* Make Amount arithmetic more generic
To modify generated amounts, we need some extra operations on `Amount`.
We also need to extend existing operations to both `NonNegative` and
`NegativeAllowed` amounts.
* Add a constrain method for ValueBalance
* Derive Eq for ValueBalance
* impl Neg for ValueBalance
* Make some Amount arithmetic expectations explicit
* Explain why we use i128 for multiplication
And expand the overflow error details.
* Expand Amount::sum error details
* Make amount::Error field order consistent
* Rename an amount::Error variant to Constraint, so it's clearer
* Add specific pool variants to ValueBalanceError
* Update coinbase remaining value consensus rule comment
This consensus rule was updated recently to include coinbase transactions,
but Zebra doesn't check block subsidy or miner fees yet.
* Add test methods for modifying transparent values and shielded value balances
* Temporarily set values and value balances to zero in proptests
In both generated chains and proptests that construct their own transactions.
Using zero values reduces value calculation and value check test coverage.
A future change will use non-zero values, and fix them so the check passes.
* Add extra fields to remaining transaction value errors
* Swap the transparent value balance sign to match shielded value balances
This makes the signs of all the chain value pools consistent.
* Use a NonNegative constraint for transparent values
This fix:
* makes the type signature match the consensus rules
* avoids having to write code to handle negative values
* Allocate total generated transaction input value to outputs
If there isn't enough input value for an output, set it to zero.
Temporarily reduce all generated values to avoid overflow.
(We'll remove this workaround when we calculate chain value balances.)
* Consistently use ValueBalanceError for ValueBalances
* Make the value balance signs match the spec
And rename and document methods so their signs are clearer.
* Convert amount::Errors to specific pool ValueBalanceErrors
* Move some error changes to the next PR
* Add extra info to remaining transaction value errors (#2585)
* Distinguish between overflow and negative remaining transaction value errors
And make some error types cloneable.
* Add methods for updating chain value pools (#2586)
* Move amount::test to amount::tests:vectors
* Make ValueBalance traits more consistent with Amount
- implement Add and Sub variants with Result and Assign
- derive Hash
* Clarify some comments and expects
* Create ValueBalance update methods for blocks and transactions
Co-authored-by: Alfredo Garcia <oxarbitrage@gmail.com>