From 95fa527b433bf9e50e4bcd83171258506bf66d80 Mon Sep 17 00:00:00 2001
From: Jordan Orelli <jorelli@etsy.com>
Date: Fri, 14 Jun 2013 23:14:11 -0400
Subject: [PATCH] i put a tcp server in your lisp interpreter

---
 args.go  | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 skeam.go |  14 --------
 2 files changed, 101 insertions(+), 14 deletions(-)
 create mode 100644 args.go

diff --git a/args.go b/args.go
new file mode 100644
index 0000000..9417763
--- /dev/null
+++ b/args.go
@@ -0,0 +1,101 @@
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"net"
+	"os"
+)
+
+var tcpAddr = flag.String("tcp", "", "foo")
+
+func args() {
+	flag.Parse()
+	if *tcpAddr != "" {
+		runTCPServer()
+		return
+	}
+	filename := flag.Args()[1]
+	f, err := os.Open(filename)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "unable to read file ", filename)
+		os.Exit(1)
+	}
+	defer f.Close()
+
+	c := make(chan token, 32)
+	go lex(bufio.NewReader(f), c)
+	evalall(c, universe)
+}
+
+func printErrorMsg(message string) {
+	io.WriteString(os.Stderr, message)
+}
+
+func die(message string) {
+	printErrorMsg(message)
+	os.Exit(2)
+}
+
+func startConnection(conn net.Conn, c, d chan net.Conn) {
+	c <- conn
+	defer func() { d <- conn }()
+	disconnect := func() {
+		fmt.Println("disconnected")
+	}
+	r := bufio.NewReader(conn)
+	for {
+		if _, err := io.WriteString(conn, "> "); err != nil {
+			disconnect()
+			return
+		}
+		line, prefix, err := r.ReadLine()
+		if prefix {
+			fmt.Println("(prefix)")
+		}
+		switch err {
+		case nil:
+			break
+		case io.EOF:
+			disconnect()
+            return
+		default:
+			printErrorMsg(err.Error())
+			disconnect()
+            return
+		}
+
+		tokens := make(chan token, 32)
+		go lexs(string(line)+"\n", tokens)
+		evalall(tokens, universe)
+	}
+}
+
+func manageConnections(connect, disconnect chan net.Conn) {
+	for {
+		select {
+		case <-connect:
+
+		case <-disconnect:
+		}
+	}
+}
+
+func runTCPServer() {
+	connect, disconnect := make(chan net.Conn), make(chan net.Conn)
+	go manageConnections(connect, disconnect)
+	ln, err := net.Listen("tcp", *tcpAddr)
+	if err != nil {
+		die(err.Error())
+	}
+	for {
+		conn, err := ln.Accept()
+		if err != nil {
+			printErrorMsg(err.Error())
+			continue
+		}
+		go startConnection(conn, connect, disconnect)
+	}
+}
diff --git a/skeam.go b/skeam.go
index 68f029f..84eeda7 100644
--- a/skeam.go
+++ b/skeam.go
@@ -223,20 +223,6 @@ func evalall(c chan token, env *environment) {
 	}
 }
 
-func args() {
-	filename := os.Args[1]
-	f, err := os.Open(filename)
-	if err != nil {
-		fmt.Fprintln(os.Stderr, "unable to read file ", filename)
-		os.Exit(1)
-	}
-	defer f.Close()
-
-	c := make(chan token, 32)
-	go lex(bufio.NewReader(f), c)
-	evalall(c, universe)
-}
-
 func main() {
 	if DEBUG {
 		fmt.Println(universe)