From 52e2801fd2709e03077acc1528121ad020d30638 Mon Sep 17 00:00:00 2001
From: Sameer Rahmani <lxsameer@gnu.org>
Date: Sun, 26 Jan 2020 11:36:38 +0000
Subject: [PATCH] nRepl functionality has been added

---
 README.md                             | 11 +++++++++++
 src/main/java/serene/simple/Main.java |  9 +++++++++
 2 files changed, 20 insertions(+)

diff --git a/README.md b/README.md
index 08191f3..d0be392 100644
--- a/README.md
+++ b/README.md
@@ -10,3 +10,14 @@ my [blog](https://lxsameer.com/).
 
 ## Repl
 in order to run the REPL, run `make repl`
+
+## nRepl
+Use `make nrepl` command to fire up a nRepl process and connect to it using `netcat` or something
+similar. If you're using Emacs, there is a `serene-mode` available that distributes as part of
+[FG42](https://gitlab.com/FG42/FG42/blob/master/lib/extensions/serene/serene-simple-mode.el).
+
+Serene's nRepl is super simple. It waits for a newline char and then evaluates the
+given input. It sends back the result of the evaluation in `<status-char><value>` format.
+`status-char` is either `0` or `1`. **Zero** means the evaluation was successful and the `value`
+is the result of evaluation while **one** means there was an error during the evaluation and
+the `value` is the traceback for the exception.
diff --git a/src/main/java/serene/simple/Main.java b/src/main/java/serene/simple/Main.java
index cdf0d3e..ccf4696 100644
--- a/src/main/java/serene/simple/Main.java
+++ b/src/main/java/serene/simple/Main.java
@@ -115,6 +115,13 @@ public class Main {
     }
   }
 
+  /**
+   * Serene's nRepl is super simple. It waits for a newline char and then evaluates the
+   * given input. It sends back the result of the evaluation in `<status-char><value>` format.
+   * `status-char` is either `0` or `1`. **Zero** means the evaluation was successful and the `value`
+   * is the result of evaluation while **one** means there was an error during the evaluation and
+   * the `value` is the traceback for the exception.
+  */
   public static void nrepl() throws IOException {
     RootScope rootScope = new RootScope();
     ServerSocket socket = new ServerSocket(Main.port);;
@@ -124,6 +131,8 @@ public class Main {
     System.out.println(
       String.format("nRepl has been started on tcp://%s:%s", Main.host, Main.port));
 
+    // NOTE: The nRepl server is too simple. It supports one connection at a time
+    // and will terminate when the client disconnects.
     try {
       Socket clientSocket = socket.accept();