Struct parsel::ast::Eof

pub struct Eof;

Verifies that parsing reached the end of the input (i.e., the end of the parse stream at the current level of nesting). Useful for ensuring that an input or a group is fully parsed by preceding types.

Consumes no tokens when parsed, produces no tokens when printed.

// an empty string / token stream should trivially parse as `Eof`
let _: Eof = "".parse()?;
// so should an all-whitespace one
let _: Eof = "\r\n   ".parse()?;

#[derive(PartialEq, Eq, Debug, Parse)]
struct BoolAtEnd {
    value: LitBool,
    eof: Eof,
}

#[derive(PartialEq, Eq, Debug, Parse)]
enum BoolAtEndOrInt {
    Bool(BoolAtEnd),
    Int(LitInt),
}

let actual: Punctuated<BoolAtEndOrInt, Comma> = "2, 46, 802, false".parse()?;
let actual: Vec<_> = actual.into_iter().collect();
let expected = [
    BoolAtEndOrInt::Int(LitInt::from(2)),
    BoolAtEndOrInt::Int(LitInt::from(46)),
    BoolAtEndOrInt::Int(LitInt::from(802)),
    BoolAtEndOrInt::Bool(BoolAtEnd {
        value: LitBool::from(false),
        eof: Eof,
    }),
];
assert_eq!(actual, expected);

let bad: Result<Punctuated<BoolAtEndOrInt, Comma>> = "2, 46, false, 802".parse();
let message = bad.as_ref().unwrap_err().to_string();
assert!(
    message.contains("expected end of input"),
    "actual error: {}", message
);

Implementations

impl Eof

pub const fn new() -> Self

Trait Implementations

impl Clone for Eof

fn clone(&self) -> Eof

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Eof

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

Formats the value using the given formatter.

impl Default for Eof

fn default() -> Eof

Returns the “default value” for a type.

impl Display for Eof

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

Formats the value using the given formatter.

impl FromStr for Eof

type Err = Error

The associated error which can be returned from parsing.

fn from_str(string: &str) -> Result<Self>

Parses a string s to return a value of this type.

impl Hash for Eof

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for Eof

fn cmp(&self, other: &Eof) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl Parse for Eof

fn parse(input: ParseStream<'_>) -> Result<Self>

impl PartialEq for Eof

fn eq(&self, other: &Eof) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Eof

fn partial_cmp(&self, other: &Eof) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl ToTokens for Eof

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

Write self to the given TokenStream.

fn to_token_stream(&self) -> TokenStream

Convert self directly into a TokenStream object.

fn into_token_stream(self) -> TokenStream

where Self: Sized,

Convert self directly into a TokenStream object.

impl Copy for Eof

impl Eq for Eof

impl StructuralPartialEq for Eof