From b3a9bca32dfb3536f6aad4b2baa7863b2d82cc40 Mon Sep 17 00:00:00 2001
From: Roman Godmaire <godmaire@twilit.io>
Date: Sun, 5 May 2024 08:36:57 -0400
Subject: [PATCH] feat: readline support in REPL

---
 Cargo.lock  | 245 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml  |   1 +
 src/main.rs |  43 +++++----
 3 files changed, 270 insertions(+), 19 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 9a454c7..94a6a4f 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -23,12 +23,66 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
 
+[[package]]
+name = "bitflags"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf4b9d6a944f767f8e5e0db018570623c85f3d925ac718db4e06d0187adb21c1"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
+[[package]]
+name = "clipboard-win"
+version = "5.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79f4473f5144e20d9aceaf2972478f06ddf687831eafeeb434fbaf0acc4144ad"
+dependencies = [
+ "error-code",
+]
+
+[[package]]
+name = "endian-type"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c34f04666d835ff5d62e058c3995147c06f42fe86ff053337632bca83e42702d"
+
+[[package]]
+name = "errno"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a258e46cdc063eb8519c00b9fc845fc47bcfca4130e2f08e88665ceda8474245"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
+[[package]]
+name = "error-code"
+version = "3.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a0474425d51df81997e2f90a21591180b38eccf27292d755f3e30750225c175b"
+
+[[package]]
+name = "fd-lock"
+version = "4.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e5768da2206272c81ef0b5e951a41862938a6070da63bcea197899942d3b947"
+dependencies = [
+ "cfg-if",
+ "rustix",
+ "windows-sys",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.28"
@@ -130,6 +184,33 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
 
+[[package]]
+name = "home"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3d1354bf6b7235cb4a0576c2619fd4ed18183f689b12b006a0ee7329eeff9a5"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.154"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae743338b92ff9146ce83992f766a31066a91a8c84a45e0e9f21e7cf6de6d346"
+
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "01cda141df6706de531b6c46c3a33ecca755538219bd484262fa09410c13539c"
+
+[[package]]
+name = "log"
+version = "0.4.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+
 [[package]]
 name = "memchr"
 version = "2.6.3"
@@ -142,9 +223,31 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "rstest",
+ "rustyline",
  "thiserror",
 ]
 
+[[package]]
+name = "nibble_vec"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77a5d83df9f36fe23f0c3648c6bbb8b0298bb5f1939c8f2704431371f4b84d43"
+dependencies = [
+ "smallvec",
+]
+
+[[package]]
+name = "nix"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "cfg_aliases",
+ "libc",
+]
+
 [[package]]
 name = "pin-project-lite"
 version = "0.2.13"
@@ -175,6 +278,16 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "radix_trie"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c069c179fcdc6a2fe24d8d18305cf085fdbd4f922c041943e203685d6a1c58fd"
+dependencies = [
+ "endian-type",
+ "nibble_vec",
+]
+
 [[package]]
 name = "regex"
 version = "1.9.5"
@@ -248,6 +361,41 @@ dependencies = [
  "semver",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.38.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
+dependencies = [
+ "bitflags",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys",
+]
+
+[[package]]
+name = "rustyline"
+version = "14.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7803e8936da37efd9b6d4478277f4b2b9bb5cdb37a113e8d63222e58da647e63"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "clipboard-win",
+ "fd-lock",
+ "home",
+ "libc",
+ "log",
+ "memchr",
+ "nix",
+ "radix_trie",
+ "unicode-segmentation",
+ "unicode-width",
+ "utf8parse",
+ "windows-sys",
+]
+
 [[package]]
 name = "semver"
 version = "1.0.18"
@@ -263,6 +411,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "smallvec"
+version = "1.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
+
 [[package]]
 name = "syn"
 version = "2.0.32"
@@ -299,3 +453,94 @@ name = "unicode-ident"
 version = "1.0.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+
+[[package]]
+name = "unicode-segmentation"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4c87d22b6e3f4a18d4d40ef354e97c90fcb14dd91d7dc0aa9d8a1172ebf7202"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68f5e5f3158ecfd4b8ff6fe086db7c8467a2dfdac97fe420f2b7c4aa97af66d6"
+
+[[package]]
+name = "utf8parse"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
+
+[[package]]
+name = "windows-sys"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+dependencies = [
+ "windows-targets",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_gnullvm",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88ba073cf16d5372720ec942a8ccbf61626074c6d4dd2e745299726ce8b89670"
+
+[[package]]
+name = "windows_i686_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.52.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bec47e5bfd1bff0eeaf6d8b485cc1074891a197ab4225d504cb7a1ab88b02bf0"
diff --git a/Cargo.toml b/Cargo.toml
index 688d590..2850d7d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.75"
+rustyline = "14.0.0"
 thiserror = "1.0.48"
 
 [dev-dependencies]
diff --git a/src/main.rs b/src/main.rs
index c503571..0117f01 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,4 +1,4 @@
-use std::io::{self, Write};
+use rustyline::{error::ReadlineError, DefaultEditor};
 
 mod env;
 mod error;
@@ -9,30 +9,35 @@ mod parser;
 
 fn main() {
     let env = env::Environment::new();
-    let mut input = String::new();
+    let mut rl = DefaultEditor::new().unwrap();
 
     println!("Mute -- REPL");
 
     loop {
-        print!("> ");
-        io::stdout().flush().expect("failed to write to stdout");
+        let readline = rl.readline("> ");
 
-        let bytes_read = io::stdin()
-            .read_line(&mut input)
-            .expect("failed to read from stdin");
+        match readline {
+            Ok(line) => {
+                rl.add_history_entry(line.as_str()).unwrap();
 
-        if bytes_read == 0 {
-            break;
+                let ast = parser::parse_str(&line).unwrap();
+                let res = evaluator::eval(&env, ast);
+
+                match res {
+                    Ok(expressions) => expressions.into_iter().for_each(|expr| println!("{expr}")),
+                    Err(err) => println!("{}", err),
+                }
+            }
+            Err(ReadlineError::Interrupted) => {
+                continue;
+            }
+            Err(ReadlineError::Eof) => {
+                break;
+            }
+            Err(err) => {
+                println!("Error: {:?}", err);
+                break;
+            }
         }
-
-        let ast = parser::parse_str(&input).unwrap();
-        let res = evaluator::eval(&env, ast);
-
-        match res {
-            Ok(expressions) => expressions.into_iter().for_each(|expr| println!("{expr}")),
-            Err(err) => println!("{}", err),
-        }
-
-        input.clear();
     }
 }