[Adobe-source-devel] Questions about conditional_indirect_contributing_m

[cee1 <fy...@gm...>]

Hi all,
I'm reading the code of asl 1.0.42.
Some questions about *conditional_indirect_contributing_m*:
I found "*conditional_indirect_contributing_m*" (data member of
sheet_t::implementation_t) is *only set* in function
sheet_t::implementation_t::update:
(adam.cpp, 1119) accumulate_contributing_m.reset ();
...
(adam.cpp, 1143) conditional_indirect_contributing_m
= accumulate_contributing_m;

It seems conditional_indirect_contributing_m will always be zero, and is
referenced as "a_variable |= conditional_indirect_contributing_m", should it
be useless? What is conditional_indirect_contributing_m doing?

BTW, I've read the introduction at http://stlab.adobe.com and the paper
"Property Models -- From Incidental Algorithms to Reusable Components", I'm
still confused about:

   - What is the difference between output and interface cells?
   - Data flow of various cells? (e.g. data from input cell only flow to
   output|interface cell? output|interface cell only accept data from input
   cell?)
   - What is the difference between input and interface cells(e.g. why input
   cell setting init_contributing_m while interface cell(input) setting
   contributing_m)?
   - Are relation cells only involved in "getting" value of interface cells
   (output)?
   - What is invariant cell doing? If an invariant cell evaluated "false",
   all cells contributing to it will be marked poison?


Regards
-- cee1