use rustyline

Cargo.lock

@@ -69,9 +69,15 @@ checksum = "349f9b6a179ed607305526ca489b34ad0a41aed5f7980fa90eb03160b69598fb"
 
 [[package]]
 name = "bitflags"
-version = "1.3.2"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+checksum = "cf1de2fe8c75bc145a2f577add951f8134889b4795d47466a54a5c846d691693"
+
+[[package]]
+name = "cc"
+version = "1.0.71"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "79c2681d6594606957bbb8631c4b90a7fcaaa72cdb714743a437b156d6a7eedd"
 
 [[package]]
 name = "cfg-if"
@@ -79,6 +85,17 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "clipboard-win"
+version = "4.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3db8340083d28acb43451166543b98c838299b7e0863621be53a338adceea0ed"
+dependencies = [
+ "error-code",
+ "str-buf",
+ "winapi",
+]
+
 [[package]]
 name = "crunchy"
 version = "0.2.2"
@@ -137,6 +154,33 @@ dependencies = [
  "log",
 ]
 
+[[package]]
+name = "endian-type"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c34f04666d835ff5d62e058c3995147c06f42fe86ff053337632bca83e42702d"
+
+[[package]]
+name = "error-code"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5115567ac25674e0043e472be13d14e537f37ea8aa4bdc4aef0c89add1db1ff"
+dependencies = [
+ "libc",
+ "str-buf",
+]
+
+[[package]]
+name = "fd-lock"
+version = "3.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8806dd91a06a7a403a8e596f9bfbfb34e469efbc363fc9c9713e79e26472e36"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "winapi",
+]
+
 [[package]]
 name = "fixedbitset"
 version = "0.2.0"
@@ -299,6 +343,7 @@ dependencies = [
  "pretty_assertions",
  "rand",
  "regex",
+ "rustyline",
 ]
 
 [[package]]
@@ -307,12 +352,43 @@ version = "2.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
 
+[[package]]
+name = "memoffset"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59accc507f1338036a0477ef61afdae33cde60840f4dfe481319ce3ad116ddf9"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "new_debug_unreachable"
 version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e4a24736216ec316047a1fc4252e27dabb04218aa4a3f37c6e7ddbf1f9782b54"
 
+[[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 = "0.22.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d3bb9a13fa32bc5aeb64150cd3f32d6cf4c748f8f8a417cce5d2eb976a8370ba"
+dependencies = [
+ "bitflags",
+ "cc",
+ "cfg-if",
+ "libc",
+ "memoffset",
+]
+
 [[package]]
 name = "output_vt100"
 version = "0.1.2"
@@ -414,6 +490,16 @@ 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 = "rand"
 version = "0.8.4"
@@ -496,6 +582,30 @@ version = "1.0.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61b3909d758bb75c79f23d4736fac9433868679d3ad2ea7a61e3c25cfda9a088"
 
+[[package]]
+name = "rustyline"
+version = "9.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "790487c3881a63489ae77126f57048b42d62d3b2bafbf37453ea19eedb6340d6"
+dependencies = [
+ "bitflags",
+ "cfg-if",
+ "clipboard-win",
+ "dirs-next",
+ "fd-lock",
+ "libc",
+ "log",
+ "memchr",
+ "nix",
+ "radix_trie",
+ "scopeguard",
+ "smallvec",
+ "unicode-segmentation",
+ "unicode-width",
+ "utf8parse",
+ "winapi",
+]
+
 [[package]]
 name = "scopeguard"
 version = "1.1.0"
@@ -514,6 +624,12 @@ version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ecab6c735a6bb4139c0caafd0cc3635748bbb3acf4550e8138122099251f309"
 
+[[package]]
+name = "str-buf"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d44a3643b4ff9caf57abcee9c2c621d6c03d9135e0d8b589bd9afb5992cb176a"
+
 [[package]]
 name = "string_cache"
 version = "0.8.2"
@@ -558,6 +674,18 @@ dependencies = [
  "crunchy",
 ]
 
+[[package]]
+name = "unicode-segmentation"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8895849a949e7845e06bd6dc1aa51731a103c42707010a5b591c0038fb73385b"
+
+[[package]]
+name = "unicode-width"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ed742d4ea2bd1176e236172c8429aaf54486e7ac098db29ffe6529e0ce50973"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
@@ -570,6 +698,12 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b4ae116fef2b7fea257ed6440d3cfcff7f190865f170cdad00bb6465bf18ecba"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "936e4b492acfd135421d8dca4b1aa80a7bfc26e702ef3af710e0752684df5372"
+
 [[package]]
 name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"

Cargo.toml

@@ -23,6 +23,7 @@ regex = "1"
 rand = "*"
 lalrpop-util = { version = "*", features = ["lexer"] }
 logos = "*"
+rustyline = "*"
 
 [build-dependencies.lalrpop]
 version = "*"

src/grammar.lalrpop

@@ -1,4 +1,3 @@
-use std::str::FromStr;
 use crate::ast::*;
 use crate::lexer::*;
 

src/main.rs

@@ -1,9 +1,6 @@
 use matzo::grammar::StmtsParser;
 use matzo::interp::State;
 use matzo::lexer::tokens;
-use logos::Logos;
-
-use std::io::Write;
 
 fn run(src: &str) {
     let lexed = tokens(&src);
@@ -16,19 +13,22 @@ fn run(src: &str) {
     }
 }
 
-fn run_repl() -> std::io::Result<()> {
+fn run_repl() -> Result<(), Box<dyn std::error::Error>> {
+    let mut rl = rustyline::Editor::<()>::new();
     let mut state = State::new();
     let parser = StmtsParser::new();
-    let mut stdout = std::io::stdout();
-    let stdin = std::io::stdin();
-    let mut buf = String::new();
+    println!("matzo interpreter");
+    println!("(work-in-progress)");
 
     loop {
-        stdout.write(b">>> ")?;
-        stdout.flush()?;
-        buf.clear();
-        stdin.read_line(&mut buf)?;
-        let lexed = tokens(&buf);
+        let line = match rl.readline(">>> ") {
+            Ok(ln) => ln,
+            Err(rustyline::error::ReadlineError::Eof) |
+            Err(rustyline::error::ReadlineError::Interrupted) =>
+                return Ok(()),
+            err => err?,
+        };
+        let lexed = tokens(&line);
 
         let stmts = match parser.parse(lexed) {
             Ok(stmts) => stmts,