zcash_primitives: Remove and relocate `InputView` traits.

zcash_client_backend/CHANGELOG.md

@@ -28,7 +28,7 @@ and this library adheres to Rust's notion of
   - `wallet::input_selection::ShieldingSelector` has been
     factored out from the `InputSelector` trait to separate out transparent
     functionality and move it behind the `transparent-inputs` feature flag.
-- `zcash_client_backend::fees::standard`
+- `zcash_client_backend::fees::{standard, sapling}`
 - `zcash_client_backend::wallet`:
   - `WalletNote`
   - `ReceivedNote`

zcash_client_backend/src/data_api/wallet/input_selection.rs

@@ -10,7 +10,6 @@ use zcash_primitives::{
     transaction::{
         components::{
             amount::{BalanceError, NonNegativeAmount},
-            sapling::fees as sapling,
             TxOut,
         },
         fees::FeeRule,
@@ -21,7 +20,7 @@ use zcash_primitives::{
 use crate::{
     address::{RecipientAddress, UnifiedAddress},
     data_api::SaplingInputSource,
-    fees::{ChangeError, ChangeStrategy, DustOutputPolicy, TransactionBalance},
+    fees::{sapling, ChangeError, ChangeStrategy, DustOutputPolicy, TransactionBalance},
     wallet::{ReceivedNote, WalletTransparentOutput},
     zip321::TransactionRequest,
 };

zcash_client_backend/src/fees.rs

@@ -6,15 +6,14 @@ use zcash_primitives::{
     transaction::{
         components::{
             amount::{BalanceError, NonNegativeAmount},
-            sapling::fees as sapling,
-            transparent::fees as transparent,
             OutPoint,
         },
-        fees::FeeRule,
+        fees::{transparent, FeeRule},
     },
 };
 
 pub mod fixed;
+pub mod sapling;
 pub mod standard;
 pub mod zip317;
 
@@ -260,12 +259,16 @@ pub trait ChangeStrategy {
 
 #[cfg(test)]
 pub(crate) mod tests {
-    use zcash_primitives::transaction::components::{
+    use zcash_primitives::transaction::{
+        components::{
             amount::NonNegativeAmount,
-        sapling::fees as sapling,
+            transparent::{OutPoint, TxOut},
-        transparent::{fees as transparent, OutPoint, TxOut},
+        },
+        fees::transparent,
     };
 
+    use super::sapling;
+
     #[derive(Debug)]
     pub(crate) struct TestTransparentInput {
         pub outpoint: OutPoint,

zcash_client_backend/src/fees/fixed.rs

@@ -4,17 +4,14 @@ use zcash_primitives::{
     consensus::{self, BlockHeight},
     memo::MemoBytes,
     transaction::{
-        components::{
+        components::amount::{BalanceError, NonNegativeAmount},
-            amount::{BalanceError, NonNegativeAmount},
+        fees::{fixed::FeeRule as FixedFeeRule, transparent, FeeRule},
-            sapling::fees as sapling,
-            transparent::fees as transparent,
-        },
-        fees::{fixed::FeeRule as FixedFeeRule, FeeRule},
     },
 };
 
 use super::{
-    ChangeError, ChangeStrategy, ChangeValue, DustAction, DustOutputPolicy, TransactionBalance,
+    sapling, ChangeError, ChangeStrategy, ChangeValue, DustAction, DustOutputPolicy,
+    TransactionBalance,
 };
 
