Enum Delimiter 

pub enum Delimiter {
    Parenthesis,
    Brace,
    Bracket,
    Invisible(InvisibleOrigin),
}

Describes how a sequence of token trees is delimited. Cannot use proc_macro::Delimiter directly because this structure should implement some additional traits.

Variants

Parenthesis

( ... )

Brace

{ ... }

Bracket

[ ... ]

Invisible(InvisibleOrigin)

∅ ... ∅ An invisible delimiter, that may, for example, appear around tokens coming from a “macro variable” $var. It is important to preserve operator priorities in cases like $var * 3 where $var is 1 + 2. Invisible delimiters might not survive roundtrip of a token stream through a string.