skeleton implementation of validator

mysticeti.nim

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+import ./mysticeti/validator
+
+export validator.Validator
+export validator.ProposalStatus
+export validator.new
+export validator.nextRound
+export validator.propose
+export validator.receive
+export validator.status
+
+import ./mysticeti/transactions
+
+export transactions.Transaction
+export transactions.Block
+export transactions.round

mysticeti/basics.nim

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+import std/tables
+
+export tables
+
+import pkg/questionable
+import pkg/questionable/results
+
+export questionable
+export results

mysticeti/identity.nim

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+type Identity* = object
+type Identifier* = object
+
+func init*(_: type Identity): Identity =
+  Identity()
+
+func identifier*(identity: Identity): Identifier =
+  discard
+
+type Signed*[T] = object
+  value: T
+
+func sign*[T](identity: Identity, value: T): Signed[T] =
+  Signed[T](value: value)
+
+func value*[T](signed: Signed[T]): T =
+  signed.value
+
+func signatories*[T](signed: Signed[T]): seq[Identifier] =
+  discard

mysticeti/transactions.nim

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+import ./identity
+
+type Transaction* = object
+
+type
+  Block* = object
+    author: Identifier
+    round: uint64
+    parents: seq[BlockHash]
+    transactions: seq[Transaction]
+  BlockHash* = object
+
+func new*(
+  _: type Block,
+  author: Identifier,
+  round: uint64,
+  parents: seq[BlockHash],
+  transactions: seq[Transaction]
+): Block =
+  Block(
+    author: author,
+    round: round,
+    parents: parents,
+    transactions: transactions
+  )
+
+func author*(blck: Block): Identifier =
+  blck.author
+
+func round*(blck: Block): uint64 =
+  blck.round

mysticeti/validator.nim

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+import ./basics
+import ./identity
+import ./transactions
+
+type
+  Validator* = ref object
+    identity: Identity
+    round: Round
+  Round = ref object
+    number: uint64
+    previous: ?Round
+    proposals: Table[Identifier, seq[Proposal]]
+  Proposal = object
+    blck: Block
+    status: ProposalStatus
+  ProposalStatus* = enum
+    undecided
+    toSkip
+    toCommit
+
+func new*(_: type Validator): Validator =
+  Validator(identity: Identity.init(), round: Round(number: 0))
+
+func identifier*(validator: Validator): Identifier =
+  validator.identity.identifier
+
+func nextRound*(validator: Validator) =
+  let previous = validator.round
+  validator.round = Round(number: previous.number + 1, previous: some previous)
+
+func propose*(validator: Validator, transactions: seq[Transaction]): Signed[Block] =
+  var parents: seq[BlockHash]
+  let blck = Block.new(
+    author = validator.identifier,
+    round = validator.round.number,
+    parents = parents,
+    transactions = transactions
+  )
+  let proposal = Proposal(blck: blck)
+  validator.round.proposals[validator.identifier] = @[proposal]
+  validator.identity.sign(blck)
+
+func receive*(validator: Validator, proposal: Signed[Block]) =
+  discard
+
+func round(validator: Validator, number: uint64): ?Round =
+  var round = validator.round
+  while round.number > number and previous =? round.previous:
+    round = previous
+  if round.number == number:
+    some round
+  else:
+    none Round
+
+func status*(validator: Validator, blck: Block): ?ProposalStatus =
+  if round =? round(validator, blck.round) and blck.author in round.proposals:
+    let proposal = round.proposals[blck.author][0]
+    some proposal.status
+  else:
+    none ProposalStatus
+
+func status*(validator: Validator, proposal: Signed[Block]): ?ProposalStatus =
+  validator.status(proposal.value)

tests/examples.nim

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+import std/random
+import std/sequtils
+import mysticeti
+
+proc example*(_: type Transaction): Transaction =
+  discard
+
+proc example*[T](_: type seq[T], length=0..10): seq[T] =
+  newSeqWith(rand(length), T.example)

tests/nim.cfg

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+--path:".."

tests/testValidator.nim

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+import std/unittest
+import pkg/questionable
+import mysticeti
+import ./examples
+
+suite "Validator":
+
+  var validator: Validator
+  var validator2, validator3: Validator
+
+  setup:
+    validator = Validator.new()
+    validator2 = Validator.new()
+    validator3 = Validator.new()
+
+  test "by default proposals are undecided":
+    let proposal = validator.propose(seq[Transaction].example)
+    check validator.status(proposal) == some ProposalStatus.undecided