Enum TokenKind 

#[non_exhaustive]
pub enum TokenKind {
    Keyword(Keyword),
    Identifier,
    EscapedIdentifier,
    Parameter,
    Integer,
    HexInteger,
    OctalInteger,
    Float,
    String,
    LeftParen,
    RightParen,
    LeftBracket,
    RightBracket,
    LeftBrace,
    RightBrace,
    Comma,
    Dot,
    DotDot,
    Colon,
    DoubleColon,
    Semicolon,
    Pipe,
    DoublePipe,
    Ampersand,
    Question,
    Dollar,
    Plus,
    Minus,
    Star,
    Slash,
    Percent,
    Caret,
    Bang,
    Equal,
    NotEqual,
    Less,
    LessEqual,
    Greater,
    GreaterEqual,
    PlusEqual,
    FatArrow,
    RegexMatch,
    LeftArrow,
    RightArrow,
    Whitespace,
    LineComment,
    BlockComment,
    Invalid,
}

A lexical token class understood by the openCypher parser.

Keyword recognition is case-insensitive. The parser reclassifies non-reserved Keyword tokens contextually when a name is required.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Keyword(Keyword)

A case-insensitive language keyword.

Identifier

An unescaped symbolic name.

EscapedIdentifier

A backtick-delimited symbolic name.

Parameter

A parameter whose separated name is unescaped, such as $name, $123, or $1_name.

Integer

A base-ten integer literal.

HexInteger

A hexadecimal integer literal.

OctalInteger

An octal integer literal.

Float

A decimal floating-point literal, optionally with an exponent.

String

A single- or double-quoted string literal.

LeftParen

RightParen

LeftBracket

RightBracket

LeftBrace

RightBrace

Comma

Dot

DotDot

Colon

DoubleColon

Semicolon

Pipe

DoublePipe

Ampersand

Question

Dollar

A bare $; the parser combines it with a following backtick-delimited identifier to form an escaped parameter name.

Plus

Minus

Star

Slash

Percent

Caret

Bang

Equal

NotEqual

Less

LessEqual

Greater

GreaterEqual

PlusEqual

FatArrow

RegexMatch

LeftArrow

A contiguous <-; spaced or comment-separated forms remain separate Less and Minus tokens.

RightArrow

A contiguous ->; spaced or comment-separated forms remain separate Minus and Greater tokens.

Whitespace

One or more Unicode whitespace characters.

LineComment

A // comment, including its marker but excluding a line terminator.

BlockComment

A /* ... */ comment, including its delimiters.

Invalid

A source region which cannot begin any valid token.

Implementations

impl TokenKind

pub const fn is_trivia(self) -> bool

Returns true for whitespace and comments.

pub const fn is_literal(self) -> bool

Returns true for literal tokens.

pub const fn display_name(self) -> &'static str

Returns a concise, user-facing name suitable for diagnostics.

Trait Implementations

impl Clone for TokenKind

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for TokenKind

impl Debug for TokenKind

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

Formats the value using the given formatter.

impl Display for TokenKind

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

Formats the value using the given formatter.

impl Eq for TokenKind

impl Hash for TokenKind

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for TokenKind

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TokenKind