change extensions to Pairs<Int, Data>

Author: Luivatra

aiken.lock

@@ -46,4 +46,4 @@ requirements = []
 source = "github"
 
 [etags]
-"aiken-lang/fuzz@main" = [{ secs_since_epoch = 1757410953, nanos_since_epoch = 792061707 }, "9843473958e51725a9274b487d2d4aac0395ec1a2e30f090724fa737226bc127"]
+"aiken-lang/fuzz@main" = [{ secs_since_epoch = 1758102049, nanos_since_epoch = 210673971 }, "9843473958e51725a9274b487d2d4aac0395ec1a2e30f090724fa737226bc127"]

lib/tests/examples/ex_settings.ak

@@ -31,10 +31,14 @@ pub fn mk_valid_settings_datum(scoopers: List<ByteArray>) -> SettingsDatum {
     simple_fee: 2_500_000,
     strategy_fee: 5_000_000,
     pool_creation_fee: 0,
-    extensions: ProtocolFeeBasisPointsExtension {
-      protocol_fee_basis_points: (0, 0),
-      next: Void,
-    },
+    extensions: [
+      Pair(
+        0,
+        as_data(
+          ProtocolFeeBasisPointsExtension { protocol_fee_basis_points: (0, 0) },
+        ),
+      ),
+    ],
   }
 }
 
@@ -207,10 +211,16 @@ test example_mainnet_boot_settings_datum() {
       simple_fee: 168_000,
       strategy_fee: 168_000,
       pool_creation_fee: 0,
-      extensions: ProtocolFeeBasisPointsExtension {
-        protocol_fee_basis_points: (30, 30),
-        next: Void,
-      },
+      extensions: [
+        Pair(
+          0,
+          as_data(
+            ProtocolFeeBasisPointsExtension {
+              protocol_fee_basis_points: (0, 0),
+            },
+          ),
+        ),
+      ],
     },
   )
 }

lib/types/settings.ak

@@ -1,5 +1,6 @@
 use aiken/builtin
 use aiken/collection/dict
+use aiken/collection/pairs
 use aiken/crypto.{VerificationKey}
 use cardano/address.{Address, Credential}
 use cardano/assets.{AssetName, PolicyId}
@@ -67,14 +68,12 @@ pub type SettingsDatum {
   /// - publish data for convenient and canonical access by off-chain actors
   /// - expose data to the script conditions in the multisig scripts of the two administrator roles
   /// - expose additional settings for more advanced pool and order types to operate off of
-  extensions: ProtocolFeeBasisPointsExtension,
+  extensions: Pairs<Int, Data>,
 }
 
 pub type ProtocolFeeBasisPointsExtension {
   /// The default protocol fee basis points to charge on each trade for bid (A -> B) and ask (B -> A) orders, for pools that don't override it
   protocol_fee_basis_points: (Int, Int),
-  /// Pointing to next extension in the future
-  next: Data,
 }
 
 /// The settings redeemer can be spent for two different purposes
@@ -88,6 +87,19 @@ pub type SettingsRedeemer {
 /// The name of the token that authenticates the settings UTXO
 pub const settings_nft_name: AssetName = "settings"
 
+pub fn find_protocol_fee_extension(
+  settings: SettingsDatum,
+) -> Option<ProtocolFeeBasisPointsExtension> {
+  let maybe_extension = pairs.get_first(settings.extensions, 0)
+  when maybe_extension is {
+    Some(extension_data) -> {
+      expect extension: ProtocolFeeBasisPointsExtension = extension_data
+      Some(extension)
+    }
+    None -> None
+  }
+}
+
 /// Scan over the list of reference inputs to find the settings datum, and ensure it's the correct one
 /// Note that this makes the assumption that the settings datum is the first reference input, for performance
 /// This means that when storing reference scripts on-chain, there needs to be a small amount of "farming" to select

validators/pool.ak

@@ -24,7 +24,10 @@ use types/pool.{
   MintLP, PoolMintRedeemer, PoolRedeemer, PoolScoop, StablePoolDatum,
   UpdatePoolFees, WithdrawFees,
 } as types_pool
-use types/settings.{SettingsDatum, find_settings_datum}
+use types/settings.{
+  ProtocolFeeBasisPointsExtension, SettingsDatum, find_protocol_fee_extension,
+  find_settings_datum,
+}
 
