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#![deny(clippy::all)]
#![deny(clippy::pedantic)]
#![deny(missing_docs)]
//! Utility macros that should be in std but is not.
use std::iter::repeat;
use proc_macro::TokenStream;
use quote::quote;
use syn::parse::Parse;
use syn::{parse_macro_input, LitChar, LitInt, Token};
/// Repeats a character N number of times resulting in a string literal.
///
/// # Arguments
/// Seperated by commas.
///
/// - The character to repeat
/// - Number of times to repeat it.
///
/// # Examples
/// ```
/// # use utility_macros::repeat_char;
///
/// let eight_o = repeat_char!('o', 8);
///
/// assert_eq!(eight_o, "oooooooo");
/// ```
#[proc_macro]
pub fn repeat_char(input: TokenStream) -> TokenStream
{
let RepeatCharMacroArgs { character, count } =
parse_macro_input!(input as RepeatCharMacroArgs);
let repeated = repeat(character.value()).take(count).collect::<String>();
quote! {
#repeated
}
.into()
}
struct RepeatCharMacroArgs
{
character: LitChar,
count: usize,
}
impl Parse for RepeatCharMacroArgs
{
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self>
{
let character = input.parse::<LitChar>()?;
input.parse::<Token![,]>()?;
let count = input.parse::<LitInt>()?.base10_parse::<usize>()?;
Ok(Self { character, count })
}
}
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