I (partially) recreated your `seq 1 15` example here [1] -- no sleep, but my lshw wasn't as interesting as yours :-) I'm hitting command-shift-| to bring up the "filter through command" dialog.

[1]: https://tcj.io/i/textmate_piping.gif

i have not used textmate, but the description let me come up with this idea. maybe it's useful:

consider the command

A | B | C | D

when you process it in up, split the command at the | and process each one separately. that is first run

A;

save the output into a buffer (BA)

then pipe BA into B, save that into BB, and so on, until you have 4 buffers containing the outputs of A; A|B; A|B|C; and A|B|C|D;

now when the user edits, you can see which section is changed. say the user changes the command C into C1, so the pipeline becomes: A|B|C1|D

at this point you can pipe buffer BB (which has the output from A|B) into C1; write that into a new buffer BC1; and pipe that into D;

the old buffers C and D can be removed at this point, or you can keep them around in case the user undoes their change and goes back to an old version.

greetings, eMBee.