combine common implementation of LC helpers (#4542)

* combine common implementation of LC helpers

Combine replicated helper code from Altair/Capella/EIP4844 into single
`Forky` based implementation. Also convert `template` to `func` to avoid
selection of incorrect overload.

* fix

beacon_chain/spec/datatypes/altair.nim

@@ -743,71 +743,6 @@ chronicles.formatIt LightClientUpdate: shortLog(it)
 chronicles.formatIt LightClientFinalityUpdate: shortLog(it)
 chronicles.formatIt LightClientOptimisticUpdate: shortLog(it)
 
-template toFull*(
-    update: SomeLightClientUpdate): LightClientUpdate =
-  when update is LightClientUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toFinality*(
-    update: SomeLightClientUpdate): LightClientFinalityUpdate =
-  when update is LightClientFinalityUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toOptimistic*(
-    update: SomeLightClientUpdate): LightClientOptimisticUpdate =
-  when update is LightClientOptimisticUpdate:
-    update
-  else:
-    LightClientOptimisticUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-func matches*[A, B: SomeLightClientUpdate](a: A, b: B): bool =
-  if a.attested_header != b.attested_header:
-    return false
-  when a is SomeLightClientUpdateWithSyncCommittee and
-      b is SomeLightClientUpdateWithSyncCommittee:
-    if a.next_sync_committee != b.next_sync_committee:
-      return false
-    if a.next_sync_committee_branch != b.next_sync_committee_branch:
-      return false
-  when a is SomeLightClientUpdateWithFinality and
-      b is SomeLightClientUpdateWithFinality:
-    if a.finalized_header != b.finalized_header:
-      return false
-    if a.finality_branch != b.finality_branch:
-      return false
-  if a.sync_aggregate != b.sync_aggregate:
-    return false
-  if a.signature_slot != b.signature_slot:
-    return false
-  true
-
 func clear*(info: var EpochInfo) =
   info.validators.setLen(0)
   info.balances = UnslashedParticipatingBalances()

beacon_chain/spec/datatypes/capella.nim

@@ -640,71 +640,6 @@ chronicles.formatIt LightClientUpdate: shortLog(it)
 chronicles.formatIt LightClientFinalityUpdate: shortLog(it)
 chronicles.formatIt LightClientOptimisticUpdate: shortLog(it)
 
-template toFull*(
-    update: SomeLightClientUpdate): LightClientUpdate =
-  when update is LightClientUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toFinality*(
-    update: SomeLightClientUpdate): LightClientFinalityUpdate =
-  when update is LightClientFinalityUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toOptimistic*(
-    update: SomeLightClientUpdate): LightClientOptimisticUpdate =
-  when update is LightClientOptimisticUpdate:
-    update
-  else:
-    LightClientOptimisticUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-func matches*[A, B: SomeLightClientUpdate](a: A, b: B): bool =
-  if a.attested_header != b.attested_header:
-    return false
-  when a is SomeLightClientUpdateWithSyncCommittee and
-      b is SomeLightClientUpdateWithSyncCommittee:
-    if a.next_sync_committee != b.next_sync_committee:
-      return false
-    if a.next_sync_committee_branch != b.next_sync_committee_branch:
-      return false
-  when a is SomeLightClientUpdateWithFinality and
-      b is SomeLightClientUpdateWithFinality:
-    if a.finalized_header != b.finalized_header:
-      return false
-    if a.finality_branch != b.finality_branch:
-      return false
-  if a.sync_aggregate != b.sync_aggregate:
-    return false
-  if a.signature_slot != b.signature_slot:
-    return false
-  true
-
 # https://github.com/ethereum/consensus-specs/blob/v1.3.0-rc.1/specs/capella/light-client/fork.md#upgrade_lc_store_to_capella
 func upgrade_lc_store_to_capella*(
     pre: altair.LightClientStore): LightClientStore =

beacon_chain/spec/datatypes/eip4844.nim

@@ -653,71 +653,6 @@ chronicles.formatIt LightClientUpdate: shortLog(it)
 chronicles.formatIt LightClientFinalityUpdate: shortLog(it)
 chronicles.formatIt LightClientOptimisticUpdate: shortLog(it)
 