 /// An implementation of a curve-like "Stableswap" invariant that enables more efficient trades for stablecoin pairs.
 ///
@@ -518,6 +521,9 @@ validator pool(
         //    and potentially even on access UIs for the Sundae protocol
         expect metadata_output.datum == InlineDatum(Void)
 
+        expect Some(protocol_fee_extension) =
+          find_protocol_fee_extension(settings_datum)
+
         // And check that the datum is initialized correctly; This is part of why we have a minting policy handling this,
         // as it allows us to authenticate the providence of the datum.
         // A datum is valid so long as
@@ -541,7 +547,7 @@ validator pool(
             shared.fees_in_legal_range(
               pool_output_datum.protocol_fee_basis_points.2nd,
             ),
-            settings_datum.extensions.protocol_fee_basis_points == pool_output_datum.protocol_fee_basis_points,
+            protocol_fee_extension.protocol_fee_basis_points == pool_output_datum.protocol_fee_basis_points,
             pool_output_datum.linear_amplification > 0,
             liquidity_invariant(
               reserve_a * calc_precision,

validators/tests/pool.ak

@@ -37,7 +37,7 @@ use types/pool.{
   UpdatePoolFees, WithdrawFees,
 }
 use types/settings.{
-  ProtocolFeeBasisPointsExtension, SettingsDatum, settings_nft_name,
+  SettingsDatum, settings_nft_name,
 }
 
 type ScoopTestOptions {
@@ -383,10 +383,7 @@ test scooper_not_in_settings() fail {
             simple_fee: 2_500_000,
             strategy_fee: 5_000_000,
             pool_creation_fee: 0,
-            extensions: ProtocolFeeBasisPointsExtension {
-              protocol_fee_basis_points: (0, 0),
-              next: Void,
-            },
+            extensions: [],
           },
         ),
       ),

validators/tests/pool.manage.ak

@@ -17,7 +17,7 @@ use sundae/multisig.{MultisigScript}
 use tests/constants
 use tests/examples/ex_settings.{mk_valid_settings_input}
 use types/pool.{ManageRedeemer, StablePoolDatum}
-use types/settings.{ProtocolFeeBasisPointsExtension, SettingsDatum}
+use types/settings.{SettingsDatum}
 
 const settings_policy_id: PolicyId =
   #"00000000000000000000000000000000000000000000000000000000"
@@ -388,10 +388,7 @@ fn scenario_settings_input_baseline(
           simple_fee: 2_500_000,
           strategy_fee: 5_000_000,
           pool_creation_fee: 0,
-          extensions: ProtocolFeeBasisPointsExtension {
-            protocol_fee_basis_points: (0, 0),
-            next: Void,
-          },
+          extensions: [],
         }
       },
     )

validators/tests/settings.ak

@@ -12,10 +12,7 @@ use tx_util/builder.{
   add_asset_to_tx_output, add_tx_input, add_tx_output, build_txn_context,
   mint_assets, new_tx_input, new_tx_output, with_asset_of_tx_input,
 }
-use types/settings.{
-  ProtocolFeeBasisPointsExtension, SettingsAdminUpdate, SettingsDatum,
-  settings_nft_name,
-}
+use types/settings.{SettingsAdminUpdate, SettingsDatum, settings_nft_name}
 
 fn test_mint_settings(settings_nfts_count: Int) {
   let settings_nft =
@@ -95,10 +92,7 @@ fn mk_valid_settings_datum(scoopers: List<ByteArray>) -> SettingsDatum {
     simple_fee: 2_500_000,
     strategy_fee: 5_000_000,
     pool_creation_fee: 0,
-    extensions: ProtocolFeeBasisPointsExtension {
-      protocol_fee_basis_points: (0, 0),
-      next: Void,
-    },
+    extensions: [],
   }
 }