 /// A change strategy that and proposes change as a single output to the most current supported

zcash_client_backend/src/fees/sapling.rs

@@ -0,0 +1,60 @@
+//! Types related to computation of fees and change related to the Sapling components
+//! of a transaction.
+
+use std::convert::Infallible;
+
+use zcash_primitives::{
+    sapling::builder::{SaplingOutputInfo, SpendDescriptionInfo},
+    transaction::components::amount::NonNegativeAmount,
+};
+
+/// A trait that provides a minimized view of a Sapling input suitable for use in
+/// fee and change calculation.
+pub trait InputView<NoteRef> {
+    /// An identifier for the input being spent.
+    fn note_id(&self) -> &NoteRef;
+    /// The value of the input being spent.
+    fn value(&self) -> NonNegativeAmount;
+}
+
+impl<N> InputView<N> for Infallible {
+    fn note_id(&self) -> &N {
+        unreachable!()
+    }
+    fn value(&self) -> NonNegativeAmount {
+        unreachable!()
+    }
+}
+
+// `SpendDescriptionInfo` does not contain a note identifier, so we can only implement
+// `InputView<()>`
+impl InputView<()> for SpendDescriptionInfo {
+    fn note_id(&self) -> &() {
+        &()
+    }
+
+    fn value(&self) -> NonNegativeAmount {
+        NonNegativeAmount::try_from(self.value())
+            .expect("An existing note to be spent must have a valid amount value.")
+    }
+}
+
+/// A trait that provides a minimized view of a Sapling output suitable for use in
+/// fee and change calculation.
+pub trait OutputView {
+    /// The value of the output being produced.
+    fn value(&self) -> NonNegativeAmount;
+}
+
+impl OutputView for SaplingOutputInfo {
+    fn value(&self) -> NonNegativeAmount {
+        NonNegativeAmount::try_from(self.value())
+            .expect("Output values should be checked at construction.")
+    }
+}
+
+impl OutputView for Infallible {
+    fn value(&self) -> NonNegativeAmount {
+        unreachable!()
+    }
+}

zcash_client_backend/src/fees/standard.rs

@@ -4,18 +4,19 @@ use zcash_primitives::{
     consensus::{self, BlockHeight},
     memo::MemoBytes,
     transaction::{
-        components::{
+        components::amount::NonNegativeAmount,
-            amount::NonNegativeAmount, sapling::fees as sapling, transparent::fees as transparent,
-        },
         fees::{
             fixed::FeeRule as FixedFeeRule,
+            transparent,
             zip317::{FeeError as Zip317FeeError, FeeRule as Zip317FeeRule},
             StandardFeeRule,
         },
     },
 };
 
-use super::{fixed, zip317, ChangeError, ChangeStrategy, DustOutputPolicy, TransactionBalance};
+use super::{
+    fixed, sapling, zip317, ChangeError, ChangeStrategy, DustOutputPolicy, TransactionBalance,
+};
 
 /// A change strategy that proposes change as a single output to the most current supported
 /// shielded pool and delegates fee calculation to the provided fee rule.

zcash_client_backend/src/fees/zip317.rs

@@ -8,12 +8,9 @@ use zcash_primitives::{
     consensus::{self, BlockHeight},
     memo::MemoBytes,
     transaction::{
-        components::{
+        components::amount::{BalanceError, NonNegativeAmount},
-            amount::{BalanceError, NonNegativeAmount},
-            sapling::fees as sapling,
-            transparent::fees as transparent,
-        },
         fees::{
+            transparent,
             zip317::{FeeError as Zip317FeeError, FeeRule as Zip317FeeRule},
             FeeRule,
         },
@@ -21,7 +18,8 @@ use zcash_primitives::{
 };
 
 use super::{
-    ChangeError, ChangeStrategy, ChangeValue, DustAction, DustOutputPolicy, TransactionBalance,
+    sapling, ChangeError, ChangeStrategy, ChangeValue, DustAction, DustOutputPolicy,
+    TransactionBalance,
 };
 
 /// A change strategy that and proposes change as a single output to the most current supported

zcash_client_backend/src/wallet.rs

@@ -10,15 +10,15 @@ use zcash_primitives::{
     transaction::{
         components::{
             amount::NonNegativeAmount,
-            sapling::fees as sapling_fees,
+            transparent::{OutPoint, TxOut},
-            transparent::{self, OutPoint, TxOut},
         },
+        fees::transparent as transparent_fees,
         TxId,
     },
     zip32::{AccountId, Scope},
 };
 
