Is there a way to run the script as if it were typed into the interpeter? The benefits are that I don't need echos everywhere, the work done is saved as a file, and I can use vim to do the editing. Example:
example.ijs
x =. 1
x + 3
terminal
x =. 1
x + 3
4
If not, I'll write a vimscript that can do the above then share them here. The advantage of a vimscript solution is that I could have commands to run the entire file, the current line, the current selection, everything up to and including the current line, or whatever else is useful.
Related but not a duplicate: How to call J (ijconsole) with a script automatically
Use loadd rather than load to run the script and display the lines and results.
loadd 'example.ijs'
x =. 1
x + 3
4