Add helper script to generate the code

Makefile

@@ -2,6 +2,4 @@ build:
 	cargo build
 
 gen:
-	cat /dev/null > $(PWD)/src/rfc2865.rs
+	bash ./scripts/generate_code.sh
-	cargo run --bin code_gen $(PWD)/dicts/dictionary.rfc2865 $(PWD)/src/rfc2865.rs
-	cargo fmt

scripts/generate_code.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+set -eu
+
+REPO_ROOT="$(cd ./"$(git rev-parse --show-cdup)" || exit; pwd)"
+
+DICT_NAMES=(
+  "rfc2865"
+)
+
+for DICT_NAME in "${DICT_NAMES[@]}"; do
+  cat /dev/null > "${REPO_ROOT}/src/${DICT_NAME}.rs"
+  cargo run --bin code_gen "${REPO_ROOT}/dicts/dictionary.${DICT_NAME}" "${REPO_ROOT}/src/${DICT_NAME}.rs"
+done
+
+cargo fmt
+