-use crate::{address::UnifiedAddress, PoolType, ShieldedProtocol};
+use crate::{address::UnifiedAddress, fees::sapling as sapling_fees, PoolType, ShieldedProtocol};
 
 /// A unique identifier for a shielded transaction output
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
@@ -122,7 +122,7 @@ impl WalletTransparentOutput {
     }
 }
 
-impl transparent::fees::InputView for WalletTransparentOutput {
+impl transparent_fees::InputView for WalletTransparentOutput {
     fn outpoint(&self) -> &OutPoint {
         &self.outpoint
     }

zcash_primitives/CHANGELOG.md

@@ -19,6 +19,8 @@ and this library adheres to Rust's notion of
   - `builder::{InProgressProofs, Unproven, Proven}`
   - `builder::{InProgressSignatures, Unsigned, PartiallyAuthorized}`
   - `builder::{MaybeSigned, SigningParts}`
+  - `builder::{SpendDescriptionInfo::value}`
+  - `builder::{SaplingOutputInfo}`
   - `bundle` module, containing the following types moved from
     `zcash_primitives::transaction::components::sapling`:
     - `Bundle`
@@ -69,6 +71,8 @@ and this library adheres to Rust's notion of
       - `temporary_zcashd_write_output_v4`
       - `temporary_zcashd_read_v4_components`
       - `temporary_zcashd_write_v4_components`
+  - `components::transparent`:
+    - `builder::TransparentInputInfo`
   - `fees::StandardFeeRule`
   - Constants in `fees::zip317`:
     - `MARGINAL_FEE`
@@ -182,7 +186,14 @@ and this library adheres to Rust's notion of
     argument as the diversifier may be obtained from the note.
   - `components::transparent::TxOut.value` now has type `NonNegativeAmount`
     instead of `Amount`.
+  - `components::transparent::fees` has been moved to 
+    `zcash_primitives::transaction::fees::transparent`
+  - `components::transparent::builder::TransparentBuilder::{inputs, outputs}`
+    have changed to return `&[TransparentInputInfo]` and `&[TxOut]` respectively,
+    in order to avoid coupling to the fee traits.
   - `Unauthorized::SaplingAuth` now has type `InProgress<Proven, Unsigned>`.
+  - `fees::FeeRule::fee_required` now takes an additional `orchard_action_count`
+    argument.
   - The following methods now take `NonNegativeAmount` instead of `Amount`:
     - `builder::Builder::{add_sapling_output, add_transparent_output}`
     - `components::transparent::builder::TransparentBuilder::add_output`
@@ -190,12 +201,9 @@ and this library adheres to Rust's notion of
     - `fees::zip317::FeeRule::non_standard`
   - The following methods now return `NonNegativeAmount` instead of `Amount`:
     - `components::amount::testing::arb_nonnegative_amount`
-    - `components::sapling`:
+    - `fees::transparent`:
-      - `fees::InputView::value`
+      - `InputView::value`
-      - `fees::OutputView::value`
+      - `OutputView::value`
-    - `components::transparent`:
-      - `fees::InputView::value`
-      - `fees::OutputView::value`
     - `fees::FeeRule::{fee_required, fee_required_zfuture}`
     - `fees::fixed::FeeRule::fixed_fee`
     - `fees::zip317::FeeRule::marginal_fee`
@@ -237,6 +245,8 @@ and this library adheres to Rust's notion of
   - `SpendDescription::<Unauthorized>::apply_signature`
   - `Bundle::<Unauthorized>::apply_signatures` (use
     `Bundle::<InProgress<Proven, Unsigned>>::apply_signatures` instead).
+  - The `fees` module was removed. Its contents were unused in this crate,
+    are now instead made available by `zcash_client_backend::fees::sapling`.
 - `impl From<zcash_primitive::components::transaction::Amount> for u64`
 - `zcash_primitives::zip32`:
   - `sapling` module (moved from `zcash_primitives::sapling::zip32`).

