[−][src]Trait wast::parser::Peek
A trait for types which be used to "peek" to see if they're the next token
in an input stream of [Parser].
Often when implementing [Parse] you'll need to query what the next token
in the stream is to figure out what to parse next. This [Peek] trait
defines the set of types that can be tested whether they're the next token
in the input stream.
Implementations of [Peek] should only be present on types that consume
exactly one token (not zero, not more, exactly one). Types implementing
[Peek] should also typically implement [Parse] should also typically
implement [Parse].
See the documentation of [Parser::peek] for example usage.
Required methods
fn peek(cursor: Cursor) -> bool
Tests to see whether this token is the first token within the [Cursor]
specified.
Returns true if [Parse] for this type is highly likely to succeed
failing no other error conditions happening (like an integer literal
being too big).
fn display() -> &'static str
Returns a human-readable name of this token to display when generating errors about this token missing.