Module flexi_parse::group

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Expand description

Streams of tokens delimited by punctuation.

The core of this module is the Group type, which represents a delimited group of tokens.

Basic usage

let group: Group<Parentheses> = parse_string("(3)".to_string()).unwrap();
let lit: LitInt = parse(group.into_token_stream()).unwrap();
assert_eq!(lit.value(), 3);

The Delimiter trait

The Delimiter trait is used to provide information to Group on how to parse the delimiters. It is typically implemented for newtype structs wrapping a span.

Example

Below is an example of a custom set of delimiters.

struct AtDelimiters(Span);

impl From<Span> for AtDelimiters {
    fn from(value: Span) -> Self {
        AtDelimiters(value)
    }
}

impl Delimiters for AtDelimiters {
    type Start = Punct!["@"];
    type End = Punct!["@"];
    const CAN_NEST: bool = false;

    fn span(&self) -> &Span {
        &self.0
    }
}

let group: Group<AtDelimiters> = parse_string("@hello@".to_string()).unwrap();
let hello: Ident = parse(group.into_token_stream()).unwrap();
assert_eq!(hello.string(), "hello");

Structs

Traits

  • Delimiters
    A trait for types that represent the delimiters of a group.