zcash_primitives/src/sapling/builder.rs

@@ -25,10 +25,7 @@ use crate::{
         zip32::ExtendedSpendingKey,
         Diversifier, MerklePath, Node, Note, PaymentAddress, ProofGenerationKey, SaplingIvk,
     },
-    transaction::{
+    transaction::builder::Progress,
-        builder::Progress,
-        components::{amount::NonNegativeAmount, sapling::fees},
-    },
 };
 
 /// If there are any shielded inputs, always have at least two shielded outputs, padding
@@ -77,18 +74,6 @@ pub struct SpendDescriptionInfo {
     rcv: ValueCommitTrapdoor,
 }
 
-impl fees::InputView<()> for SpendDescriptionInfo {
-    fn note_id(&self) -> &() {
-        // The builder does not make use of note identifiers, so we can just return the unit value.
-        &()
-    }
-
-    fn value(&self) -> NonNegativeAmount {
-        // An existing note to be spent must have a valid amount value.
-        NonNegativeAmount::from_u64(self.note.value().inner()).unwrap()
-    }
-}
-
 impl SpendDescriptionInfo {
     fn new_internal<R: RngCore>(
         mut rng: &mut R,
@@ -105,6 +90,10 @@ impl SpendDescriptionInfo {
         }
     }
 
+    pub fn value(&self) -> NoteValue {
+        self.note.value()
+    }
+
     fn build<Pr: SpendProver>(
         self,
         anchor: Option<bls12_381::Scalar>,
@@ -154,7 +143,7 @@ impl SpendDescriptionInfo {
 /// A struct containing the information required in order to construct a
 /// Sapling output to a transaction.
 #[derive(Clone)]
-struct SaplingOutputInfo {
+pub struct SaplingOutputInfo {
     /// `None` represents the `ovk = ⊥` case.
     ovk: Option<OutgoingViewingKey>,
     note: Note,
@@ -249,12 +238,13 @@ impl SaplingOutputInfo {
             zkproof,
         )
     }
+
+    pub fn recipient(&self) -> PaymentAddress {
+        self.note.recipient()
     }
 
-impl fees::OutputView for SaplingOutputInfo {
+    pub fn value(&self) -> NoteValue {
-    fn value(&self) -> NonNegativeAmount {
+        self.note.value()
-        NonNegativeAmount::from_u64(self.note.value().inner())
-            .expect("Note values should be checked at construction.")
     }
 }
 
@@ -317,12 +307,12 @@ impl SaplingBuilder {
 
     /// Returns the list of Sapling inputs that will be consumed by the transaction being
     /// constructed.
-    pub fn inputs(&self) -> &[impl fees::InputView<()>] {
+    pub fn inputs(&self) -> &[SpendDescriptionInfo] {
         &self.spends
     }
 
     /// Returns the Sapling outputs that will be produced by the transaction being constructed
-    pub fn outputs(&self) -> &[impl fees::OutputView] {
+    pub fn outputs(&self) -> &[SaplingOutputInfo] {
         &self.outputs
     }
 

zcash_primitives/src/transaction/builder.rs

@@ -20,8 +20,7 @@ use crate::{
     transaction::{
         components::{
             amount::{Amount, BalanceError},
-            sapling::fees as sapling_fees,
+            transparent::{self, builder::TransparentBuilder, TxOut},
-            transparent::{self, builder::TransparentBuilder},
         },
         fees::FeeRule,
         sighash::{signature_hash, SignableInput},
@@ -31,7 +30,10 @@ use crate::{
 };
 
 #[cfg(feature = "transparent-inputs")]
-use crate::transaction::components::transparent::TxOut;
+use crate::transaction::components::transparent::builder::TransparentInputInfo;
+
+#[cfg(not(feature = "transparent-inputs"))]
+use std::convert::Infallible;
 
