Enhance REPL user experience by adding Ctrl+L to clear the screen and improving Ctrl+C interruption handling

luash

@@ -213,7 +213,7 @@ function start_repl()
   -- Main REPL loop
   print("🚀 Luash Interactive Shell")
   print("Type Lua expressions, use $VAR for env vars, `commands` for shell")
-  print("Special commands: .help .exit .clear .history")
+  print("Special commands: .help .exit .clear .history  (Ctrl+L to clear, Ctrl+D to exit)")
   print("")
   
   while true do
@@ -221,13 +221,30 @@ function start_repl()
       io.write(prompt)
       io.flush()
       
-      local line = io.read("*line")
+      -- Safely read a line; handle Ctrl+C gracefully
+      local ok, line = pcall(io.read, "*line")
+      if not ok then
+          print("\nInterrupted (Ctrl+C)")
+          break
+      end
       
       if not line then -- EOF (Ctrl+D)
           print("\nGoodbye!")
           break
       end
       
+      -- Handle Ctrl+L (form feed) to clear screen
+      if line:find(string.char(12), 1, true) then
+          repl.buffer = ""
+          io.write("\27[2J\27[H") -- Clear screen and move cursor to top
+          io.flush()
+          print("🚀 Luash Interactive Shell")
+          print("Type Lua expressions, use $VAR for env vars, `commands` for shell")
+          print("Special commands: .help .exit .clear .history  (Ctrl+L to clear, Ctrl+D to exit)")
+          print("")
+          goto continue
+      end
+
       line = trim(line)
       
       -- Handle special dot commands
@@ -323,6 +340,7 @@ Multi-line input supported for functions, loops, etc.]])
               end
           end
       end
+      ::continue::
   end
 end
 
@@ -336,6 +354,7 @@ if filename == "-h" or filename == "--help" then
   return
 elseif not filename or filename == "-i" or filename == "--interactive" then
   start_repl()
+  return
 end
 
 local file = io.open(filename, "r")