repline: Refactor for fewer redraws and more user control.

Definitely has bugs, but eh!

repline/examples/continue.rs

@@ -0,0 +1,42 @@
+//! Demonstrates the use of [read_and()]:
+//!
+//! The provided closure:
+//! 1. Takes a line of input (a [String])
+//! 2. Performs some calculation (using [FromStr])
+//! 3. Returns a [Result] containing a [Response] or an [Err]
+
+use repline::{error::Error as RlError, Repline, Response};
+use std::error::Error;
+
+fn main() -> Result<(), Box<dyn Error>> {
+    let mut rl = Repline::with_input(
+        "fn main {\r\n\tprintln(\"Foo!\")\r\n}\r\n".as_bytes(),
+        "\x1b[33m",
+        "  >",
+        " ?>",
+    );
+    while rl.read().is_ok() {}
+
+    let mut rl = rl.swap_input(std::io::stdin());
+    loop {
+        let f = |_line| -> Result<_, RlError> { Ok(Response::Continue) };
+        let line = match rl.read() {
+            Err(RlError::CtrlC(_)) => break,
+            Err(RlError::CtrlD(line)) => {
+                rl.deny();
+                line
+            }
+            Ok(line) => line,
+            Err(e) => Err(e)?,
+        };
+        print!("\x1b[G\x1b[J");
+        match f(&line) {
+            Ok(Response::Accept) => rl.accept(),
+            Ok(Response::Deny) => rl.deny(),
+            Ok(Response::Break) => break,
+            Ok(Response::Continue) => continue,
+            Err(e) => print!("\x1b[40G\x1b[A\x1bJ\x1b[91m{e}\x1b[0m\x1b[B"),
+        }
+    }
+    Ok(())
+}