 #[cfg(feature = "zfuture")]
 use crate::{
@@ -184,25 +186,26 @@ impl<'a, P, R> Builder<'a, P, R> {
 
     /// Returns the set of transparent inputs currently committed to be consumed
     /// by the transaction.
-    pub fn transparent_inputs(&self) -> &[impl transparent::fees::InputView] {
+    #[cfg(feature = "transparent-inputs")]
+    pub fn transparent_inputs(&self) -> &[TransparentInputInfo] {
         self.transparent_builder.inputs()
     }
 
     /// Returns the set of transparent outputs currently set to be produced by
     /// the transaction.
-    pub fn transparent_outputs(&self) -> &[impl transparent::fees::OutputView] {
+    pub fn transparent_outputs(&self) -> &[TxOut] {
         self.transparent_builder.outputs()
     }
 
     /// Returns the set of Sapling inputs currently committed to be consumed
     /// by the transaction.
-    pub fn sapling_inputs(&self) -> &[impl sapling_fees::InputView<()>] {
+    pub fn sapling_inputs(&self) -> &[sapling::builder::SpendDescriptionInfo] {
         self.sapling_builder.inputs()
     }
 
     /// Returns the set of Sapling outputs currently set to be produced by
     /// the transaction.
-    pub fn sapling_outputs(&self) -> &[impl sapling_fees::OutputView] {
+    pub fn sapling_outputs(&self) -> &[sapling::builder::SaplingOutputInfo] {
         self.sapling_builder.outputs()
     }
 }
@@ -414,10 +417,16 @@ impl<'a, P: consensus::Parameters, R: RngCore + CryptoRng> Builder<'a, P, R> {
     /// This fee is a function of the spends and outputs that have been added to the builder,
     /// pursuant to the specified [`FeeRule`].
     pub fn get_fee<FR: FeeRule>(&self, fee_rule: &FR) -> Result<NonNegativeAmount, FR::Error> {
+        #[cfg(feature = "transparent-inputs")]
+        let transparent_inputs = self.transparent_builder.inputs();
+
+        #[cfg(not(feature = "transparent-inputs"))]
+        let transparent_inputs: &[Infallible] = &[];
+
         fee_rule.fee_required(
             &self.params,
             self.target_height,
-            self.transparent_builder.inputs(),
+            transparent_inputs,
             self.transparent_builder.outputs(),
             self.sapling_builder.inputs().len(),
             self.sapling_builder.bundle_output_count(),
@@ -460,14 +469,28 @@ impl<'a, P: consensus::Parameters, R: RngCore + CryptoRng> Builder<'a, P, R> {
         output_prover: &OP,
         fee_rule: &FR,
     ) -> Result<(Transaction, SaplingMetadata), Error<FR::Error>> {
+        #[cfg(feature = "transparent-inputs")]
+        let transparent_inputs = self.transparent_builder.inputs();
+
+        #[cfg(not(feature = "transparent-inputs"))]
+        let transparent_inputs: &[Infallible] = &[];
+
         let fee = fee_rule
             .fee_required_zfuture(
                 &self.params,
                 self.target_height,
-                self.transparent_builder.inputs(),
+                transparent_inputs,
                 self.transparent_builder.outputs(),
                 self.sapling_builder.inputs().len(),
                 self.sapling_builder.bundle_output_count(),
+                std::cmp::max(
+                    self.orchard_builder
+                        .as_ref()
+                        .map_or(0, |builder| builder.outputs().len()),
+                    self.orchard_builder
+                        .as_ref()
+                        .map_or(0, |builder| builder.spends().len()),
+                ),
                 self.tze_builder.inputs(),
                 self.tze_builder.outputs(),
             )

zcash_primitives/src/transaction/components/sapling.rs

@@ -21,8 +21,6 @@ use crate::{
 
 use super::{Amount, GROTH_PROOF_SIZE};
 
