You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: lib.rs
    path of file: ./repos/anchor/lang/syn/src
    
    the code of the file until where you have to start completion: #![cfg_attr(docsrs, feature(doc_auto_cfg))]

pub mod codegen;
pub mod parser;

#[cfg(feature = "idl-types")]
pub mod idl;

#[cfg(feature = "hash")]
pub mod hash;
#[cfg(not(feature = "hash"))]
pub(crate) mod hash;

use codegen::accounts as accounts_codegen;
use codegen::program as program_codegen;
use parser::accounts as accounts_parser;
use parser::program as program_parser;
use proc_macro2::{Span, TokenStream};
use quote::quote;
use quote::ToTokens;
use std::collections::HashMap;
use std::ops::Deref;
use syn::ext::IdentExt;
use syn::parse::{Error as ParseError, Parse, ParseStream, Result as ParseResult};
use syn::punctuated::Punctuated;
use syn::spanned::Spanned;
use syn::token::Comma;
use syn::{
    Ex
    
    pub fn account_ty(&self) -> proc_macro2::TokenStream {
        match &self.ty {
            Ty::AccountInfo => quote! {
                AccountInfo
            },
            Ty::UncheckedAccount => quote! {
                UncheckedAccount
            },
            Ty::Signer => quote! {
                Signer
            },
            Ty::SystemAccount => quote! {
                SystemAccount
            },
            Ty::ProgramData => quote! {
                ProgramData
            },
            Ty::Account(ty) => {
                let ident = &ty.account_type_path;
                quote! {
                    #ident
                }
            }
            Ty::InterfaceAccount(ty) => {
                let ident = &ty.account_type_path;
                quote! {
                    #ident
                }
            }
            Ty::AccountLoader(ty) => {
                let ident = &ty.account_type_path;
                quote! {
                    #ident
                }
            }
            Ty::Sysvar(ty) => match ty {
                SysvarTy::Clock => quote! {Clock},
                SysvarTy::Rent => quote! {Rent},
                SysvarTy::EpochSchedule => quote! {EpochSchedule},
                SysvarTy::Fees => quote! {Fees},
                SysvarTy::RecentBlockhashes => quote! {RecentBlockhashes},
                SysvarTy::SlotHashes => quote! {SlotHashes},
                SysvarTy::SlotHistory => quote! {SlotHistory},
                SysvarTy::StakeHistory => quote! {StakeHistory},
                SysvarTy::Instructions => quote! {Instructions},
                SysvarTy::Rewards => quote! {Rewards},
            },
            Ty::Program(ty) => {
                let program = &ty.account_type_path;
                quote! {
                    #program
                }
            }
            Ty::Interface(ty) => {
                let program = &ty.account_type_path;
                quote! {
                    #program
                }
            }
        }
    }