parsing mode: math or text.

OperatorContent

The body of an Op node: a symbol, a named operator, or an argument body.

ParseError

A parse failure, mirroring MoonBit’s ParseFailure suberror.

ParseNode

A parsed node in the LaTeX AST.

StrictResponse

The result of a strict-mode check: ignore, warn, or error.

Strictness

The strictness policy for LaTeX-incompatible input.

StyleLevel

The typesetting style level, as selected by \displaystyle and friends.

TrustContext

The context of a trust check for potentially unsafe commands.

TrustPolicy

The trust policy for commands that could be unsafe (\href, \url, HTML).

UnicodeScriptKind

Whether a Unicode script is a subscript or superscript.

Traits

EnvironmentParser

Callbacks the parser exposes to environment handlers.

FunctionParser

Callbacks the parser exposes to function handlers. &mut methods mutate parser state; &self methods are pure reads of settings/state.

Functions

atom_family_name

Converts AtomFamily to the corresponding spacing type string.

build_environment_registry

Builds an environment registry from the builtin specs plus caller-provided extension specs (which override builtins sharing the same name).

build_function_registry

Builds a function registry from the builtin specs plus caller-provided extension specs (e.g. \eval registered by the eval package).

cancel_bin_atoms

Apply bin cancellation: Mbin atoms become Mord in certain contexts.

command_name

Strips the leading backslash from a control-sequence label (\sin -> sin). Labels without a backslash are returned unchanged.

em_value

Converts a measurement to an em length: em passes through, mu uses the 18 mu per em ratio, and ex the standard 0.5 x-height ratio. Returns None for units with no fixed em relation (fill, pt, …).

is_null_delimiter

True for the null delimiter . used by \left. / \right., which renders as nothing in every backend.

join_with_spacing

Join spacable items into a string, inserting spacing between adjacent non-space atoms according to the given SpacingSpec.

katex_size_multiplier

The KaTeX font-size multiplier table (\tiny .. \Huge, including \sixptsize), indexed by the 1-based Sizing.size field. Sizes outside the table fall back to 1.0 (\normalsize).

line_style_frac_bar

The line character for a fraction bar under the given style.

math_choice_variant

Selects the body of a \mathchoice node for the current style level.

math_spacing

Look up spacing between two atom types.

parse

Parses input into a ParseNode list using the given settings. When settings.global_group is set and settings.macro_store is present, macros defined during the parse (e.g. via \newcommand) are written back into the caller’s store.

parse_with_specs

Parses input with caller-provided extension function/environment specs.

render

Renders parsed KaTeX nodes as Unicode text. Nodes without a direct Unicode rendering use UnicodeMath-style function syntax so that their structure is retained in plain text.

resolve_symbol

Resolves a TeX command name or raw Unicode string to its Unicode rendering via the parser’s symbol registry, falling back to the input itself.

supported_codepoint

True when the codepoint falls within one of the supported Unicode script blocks. Mirrors KaTeX’s supportedCodepoint (unicodeScripts.ts).

token_location

Returns the source location of a token, if any.

unicode_font_character

Returns the Unicode mathematical alphanumeric character for a given font style and ASCII letter/digit, or None when no mapping exists.

unicode_script_character

Returns the Unicode superscript or subscript character for replacement.

unicode_symbol

Returns a registered symbol’s Unicode replacement, if it has one.

unicode_text_spacing

Unicode text spacing: regular spaces for thick/medium, thin and after operators.

Type Aliases

EnvironmentHandler

An environment handler implementation.

FunctionHandler

A function handler implementation.

StrictHandler

StrictWarningHandler

A callback invoked when strict mode produces a warning.

TrustHandler

A callback deciding whether a trust context is accepted.