-pub mod fees;
-
 /// Consensus rules (§4.4) & (§4.5):
 /// - Canonical encoding is enforced here.
 /// - "Not small order" is enforced here.

zcash_primitives/src/transaction/components/sapling/fees.rs

@@ -1,20 +0,0 @@
-//! Types related to computation of fees and change related to the Sapling components
-//! of a transaction.
-
-use crate::transaction::components::amount::NonNegativeAmount;
-
-/// A trait that provides a minimized view of a Sapling input suitable for use in
-/// fee and change calculation.
-pub trait InputView<NoteRef> {
-    /// An identifier for the input being spent.
-    fn note_id(&self) -> &NoteRef;
-    /// The value of the input being spent.
-    fn value(&self) -> NonNegativeAmount;
-}
-
-/// A trait that provides a minimized view of a Sapling output suitable for use in
-/// fee and change calculation.
-pub trait OutputView {
-    /// The value of the output being produced.
-    fn value(&self) -> NonNegativeAmount;
-}

zcash_primitives/src/transaction/components/transparent.rs

@@ -10,7 +10,6 @@ use crate::legacy::{Script, TransparentAddress};
 use super::amount::{Amount, BalanceError, NonNegativeAmount};
 
 pub mod builder;
-pub mod fees;
 
 pub trait Authorization: Debug {
     type ScriptSig: Debug + Clone + PartialEq;

zcash_primitives/src/transaction/components/transparent/builder.rs

@@ -7,10 +7,9 @@ use crate::{
     transaction::{
         components::{
             amount::{Amount, BalanceError, NonNegativeAmount},
-            transparent::{self, fees, Authorization, Authorized, Bundle, TxIn, TxOut},
+            transparent::{self, Authorization, Authorized, Bundle, TxIn, TxOut},
         },
         sighash::TransparentAuthorizingContext,
-        OutPoint,
     },
 };
 
@@ -18,6 +17,7 @@ use crate::{
 use {
     crate::transaction::{
         self as tx,
+        components::transparent::OutPoint,
         sighash::{signature_hash, SignableInput, SIGHASH_ALL},
         TransactionData, TxDigests,
     },
@@ -40,25 +40,9 @@ impl fmt::Display for Error {
     }
 }
 
-/// An uninhabited type that allows the type of [`TransparentBuilder::inputs`]
-/// to resolve when the transparent-inputs feature is not turned on.
-#[cfg(not(feature = "transparent-inputs"))]
-#[derive(Debug)]
-enum InvalidTransparentInput {}
-
-#[cfg(not(feature = "transparent-inputs"))]
-impl fees::InputView for InvalidTransparentInput {
-    fn outpoint(&self) -> &OutPoint {
-        panic!("transparent-inputs feature flag is not enabled.");
-    }
-    fn coin(&self) -> &TxOut {
-        panic!("transparent-inputs feature flag is not enabled.");
-    }
-}
-
 #[cfg(feature = "transparent-inputs")]
 #[derive(Debug, Clone)]
-struct TransparentInputInfo {
+pub struct TransparentInputInfo {
     sk: secp256k1::SecretKey,
     pubkey: [u8; secp256k1::constants::PUBLIC_KEY_SIZE],
     utxo: OutPoint,
@@ -66,12 +50,12 @@ struct TransparentInputInfo {
 }
 
 #[cfg(feature = "transparent-inputs")]
-impl fees::InputView for TransparentInputInfo {
+impl TransparentInputInfo {
-    fn outpoint(&self) -> &OutPoint {
+    pub fn outpoint(&self) -> &OutPoint {
         &self.utxo
     }
 
-    fn coin(&self) -> &TxOut {
+    pub fn coin(&self) -> &TxOut {
         &self.coin
     }
 }
@@ -110,19 +94,13 @@ impl TransparentBuilder {
 
