Add regex crate.

Cargo.lock

@@ -30,9 +30,19 @@ dependencies = [
  "itertools",
  "pathfinding",
  "rand",
+ "regex",
  "ureq",
 ]
 
+[[package]]
+name = "aho-corasick"
+version = "0.7.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4f55bd91a0978cbfd91c457a164bab8b4001c833b7f323132c0a4e1922dd44e"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "askama"
 version = "0.11.1"
@@ -720,6 +730,23 @@ dependencies = [
  "bitflags",
 ]
 
+[[package]]
+name = "regex"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c4eb3267174b8c6c2f654116623910a0fef09c4753f8dd83db29c48a0df988b"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.27"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a3f87b73ce11b1619a3c6332f45341e0047173771e8b8b73f87bfeefb7b56244"
+
 [[package]]
 name = "remove_dir_all"
 version = "0.5.3"

Cargo.toml

@@ -24,4 +24,5 @@ emojis = "0.4.0"
 itertools = "0.10.5"
 pathfinding = "3.0.13"
 rand = "0.8.5"
+regex = "1.6.0"
 ureq = { version = "2.5.0", features = ["cookie", "cookie_store"] }

source/prelude.rs

@@ -12,6 +12,7 @@ pub use {
   },
   itertools::Itertools,
   pathfinding::prelude::astar,
+  regex::Regex,
 };
 
 pub use crate::solution::{Day, Solution};