Enum Pattern 

pub enum Pattern {
    Empty,
    Ident(Ident),
    Literal(Literal),
    Series(Vec<Pattern>),
    Choice(Vec<Pattern>),
    Repeat {
        pattern: Box<Pattern>,
        repeat: Repeat,
    },
    Predicate {
        pred: Box<Pattern>,
        expr: Box<Pattern>,
    },
}

Variants

Empty

Ident(Ident)

A rule or terminal (e.g. L_PAREN)

Literal(Literal)

A literal string (e.g. "keyword")

Series(Vec<Pattern>)

Multiple patterns matched in a row (e.g. L_PAREN IDENT R_PAREN)

Choice(Vec<Pattern>)

A choice between multiple patterns (e.g. "public" | "private")

Repeat

A repetition of a pattern group (e.g. (IDENT COLON type_expr COMMA)+)

Fields

pattern: Box<Pattern>

repeat: Repeat

Predicate

A pre-condition to check before parsing a tree, typically to resolve syntactic ambiguity; e.g. the (...) => ... in:

lhs_expression: (“new” expression) => newExpression | expression ;

Fields

pred: Box<Pattern>

expr: Box<Pattern>

Implementations

impl Pattern

pub fn is_empty(&self) -> bool

pub fn flatten_once(self) -> Pattern

Unwraps the top-level of the pattern tree, if possible.

Trait Implementations

impl Debug for Pattern

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

Formats the value using the given formatter.