From 7e0195b0a753bd990307587926bfc0fe11927f77 Mon Sep 17 00:00:00 2001
From: franck cuny <franck@fcuny.net>
Date: Sat, 11 Jan 2020 14:50:44 +0100
Subject: repl: support a simple REPL for some early testing

The REPL reads the input, send it to the lexer, and prints the token to
STDOUT. For now nothing else is done since we still don't parse the
tokens.
---
 users/fcuny/exp/monkey/cmd/repl/main.go | 12 ++++++++++++
 users/fcuny/exp/monkey/pkg/repl/repl.go | 29 +++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 users/fcuny/exp/monkey/cmd/repl/main.go
 create mode 100644 users/fcuny/exp/monkey/pkg/repl/repl.go

diff --git a/users/fcuny/exp/monkey/cmd/repl/main.go b/users/fcuny/exp/monkey/cmd/repl/main.go
new file mode 100644
index 0000000..46b865c
--- /dev/null
+++ b/users/fcuny/exp/monkey/cmd/repl/main.go
@@ -0,0 +1,12 @@
+package main
+
+import (
+	"fmt"
+	"monkey/pkg/repl"
+	"os"
+)
+
+func main() {
+	fmt.Printf("Welcome to monkey's REPL.")
+	repl.Start(os.Stdin, os.Stdout)
+}
diff --git a/users/fcuny/exp/monkey/pkg/repl/repl.go b/users/fcuny/exp/monkey/pkg/repl/repl.go
new file mode 100644
index 0000000..e8b3b1f
--- /dev/null
+++ b/users/fcuny/exp/monkey/pkg/repl/repl.go
@@ -0,0 +1,29 @@
+package repl
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	lexer "monkey/pkg/lexer"
+	token "monkey/pkg/token"
+)
+
+const PROMPT = ">> "
+
+func Start(in io.Reader, out io.Writer) {
+	scanner := bufio.NewScanner(in)
+	for {
+		fmt.Printf(PROMPT)
+		scanned := scanner.Scan()
+
+		if !scanned {
+			return
+		}
+
+		line := scanner.Text()
+		l := lexer.New(line)
+		for tok := l.NextToken(); tok.Type != token.EOF; tok = l.NextToken() {
+			fmt.Printf("%+v\n", tok)
+		}
+	}
+}
-- 
cgit 1.4.1