First attempt at a simple repl

mithril.scm

@@ -36,3 +36,48 @@ Call: (mithril:comp ~s ~s)"
     :view
     (lambda (vnode) (,@view))
     ,@args))
+
+(define (mithril:repl prompt)
+  "(mithril:repl prompt preamble)
+
+Returns a REPL Mithril component that allows evaluating
+custom LIPS code. The environment used by this REPL is
+the same as the application execution environment, meaning
+that the DOM and running scripts can be modified.
+
+PROMPT specifies the user prompt."
+  (let* ((add-line (lambda (state text prompt?)
+		     (state.lines.push (list text prompt?))))
+	 (evaluate (lambda (state cmd)
+		     (add-line state (format "~a~a" prompt cmd) #t)
+		     (let ((res (eval str)))
+		       (when res
+			 (add-line state res #f)))))
+	 (handle-key-down (lambda (state e)
+			    (case e.key
+			      (("Enter")
+			       (e.preventDefault)
+			       (let ((cmd state.input))
+				 (set! state.input "")
+				 (evaluate state cmd)))))))
+    (mithril:comp
+     (let ((state vnode.state))
+       (sxml
+	(.repl
+	 (.repl-output
+	  ~(list->array
+	    (map
+	     (lambda (line)
+	       (m ".line" line.text))
+	     state.lines)))
+	 (.repl-input
+	  (span.prompt ~prompt)
+	  (input (@ (type "text")
+		    (value state.input)
+		    (oninput (lambda (e) (set! state.input e.target.value)))
+		    (onkeydown handle-key-down)
+		    (oncreate (lambda (vnode)
+				(set! state.inputRef vnode.dome)
+				(vnode.dom.focus)))
+		    (onfocus (lambda () (object)))
+		    (autofocus #t))))))))))