0.3.3

This update features contributions from participants in unitaryHACK 2023:

• Two new optimisers:
  • The Nelder-Mead optimiser. (credit: Gopal Dahale)
  • The Rotosolve optimiser. (credit: Ahmed Darwish)
• A new rewrite rule for handling unknown words. (credit: WingCode)

Many thanks to all who participated.

This update also contains the following changes:

Added:

• DiagramRewriter is a new class that rewrites diagrams by looking at the diagram as a whole rather than by using rewrite rules on individual boxes. This includes an example UnifyCodomainRewriter which adds an extra box to the end of diagrams to change the output to a specified type. (credit: A.C.E07)
• Added an early stopping mechanism to Trainer using the parameter early_stopping_interval.

Fixed:

• In PennyLaneModel, SymPy symbols are now substituted during the forward pass so that gradients are back-propagated to the original parameters.
• A pickling error that prevented CCG trees produced by BobcatParser from being unpickled has been fixed.