gnark should be able to export a Solidity verifier

[gbotrel]

All needed informations should be in the VerifyingKey data structure.

The export / convert function takes as input the VerifyingKey and a io.Writer . Writes on the io.Writer a solidity smart contract that takes as input a proof and a set of public inputs (as defined in the VerifyingKey).

Low priority task.

[weijiekoh]

I'd suggest using the verifier code here as is has been audited: https://github.com/appliedzkp/semaphore/blob/master/contracts/sol/verifier.sol

Audit report: https://github.com/appliedzkp/semaphore/blob/master/audit/Audit%20Report%20Summary%20for%20Semaphore%20and%20MicroMix.pdf