     /// Returns the list of transparent inputs that will be consumed by the transaction being
     /// constructed.
-    pub fn inputs(&self) -> &[impl fees::InputView] {
     #[cfg(feature = "transparent-inputs")]
-        return &self.inputs;
+    pub fn inputs(&self) -> &[TransparentInputInfo] {
-
+        &self.inputs
-        #[cfg(not(feature = "transparent-inputs"))]
-        {
-            let invalid: &[InvalidTransparentInput] = &[];
-            invalid
-        }
     }
 
     /// Returns the transparent outputs that will be produced by the transaction being constructed.
-    pub fn outputs(&self) -> &[impl fees::OutputView] {
+    pub fn outputs(&self) -> &[TxOut] {
         &self.vout
     }
 

zcash_primitives/src/transaction/components/tze.rs

@@ -12,7 +12,6 @@ use super::amount::Amount;
 use crate::{extensions::transparent as tze, transaction::TxId};
 
 pub mod builder;
-pub mod fees;
 
 fn to_io_error(_: std::num::TryFromIntError) -> io::Error {
     io::Error::new(io::ErrorKind::InvalidData, "value out of range")

zcash_primitives/src/transaction/components/tze/builder.rs

@@ -9,7 +9,7 @@ use crate::{
         self as tx,
         components::{
             amount::{Amount, BalanceError},
-            tze::{fees, Authorization, Authorized, Bundle, OutPoint, TzeIn, TzeOut},
+            tze::{Authorization, Authorized, Bundle, OutPoint, TzeIn, TzeOut},
         },
     },
 };
@@ -36,16 +36,16 @@ pub struct TzeSigner<'a, BuildCtx> {
 }
 
 #[derive(Clone)]
-struct TzeBuildInput {
+pub struct TzeBuildInput {
     tzein: TzeIn<()>,
     coin: TzeOut,
 }
 
-impl fees::InputView for TzeBuildInput {
+impl TzeBuildInput {
-    fn outpoint(&self) -> &OutPoint {
+    pub fn outpoint(&self) -> &OutPoint {
         &self.tzein.prevout
     }
-    fn coin(&self) -> &TzeOut {
+    pub fn coin(&self) -> &TzeOut {
         &self.coin
     }
 }
@@ -72,11 +72,11 @@ impl<'a, BuildCtx> TzeBuilder<'a, BuildCtx> {
         }
     }
 
-    pub fn inputs(&self) -> &[impl fees::InputView] {
+    pub fn inputs(&self) -> &[TzeBuildInput] {
         &self.vin
     }
 
-    pub fn outputs(&self) -> &[impl fees::OutputView] {
+    pub fn outputs(&self) -> &[TzeOut] {
         &self.vout
     }
 

zcash_primitives/src/transaction/fees.rs

@@ -2,15 +2,16 @@
 
 use crate::{
     consensus::{self, BlockHeight},
-    transaction::components::{amount::NonNegativeAmount, transparent::fees as transparent},
+    transaction::components::amount::NonNegativeAmount,
 };
 
-#[cfg(feature = "zfuture")]
-use crate::transaction::components::tze::fees as tze;
-
 pub mod fixed;
+pub mod transparent;
 pub mod zip317;
 
+#[cfg(feature = "zfuture")]
+pub mod tze;
+
 /// A trait that represents the ability to compute the fees that must be paid
 /// by a transaction having a specified set of inputs and outputs.
 pub trait FeeRule {
@@ -52,6 +53,7 @@ pub trait FutureFeeRule: FeeRule {
         transparent_outputs: &[impl transparent::OutputView],
         sapling_input_count: usize,
         sapling_output_count: usize,
+        orchard_action_count: usize,
         tze_inputs: &[impl tze::InputView],
         tze_outputs: &[impl tze::OutputView],
     ) -> Result<NonNegativeAmount, Self::Error>;

zcash_primitives/src/transaction/fees/fixed.rs

@@ -1,11 +1,11 @@
 use crate::{
     consensus::{self, BlockHeight},
-    transaction::components::{amount::NonNegativeAmount, transparent::fees as transparent},
+    transaction::components::amount::NonNegativeAmount,
-    transaction::fees::zip317,
+    transaction::fees::{transparent, zip317},
 };
 
