more useful parse errors

parse.cm

@@ -1196,6 +1196,36 @@ var parse = function(tokens, src, filename, tokenizer) {
     }
 
     if (k == "name") {
+      if (tok.value == "try" || tok.value == "catch" || tok.value == "finally") {
+        parse_error(start, "'" + tok.value + "' is not supported; use disrupt/disruption instead")
+        sync_to_statement()
+        return null
+      }
+      if (tok.value == "throw") {
+        parse_error(start, "'throw' is not supported; use disrupt instead")
+        sync_to_statement()
+        return null
+      }
+      if (tok.value == "class") {
+        parse_error(start, "'class' is not supported; use meme()/proto() instead")
+        sync_to_statement()
+        return null
+      }
+      if (tok.value == "new") {
+        parse_error(start, "'new' is not supported; use meme()/proto() instead")
+        sync_to_statement()
+        return null
+      }
+      if (tok.value == "switch" || tok.value == "case") {
+        parse_error(start, "'" + tok.value + "' is not supported; use if/else instead")
+        sync_to_statement()
+        return null
+      }
+      if (tok.value == "let" || tok.value == "const") {
+        parse_error(start, "'" + tok.value + "' is not supported; use var/def instead")
+        sync_to_statement()
+        return null
+      }
       p1_tok = peek_ahead(1)
       if (p1_tok.kind == ":") {
         node = ast_node("label", start)