Crate pounce_nl 

AMPL .nl reader, reverse-mode AD tape, and TNLP evaluator.

This crate holds the .nl pipeline that used to live in pounce-cli:

• nl_reader parses a .nl file into an nl_reader::NlProblem (the Expr DAG, linear parts, bounds, names, starting point) and provides nl_reader::NlTnlp, a pounce_nlp::tnlp::TNLP implementation that evaluates objective/gradient/Hessian and constraints/Jacobian.
• nl_tape flattens an Expr DAG into a reverse-mode AD tape with colored forward-over-reverse Hessian products.
• nl_external supports AMPL imported (external) functions via the funcadd_ASL ABI.
• nl_fbbt_translate lowers an Expr to an FbbtTape for feasibility-based bound tightening.

It is a leaf crate (depends only on pounce-common and pounce-nlp) so both the CLI and the Python bindings can read and evaluate .nl models without depending on each other.

Modules

nl_external

AMPL imported (external) function support via the funcadd_ASL ABI.

nl_fbbt_translate

Translate parsed .nl constraint expressions into an FbbtTape for the presolve FBBT pass (issue #62).

nl_reader

Minimal AMPL .nl ASCII-format reader.

nl_tape

Flat-tape reverse-mode AD for .nl expression trees.