Keep rule order in `abnf_to_pest`

Closes #79

3 files changed, 10 insertions, 2 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 2436740..9f52ce3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -13,6 +13,7 @@ name = "abnf_to_pest"
 version = "0.1.0"
 dependencies = [
  "abnf 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pretty 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -150,6 +151,11 @@ name = "improved_slice_patterns"
 version = "1.0.1"
 
 [[package]]
+name = "indexmap"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "itertools"
 version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -419,6 +425,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum fake-simd 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e88a8acf291dafb59c2d96e8f59828f3838bb1a70398823ade51a84de6a6deed"
 "checksum generic-array 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ef25c5683767570c2bbd7deba372926a55eaae9982d7726ee2a1050239d45b9d"
 "checksum half 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "9353c2a89d550b58fa0061d8ed8d002a7d8cdf2494eb0e432859bd3a9e543836"
+"checksum indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7e81a7c05f79578dbc15793d8b619db9ba32b4577003ef3af1a91c416798c58d"
 "checksum itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b8467d9c1cebe26feb08c640139247fac215782d35371ade9a2136ed6085358"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08cbb6b4fef96b6d77bfc40ec491b1690c779e77b05cd9f07f787ed376fd4c43"
diff --git a/abnf_to_pest/Cargo.toml b/abnf_to_pest/Cargo.toml
index fc9fe66..cd6aa10 100644
--- a/abnf_to_pest/Cargo.toml
+++ b/abnf_to_pest/Cargo.toml
@@ -10,5 +10,6 @@ doctest = false
 
 [dependencies]
 abnf = "0.1.2"
+indexmap = "1.0.2"
 itertools = "0.8.0"
 pretty = "0.5.2"
diff --git a/abnf_to_pest/src/lib.rs b/abnf_to_pest/src/lib.rs
index 46bd79d..f1a167f 100644
--- a/abnf_to_pest/src/lib.rs
+++ b/abnf_to_pest/src/lib.rs
@@ -8,7 +8,7 @@ pub use abnf::abnf::{
 };
 use itertools::Itertools;
 use pretty::{BoxDoc, Doc};
-use std::collections::HashMap;
+use indexmap::map::IndexMap;
 
 trait Pretty {
     fn pretty(&self) -> Doc<'static, BoxDoc<'static, ()>>;
@@ -146,7 +146,7 @@ impl Pretty for (String, PestyRule) {
 /// Parse an abnf file. Returns a map of rules.
 pub fn parse_abnf(
     data: &[u8],
-) -> Result<HashMap<String, PestyRule>, std::io::Error> {
+) -> Result<IndexMap<String, PestyRule>, std::io::Error> {
     let make_err =
         |e| std::io::Error::new(std::io::ErrorKind::Other, format!("{}", e));
     let rules: Vec<Rule> =