Struct syn::LitStr

pub struct LitStr { /* fields omitted */ }

A UTF-8 string literal: "foo".

This type is available if Syn is built with the "derive" or "full" feature.

Methods

impl LitStr

pub fn new(value: &str, span: Span) -> Self

pub fn value(&self) -> String

pub fn parse<T: Parse>(&self) -> Result<T>

Parse a syntax tree node from the content of this string literal.

All spans in the syntax tree will point to the span of this LitStr.

Example

use proc_macro2::Span;
use syn::{Attribute, Error, Ident, Lit, Meta, MetaNameValue, Path, Result};

// Parses the path from an attribute that looks like:
//
//     #[path = "a::b::c"]
//
// or returns `None` if the input is some other attribute.
fn get_path(attr: &Attribute) -> Result<Option<Path>> {
    if !attr.path.is_ident("path") {
        return Ok(None);
    }

    match attr.parse_meta()? {
        Meta::NameValue(MetaNameValue { lit: Lit::Str(lit_str), .. }) => {
            lit_str.parse().map(Some)
        }
        _ => {
            let message = "expected #[path = \"...\"]";
            Err(Error::new_spanned(attr, message))
        }
    }
}

pub fn parse_with<F: Parser>(&self, parser: F) -> Result<F::Output>

Invoke parser on the content of this string literal.

All spans in the syntax tree will point to the span of this LitStr.

Example

# use proc_macro2::Span;
# use syn::{LitStr, Result};
#
# fn main() -> Result<()> {
#     let lit_str = LitStr::new("a::b::c", Span::call_site());
#
#     const IGNORE: &str = stringify! {
let lit_str: LitStr = /* ... */;
#     };

// Parse a string literal like "a::b::c" into a Path, not allowing
// generic arguments on any of the path segments.
let basic_path = lit_str.parse_with(syn::Path::parse_mod_style)?;
#
#     Ok(())
# }

pub fn span(&self) -> Span

pub fn set_span(&mut self, span: Span)

Trait Implementations

impl Token for LitStr

fn peek(cursor: Cursor) -> bool

fn display() -> &'static str

impl Parse for LitStr

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

impl PartialEq<LitStr> for LitStr

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

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

#[must_use]

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

This method tests for !=.

impl Clone for LitStr

fn clone(&self) -> LitStr

Returns a copy of the value.

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

Performs copy-assignment from source.

impl From<LitStr> for Lit

fn from(e: LitStr) -> Lit

Performs the conversion.

impl Eq for LitStr

impl Debug for LitStr

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

Formats the value using the given formatter.

impl Hash for LitStr

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

Feeds this value into the given [Hasher].

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

Feeds a slice of this type into the given [Hasher].

impl ToTokens for LitStr

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

Write self to the given TokenStream.

fn into_token_stream(self) -> TokenStream

Convert self directly into a TokenStream object.