finding indexed functions from pg_index

Hi,

I am trying to modify SQL::Translator, a perl module for translating
various dialects of SQL ddl (table, index creates, constraints, etc) (and
it does other cool things too, check it out!), to talk directly to a
PostgreSQL database to determine what tables it has, what columns they
have, indexes, constraints, etc. I have mostly figured out what I need
from pg_namespace, pg_class, pg_index and pg_attribute.

What I haven't figure out is this: how does one determine what the
declarative statement is for a functional index that is obtained from
pg_index.indexprs? What I would like to be able to do is be able to
recreate the SQL that defined that index. Is that represented somewhere
in another system table?

Thanks,
Scott

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Scott Cain, Ph. D. cain(at)cshl(dot)org
GMOD Coordinator, http://www.gmod.org/ (216)392-3087
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