I'm trying to achieve something similar to etoolbox's \patchcmd.
Following some earlier discussion with Will,  I decided to try the
\tlp_replace_ ... functions.  However, trying a minimal example:

\def_new:NNn\macro 0 {TEXT}

I get an error about undefined \l_tlp_replace_toks.  I've not cut the
burning-edge of expl3, so this may have been fixed.  However, I thought
I should report it.
Joseph Wright          Tel.   01604 810094
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