Add transaction-builder suport for TZE-bearing transactions.

Cargo.toml

@@ -5,7 +5,7 @@ members = [
     "group",
     "pairing",
     "zcash_client_backend",
-    "zcash_extensions_api",
+    "zcash_extensions",
     "zcash_history",
     "zcash_primitives",
     "zcash_proofs",

zcash_extensions/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "zcash_extensions"
+description = "TBD"
+version = "0.0.0"
+authors = ["Jack Grigg <jack@z.cash>", "Kris Nuttycombe <kris@z.cash>"]
+homepage = "https://github.com/zcash/librustzcash"
+repository = "https://github.com/zcash/librustzcash"
+license = "MIT OR Apache-2.0"
+edition = "2018"
+
+[dependencies]
+blake2b_simd = "0.5"
+zcash_primitives = { version = "0.2", path = "../zcash_primitives" }
+
+[dev-dependencies]
+ff = { version = "0.6", path = "../ff" }
+pairing = { version = "0.16", path = "../pairing" }
+zcash_proofs = { path = "../zcash_proofs" }
+rand_core = "0.5.1"

zcash_primitives/src/consensus/extensions/transparent.rs → zcash_extensions/src/consensus/transparent.rs

@@ -1,33 +1,33 @@
 //! Consensus logic for Transparent Zcash Extensions.
 
 use std::convert::TryFrom;
-use zcash_extensions_api::transparent::{Error, Extension, Precondition, Witness};
+use zcash_primitives::extensions::transparent::{Error, Extension, Precondition, Witness};
+use zcash_primitives::transaction::components::TzeOut;
+use zcash_primitives::transaction::Transaction;
 
-use crate::extensions::transparent::demo;
-use crate::transaction::components::TzeOut;
-use crate::transaction::Transaction;
+use crate::transparent::demo;
 
 /// The set of programs that have assigned type IDs within the Zcash consensus rules.
 #[derive(Debug, Clone, Copy)]
 pub enum ExtensionId {
     Demo,
 }
 
-pub struct InvalidExtId(usize);
+pub struct InvalidExtId(u32);
 
-impl TryFrom<usize> for ExtensionId {
+impl TryFrom<u32> for ExtensionId {
     type Error = InvalidExtId;
 
-    fn try_from(t: usize) -> Result<Self, Self::Error> {
+    fn try_from(t: u32) -> Result<Self, Self::Error> {
         match t {
             0 => Ok(ExtensionId::Demo),
             n => Err(InvalidExtId(n)),
         }
     }
 }
 
-impl From<ExtensionId> for usize {
-    fn from(type_id: ExtensionId) -> usize {
+impl From<ExtensionId> for u32 {
+    fn from(type_id: ExtensionId) -> u32 {
         match type_id {
             ExtensionId::Demo => 0,
         }

zcash_extensions/src/lib.rs

@@ -0,0 +1,2 @@
+pub mod consensus;
+pub mod transparent;

zcash_extensions/src/transparent.rs

@@ -0,0 +1,3 @@
+//! Zcash transparent extensions.
+
+pub mod demo;