feat(lineedit): add very basic readline

Cargo.lock

@@ -84,6 +84,14 @@ checksum = "18a6dbe30758c9f83eb00cbea4ac95966305f5a7772f3f42ebfc7fc7eddbd8e1"
 [[package]]
 name = "oyster"
 version = "0.1.0"
+dependencies = [
+ "oyster_lineedit",
+ "oyster_parser",
+]
+
+[[package]]
+name = "oyster_lineedit"
+version = "0.0.0"
 
 [[package]]
 name = "oyster_parser"

crates/oyster/Cargo.toml

@@ -4,3 +4,5 @@ version = "0.1.0"
 edition = "2021"
 
 [dependencies]
+oyster_lineedit = { path = "../oyster_lineedit" }
+oyster_parser = { path = "../oyster_parser" }

crates/oyster/src/main.rs

@@ -1,3 +1,14 @@
+use oyster_lineedit::readline;
+use oyster_parser::ast::Code;
+
 fn main() {
-    println!("Hello, world!");
+    loop {
+        let prog = readline("> ").unwrap();
+
+        if prog.trim() == "exit" {
+            break;
+        }
+
+        Code::try_from(prog.as_ref()).unwrap();
+    }
 }

crates/oyster_lineedit/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "oyster_lineedit"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+doctest = false

crates/oyster_lineedit/src/lib.rs

@@ -0,0 +1,11 @@
+use std::io::{self, Write};
+
+pub fn readline(prompt: &str) -> Result<String, io::Error> {
+    print!("{}", prompt);
+    io::stdout().flush()?;
+
+    let mut buf = String::new();
+    io::stdin().read_line(&mut buf)?;
+
+    Ok(buf)
+}