Qeustion about Ftreesit_pattern_expand

[Gerd Möllmann]

Not important, just as context: I wanted to see if igc works with
treesit Lisp objects, built with treesitter, and finally even got
grammars for C and C++ installed :-/. Font-locking didn't work in my
fork (CL packages), which I fixed.

My question:

Function Ftreesit_pattern_expand uses this to print Lisp objects:

  return Fprin1_to_string (pattern, Qnil, Qt);

where prin1 prints readably, and second arg nil means add escapes as
needed to that the result can be read back, by function read.

Why is it printing readably with escapes?

I know tree-sitter doesn't understand Lisp escaping because that was my
problem with the font-locking. Or, in other words, should the second arg
be Qt for don't escape?