implement very primitive REPL

gem300.rkt

@@ -29,8 +29,8 @@
         (let ([header (read-line c-in 'return-linefeed)])
           (define-values (status meta)
             (let ([status-meta (string-split header " ")])
-              (values (list-ref status-meta 0)
-                      (list-ref status-meta 1))))
+              (values (car status-meta)
+                      (string-join (cdr status-meta)))))
 
           (cond
             [(> (string-length status) 2)
@@ -41,3 +41,27 @@
 
             [else
              (values (string->number status) meta)])))))
+
+(define commands
+  (list
+   (cons "default" (lambda (line) (void)))
+   (cons "go" (lambda (line)
+                (request line)))))
+
+(define (dispatch-command line)
+  (let ([split (string-split line " ")])
+
+    (let ([cmd (assoc (cond [(null? split) "default"]
+                            [else (first split)])
+                      commands)])
+      (if cmd
+          ((cdr cmd) (string-join (cdr split)))
+          (displayln "no such command")))))
+
+
+(define (repl)
+  (display "G300> ")
+  (dispatch-command (read-line))
+  (repl))
+
+(repl)