Combine the error types.

src/compare/sexp.rs

@@ -1,3 +1,6 @@
+use crate::error::CustomError;
+use crate::error::MyError;
+use crate::error::Res;
 use std::collections::HashMap;
 
 use nom::branch::alt;
@@ -16,8 +19,6 @@ use nom::sequence::delimited;
 use nom::sequence::preceded;
 use nom::sequence::tuple;
 
-use super::error::Res;
-
 #[derive(Debug)]
 pub enum Token<'s> {
     Atom(&'s str),