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#![feature(proc_macro)]
extern crate rust_decimal;
extern crate proc_macro;
#[macro_use]
extern crate quote;

use proc_macro::TokenStream;
use rust_decimal::Decimal;
use std::str::FromStr;

#[proc_macro]
pub fn dec(input: TokenStream) -> TokenStream {
    let mut source = input.to_string();

    // If it starts with `- ` then get rid of the extra space
    // to_string will put a space between tokens
    if source.starts_with("- ") {
        source.remove(1);
    }
    
    let decimal = match Decimal::from_str(&source[..]) {
        Ok(d) => d,
        Err(e) => panic!("Unexpected decimal format for {}: {}", source, e),
    };

    let bytes = decimal.serialize();
    quote!(::rust_decimal::Decimal::deserialize(#bytes)).parse().unwrap()
}