Struct NonParseable 

pub struct NonParseable;

A unit that can not be parsed. This is useful as diagnostic placeholder for parsers that are (yet) unimplemented. The nonparseable feature flag controls if Parser and ToTokens will be implemented for it. This is useful in release builds that should not have any NonParseable left behind.

Panics

Only when the nonparseable feature flag is set:

• NonParseable will panic when calling Parser::parser().
• NonParseable tokens can not be emitted and will panic when calling ToTokens::to_tokens().

Otherwise Parser and ToTokens are not implemented and will result in a compile time error.

Example

let mut tokens = "something".to_token_iter();
let nonparseable: NonParseable = tokens.parse().unwrap();

Trait Implementations

impl Clone for NonParseable

fn clone(&self) -> NonParseable

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NonParseable

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

Formats the value using the given formatter.

impl Parser for NonParseable

Available on crate feature nonparseable only.

fn parser(_tokens: &mut TokenIter) -> Result<NonParseable, Error>

The actual parsing function that must be implemented. This mutates the tokens iterator directly. It should not be called from user code except for implementing parsers itself and then only when the rules below are followed.

impl ToTokens for NonParseable

Available on crate feature nonparseable only.

fn to_tokens(&self, _tokens: &mut TokenStream)

Write &self to the given TokenStream.

fn to_token_iter(&self) -> TokenIter

Convert &self into a TokenIter object.

fn into_token_iter(self) -> TokenIter

where Self: Sized,

Convert self into a TokenIter object.

fn to_token_stream(&self) -> TokenStream

Convert &self into a TokenStream object.

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Convert self into a TokenStream object.

fn tokens_to_string(&self) -> String

Convert &self into a String object. This is mostly used in the test suite to compare the outputs. When the input is a &str then this parses it and returns a normalized String.