Not in the TXR pattern language, I&#x27;m afraid! TXR Lisp has those interactive properties of just re-loading a module on-the-fly to redefine some functions without redefining the entire program, but the pattern language isn&#x27;t interactive in that way.<p>This is from the ground up, pretty much, emanating from the way it is parsed in its entirety before being executed.<p>You can develop the logic in small pieces and test them in isolation on some sub-segment of the data, then integrate the pieces into a larger script with @(load ...).<p>Speaking of code refactorings, I also use it for that myself. When using it to interactively rewrite code, I invoke it in a pipeline out of vim. E.g. select some range of code visually with V, then &quot;!txr script.txr -[Enter]&quot; to filter it through. Vim deletes the original text and replaces it with the output. If the output is wrong, I hit u for undo to restore the original text. Then of course I have to fix script.txr and save it, and recall and repeat that filtering step just with &quot;:[up arrow][Enter]&quot;.<p>To avoid refreshing the output file during development, don&#x27;t have one; let it dump to standard output.<p>Something useful is that we can also monitor the first N lines of an output file that fit into the screen using the watch utility that is found in many GNU&#x2F;Linux distros. Watch repeatedly executes some command that is given (once every 2.0 seconds by default) and splashes its output on a clear screen. If we &quot;watch cat file&quot;, we can monitor the changing contents of file.