From 1b14ac40a6c792a23727fd0692e4f6cf97fc3fd7 Mon Sep 17 00:00:00 2001
From: Alex Shinn <ashinn@users.noreply.github.com>
Date: Tue, 13 Jul 2010 07:54:29 +0900
Subject: [PATCH] adding more featureful repl module

---
 lib/chibi/repl.module |  5 ++++
 lib/chibi/repl.scm    | 58 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+)
 create mode 100644 lib/chibi/repl.module
 create mode 100644 lib/chibi/repl.scm

diff --git a/lib/chibi/repl.module b/lib/chibi/repl.module
new file mode 100644
index 00000000..4db9a267
--- /dev/null
+++ b/lib/chibi/repl.module
@@ -0,0 +1,5 @@
+
+(define-module (chibi repl)
+  (export repl)
+  (import-immutable (scheme) (chibi process))
+  (include "repl.scm"))
diff --git a/lib/chibi/repl.scm b/lib/chibi/repl.scm
new file mode 100644
index 00000000..307b0253
--- /dev/null
+++ b/lib/chibi/repl.scm
@@ -0,0 +1,58 @@
+
+(define (run-repl module env)
+  (if module (display module))
+  (display "> ")
+  (flush-output)
+  (let lp ()
+    (let ((ch (peek-char)))
+      (cond ((eof-object? ch)
+             (exit 0))
+            ((and (char? ch) (char-whitespace? ch))
+             (read-char)
+             (lp)))))
+  (cond
+   ((eq? #\@ (peek-char))
+    (read-char)
+    (let ((sym (read)))
+      (if (not (symbol? sym))
+          (error "repl: invalid @ syntax: @" sym)
+          (case sym
+            ((config)
+             (let ((res (eval (read) *config-env*)))
+               (cond
+                ((not (eq? res (if #f #f)))
+                 (write res)
+                 (newline)))
+               (run-repl module env)))
+            ((in)
+             (let ((mod (read)))
+               (if (or (not mod) (equal? mod '(scheme)))
+                   (run-repl #f (interaction-environment))
+                   (let ((env (eval `(module-env (load-module ',mod))
+                                    *config-env*)))
+                     (run-repl mod env)))))
+            (else
+             (error "repl: unknown @ escape" sym))))))
+   (else
+    (let ((expr (read)))
+      (cond
+       ((eof-object? expr)
+        (exit 0))
+       (else
+        (let ((res (eval expr env)))
+          (cond
+           ((not (eq? res (if #f #f)))
+            (write res)
+            (newline)))
+          (run-repl module env))))))))
+
+(define (repl)
+  (set-signal-action! signal/interrupt
+                      (lambda (n info)
+                        (newline)
+                        (run-repl #f (interaction-environment))))
+  (current-exception-handler
+   (lambda (exn)
+     (print-exception exn (current-error-port))
+     (run-repl #f (interaction-environment))))
+  (run-repl #f (interaction-environment)))