-template toFull*(
-    update: SomeLightClientUpdate): LightClientUpdate =
-  when update is LightClientUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toFinality*(
-    update: SomeLightClientUpdate): LightClientFinalityUpdate =
-  when update is LightClientFinalityUpdate:
-    update
-  elif update is SomeLightClientUpdateWithFinality:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      finalized_header: update.finalized_header,
-      finality_branch: update.finality_branch,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-  else:
-    LightClientFinalityUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-template toOptimistic*(
-    update: SomeLightClientUpdate): LightClientOptimisticUpdate =
-  when update is LightClientOptimisticUpdate:
-    update
-  else:
-    LightClientOptimisticUpdate(
-      attested_header: update.attested_header,
-      sync_aggregate: update.sync_aggregate,
-      signature_slot: update.signature_slot)
-
-func matches*[A, B: SomeLightClientUpdate](a: A, b: B): bool =
-  if a.attested_header != b.attested_header:
-    return false
-  when a is SomeLightClientUpdateWithSyncCommittee and
-      b is SomeLightClientUpdateWithSyncCommittee:
-    if a.next_sync_committee != b.next_sync_committee:
-      return false
-    if a.next_sync_committee_branch != b.next_sync_committee_branch:
-      return false
-  when a is SomeLightClientUpdateWithFinality and
-      b is SomeLightClientUpdateWithFinality:
-    if a.finalized_header != b.finalized_header:
-      return false
-    if a.finality_branch != b.finality_branch:
-      return false
-  if a.sync_aggregate != b.sync_aggregate:
-    return false
-  if a.signature_slot != b.signature_slot:
-    return false
-  true
-
 # https://github.com/ethereum/consensus-specs/blob/v1.3.0-rc.1/specs/eip4844/light-client/fork.md#upgrade_lc_store_to_eip4844
 func upgrade_lc_store_to_eip4844*(
     pre: capella.LightClientStore): LightClientStore =

beacon_chain/spec/forks_light_client.nim

@@ -461,7 +461,25 @@ template withForkyStore*(
     const lcDataFork {.inject, used.} = LightClientDataFork.None
     body
 
-template toFull*(
+func toFull*(
+    update: SomeForkyLightClientUpdate): auto =
+  type ResultType = typeof(update).kind.LightClientUpdate
+  when update is ForkyLightClientUpdate:
+    update
+  elif update is SomeForkyLightClientUpdateWithFinality:
+    ResultType(
+      attested_header: update.attested_header,
+      finalized_header: update.finalized_header,
+      finality_branch: update.finality_branch,
+      sync_aggregate: update.sync_aggregate,
+      signature_slot: update.signature_slot)
+  else:
+    ResultType(
+      attested_header: update.attested_header,
+      sync_aggregate: update.sync_aggregate,
+      signature_slot: update.signature_slot)
+
+func toFull*(
     update: SomeForkedLightClientUpdate): ForkedLightClientUpdate =
   when update is ForkyLightClientUpdate:
     update
@@ -475,7 +493,25 @@ template toFull*(
       else:
         default(ForkedLightClientUpdate)
 
-template toFinality*(
+func toFinality*(
+    update: SomeForkyLightClientUpdate): auto =
+  type ResultType = typeof(update).kind.LightClientFinalityUpdate
+  when update is ForkyLightClientFinalityUpdate:
+    update
+  elif update is SomeForkyLightClientUpdateWithFinality:
+    ResultType(
+      attested_header: update.attested_header,
+      finalized_header: update.finalized_header,
+      finality_branch: update.finality_branch,
+      sync_aggregate: update.sync_aggregate,
+      signature_slot: update.signature_slot)
+  else:
+    ResultType(
+      attested_header: update.attested_header,
+      sync_aggregate: update.sync_aggregate,
+      signature_slot: update.signature_slot)
+
+func toFinality*(
     update: SomeForkedLightClientUpdate): ForkedLightClientFinalityUpdate =
   when update is ForkyLightClientFinalityUpdate:
     update
@@ -489,7 +525,18 @@ template toFinality*(
       else:
         default(ForkedLightClientFinalityUpdate)
 
-template toOptimistic*(
+func toOptimistic*(
+    update: SomeForkyLightClientUpdate): auto =
+  type ResultType = typeof(update).kind.LightClientOptimisticUpdate
+  when update is ForkyLightClientOptimisticUpdate:
+    update
+  else:
+    ResultType(
+      attested_header: update.attested_header,
+      sync_aggregate: update.sync_aggregate,
+      signature_slot: update.signature_slot)
+
+func toOptimistic*(
     update: SomeForkedLightClientUpdate): ForkedLightClientOptimisticUpdate =
   when update is ForkyLightClientOptimisticUpdate:
     update
@@ -503,6 +550,28 @@ template toOptimistic*(
       else:
         default(ForkedLightClientOptimisticUpdate)
 
+func matches*[A, B: SomeForkyLightClientUpdate](a: A, b: B): bool =
+  static: doAssert typeof(A).kind == typeof(B).kind
+  if a.attested_header != b.attested_header:
+    return false
+  when a is SomeForkyLightClientUpdateWithSyncCommittee and
+      b is SomeForkyLightClientUpdateWithSyncCommittee:
+    if a.next_sync_committee != b.next_sync_committee:
+      return false
+    if a.next_sync_committee_branch != b.next_sync_committee_branch:
+      return false
+  when a is SomeForkyLightClientUpdateWithFinality and
+      b is SomeForkyLightClientUpdateWithFinality:
+    if a.finalized_header != b.finalized_header:
+      return false
+    if a.finality_branch != b.finality_branch:
+      return false
+  if a.sync_aggregate != b.sync_aggregate:
+    return false
+  if a.signature_slot != b.signature_slot:
+    return false
+  true
+
 func matches*[A, B: SomeForkedLightClientUpdate](a: A, b: B): bool =
   if a.kind != b.kind:
     return false