 #[cfg(feature = "zfuture")]
-use crate::transaction::components::tze::fees as tze;
+use crate::transaction::fees::tze;
 
 /// A fee rule that always returns a fixed fee, irrespective of the structure of
 /// the transaction being constructed.
@@ -72,6 +72,7 @@ impl super::FutureFeeRule for FeeRule {
         _transparent_outputs: &[impl transparent::OutputView],
         _sapling_input_count: usize,
         _sapling_output_count: usize,
+        _orchard_action_count: usize,
         _tze_inputs: &[impl tze::InputView],
         _tze_outputs: &[impl tze::OutputView],
     ) -> Result<NonNegativeAmount, Self::Error> {

zcash_primitives/src/transaction/fees/transparent.rs

@@ -1,12 +1,16 @@
 //! Types related to computation of fees and change related to the transparent components
 //! of a transaction.
 
-use super::TxOut;
+use std::convert::Infallible;
+
 use crate::{
     legacy::Script,
-    transaction::{components::amount::NonNegativeAmount, OutPoint},
+    transaction::components::{amount::NonNegativeAmount, transparent::TxOut, OutPoint},
 };
 
+#[cfg(feature = "transparent-inputs")]
+use crate::transaction::components::transparent::builder::TransparentInputInfo;
+
 /// This trait provides a minimized view of a transparent input suitable for use in
 /// fee and change computation.
 pub trait InputView: std::fmt::Debug {
@@ -16,6 +20,26 @@ pub trait InputView: std::fmt::Debug {
     fn coin(&self) -> &TxOut;
 }
 
+#[cfg(feature = "transparent-inputs")]
+impl InputView for TransparentInputInfo {
+    fn outpoint(&self) -> &OutPoint {
+        self.outpoint()
+    }
+
+    fn coin(&self) -> &TxOut {
+        self.coin()
+    }
+}
+
+impl InputView for Infallible {
+    fn outpoint(&self) -> &OutPoint {
+        unreachable!()
+    }
+    fn coin(&self) -> &TxOut {
+        unreachable!()
+    }
+}
+
 /// This trait provides a minimized view of a transparent output suitable for use in
 /// fee and change computation.
 pub trait OutputView: std::fmt::Debug {

zcash_primitives/src/transaction/fees/tze.rs

@@ -1,10 +1,10 @@
 //! Abstractions and types related to fee calculations for TZE components of a transaction.
 
 use crate::{
-    extensions::transparent::{self as tze},
+    extensions::transparent as tze,
     transaction::components::{
         amount::Amount,
-        tze::{OutPoint, TzeOut},
+        tze::{builder::TzeBuildInput, OutPoint, TzeOut},
     },
 };
 
@@ -17,6 +17,15 @@ pub trait InputView {
     fn coin(&self) -> &TzeOut;
 }
 
+impl InputView for TzeBuildInput {
+    fn outpoint(&self) -> &OutPoint {
+        self.outpoint()
+    }
+    fn coin(&self) -> &TzeOut {
+        self.coin()
+    }
+}
+
 /// This trait provides a minimized view of a TZE output suitable for use in
 /// fee computation.
 pub trait OutputView {

zcash_primitives/src/transaction/fees/zip317.rs

@@ -7,9 +7,12 @@ use core::cmp::max;
 use crate::{
     consensus::{self, BlockHeight},
     legacy::TransparentAddress,
-    transaction::components::{
+    transaction::{
+        components::{
             amount::{BalanceError, NonNegativeAmount},
-        transparent::{fees as transparent, OutPoint},
+            transparent::OutPoint,
+        },
+        fees::transparent,
     },
 };