Cobble: Compiling Block Encodings for Quantum Computational Linear Algebra

This repository contains a research prototype implementation of the Cobble language from the paper "Cobble: Compiling Block Encodings for Quantum Computational Linear Algebra". This code is provided as-is to aid in reproducibility. It is not yet intended for production use, and a more complete reproduction package is under development.

Source organization

• src/cobble/expr.py — Expression AST: Basic, Const, Sum, Prod, Tensor, Poly, If, Division, Dagger, and the base Expr class. Expressions are built in Python and compiled to circuits.
• src/cobble/compile.py — Compilation from expressions to circuits (LCU, QSP, etc.).
• src/cobble/circuit.py — Circuit representation (gates, allocations, controlled operations).
• src/cobble/qasm.py — Export of circuits to OpenQASM.
• src/cobble/optimize.py — Expression-level optimization (normalization, fusion, rewriting).
• src/cobble/polynomial.py — Polynomial types used by Poly(expr, polynomial).
• src/cobble/qtype.py — Types for expressions (e.g. BitType, tensor types).
• src/cobble/simulator.py — Simulator for testing block encodings.
• examples/ — Example Cobble programs (paper benchmarks and small demos).
• main.py — Entry point: runs the paper examples, optional QASM generation and timing.

To Run

pip install -r requirements.txt
pip install -e .
pytest  # run unit tests
python3 -i main.py  # run paper examples and enter interpreter