[framework] Adds bcs::peel_enum_tag

crates/sui-framework/docs/sui/bcs.md

@@ -60,6 +60,7 @@ let leftovers = prepared.into_remainder_bytes();
 -  [Function `peel_vec_u64`](#sui_bcs_peel_vec_u64)
 -  [Function `peel_vec_u128`](#sui_bcs_peel_vec_u128)
 -  [Function `peel_vec_u256`](#sui_bcs_peel_vec_u256)
+-  [Function `peel_enum_tag`](#sui_bcs_peel_enum_tag)
 -  [Macro function `peel_option`](#sui_bcs_peel_option)
 -  [Function `peel_option_address`](#sui_bcs_peel_option_address)
 -  [Function `peel_option_bool`](#sui_bcs_peel_option_bool)
@@ -766,6 +767,46 @@ Peel a vector of <code>u256</code> from serialized bytes.
 
 
 
+</details>
+
+<a name="sui_bcs_peel_enum_tag"></a>
+
+## Function `peel_enum_tag`
+
+Peel enum from serialized bytes, where <code>$f</code> takes a <code>tag</code> value and returns
+the corresponding enum variant. Move enums are limited to 127 variants,
+however the tag can be any <code>u32</code> value.
+
+Example:
+```rust
+let my_enum = match (bcs.peel_enum_tag()) {
+0 => Enum::Empty,
+1 => Enum::U8(bcs.peel_u8()),
+2 => Enum::U16(bcs.peel_u16()),
+3 => Enum::Struct { a: bcs.peel_address(), b: bcs.peel_u8() },
+_ => abort,
+};
+```
+
+
+<pre><code><b>public</b> <b>fun</b> <a href="../sui/bcs.md#sui_bcs_peel_enum_tag">peel_enum_tag</a>(<a href="../sui/bcs.md#sui_bcs">bcs</a>: &<b>mut</b> <a href="../sui/bcs.md#sui_bcs_BCS">sui::bcs::BCS</a>): u32
+</code></pre>
+
+
+
+<details>
+<summary>Implementation</summary>
+
+
+<pre><code><b>public</b> <b>fun</b> <a href="../sui/bcs.md#sui_bcs_peel_enum_tag">peel_enum_tag</a>(<a href="../sui/bcs.md#sui_bcs">bcs</a>: &<b>mut</b> <a href="../sui/bcs.md#sui_bcs_BCS">BCS</a>): u32 {
+    <b>let</b> tag = <a href="../sui/bcs.md#sui_bcs">bcs</a>.<a href="../sui/bcs.md#sui_bcs_peel_vec_length">peel_vec_length</a>();
+    <b>assert</b>!(tag &lt;= <a href="../std/u32.md#std_u32_max_value">std::u32::max_value</a>!() <b>as</b> u64, <a href="../sui/bcs.md#sui_bcs_EOutOfRange">EOutOfRange</a>);
+    tag <b>as</b> u32
+}
+</code></pre>
+
+
+
 </details>
 
 <a name="sui_bcs_peel_option"></a>

crates/sui-framework/packages/sui-framework/sources/bcs.move

@@ -217,6 +217,28 @@ public fun peel_vec_u256(bcs: &mut BCS): vector<u256> {
     bcs.peel_vec!(|bcs| bcs.peel_u256())
 }
 
+// === Enum ===
+
+/// Peel enum from serialized bytes, where `$f` takes a `tag` value and returns
+/// the corresponding enum variant. Move enums are limited to 127 variants,
+/// however the tag can be any `u32` value.
+///
+/// Example:
+/// ```rust
+/// let my_enum = match (bcs.peel_enum_tag()) {
+///    0 => Enum::Empty,
+///    1 => Enum::U8(bcs.peel_u8()),
+///    2 => Enum::U16(bcs.peel_u16()),
+///    3 => Enum::Struct { a: bcs.peel_address(), b: bcs.peel_u8() },
+///    _ => abort,
+/// };
+/// ```
+public fun peel_enum_tag(bcs: &mut BCS): u32 {
+    let tag = bcs.peel_vec_length();
+    assert!(tag <= std::u32::max_value!() as u64, EOutOfRange);
+    tag as u32
+}
+
 // === Option<T> ===
 
 /// Peel `Option<$T>` from serialized bytes, where `$peel: |&mut BCS| -> $T` gives the

crates/sui-framework/packages/sui-framework/tests/bcs_tests.move

@@ -14,6 +14,12 @@ module sui::bcs_tests {
     const U256_MAX: u256 =
         0xFFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF;
 
+    public enum Enum has copy, drop {
+        Empty,
+        U8(u8),
+        U16(u16),
+    }
+
     public struct Info has copy, drop {
         a: bool,
         b: u8,
@@ -182,6 +188,22 @@ module sui::bcs_tests {
         );
     }
 
+    #[test]
+    fun test_enum() {
+        let enum_cases = vector[Enum::Empty, Enum::U8(1), Enum::U16(2)];
+        cases!(enum_cases, |bytes| bytes.peel_test_enum());
+    }
+
+    use fun peel_test_enum as BCS.peel_test_enum;
+    fun peel_test_enum(bytes: &mut BCS): Enum {
+        match (bytes.peel_enum_tag()) {
+            0 => Enum::Empty,
+            1 => Enum::U8(bytes.peel_u8()),
+            2 => Enum::U16(bytes.peel_u16()),
+            _ => abort,
+        }
+    }
+
     #[test]
     fun test_complex() {
         let vec_vec_u8_cases = vector[vector[], vector[b"hello world"], vector[b"hello", b"world"]];

crates/sui-framework/published_api.txt

@@ -1507,6 +1507,9 @@ peel_vec_u128
 peel_vec_u256
 	public fun
 	0x2::bcs
+peel_enum_tag
+	public fun
+	0x2::bcs
 peel_option_address
 	public fun
 	0x2::bcs

crates/sui-open-rpc/spec/openrpc.json

@@ -1294,7 +1294,7 @@
             "name": "Result",
             "value": {
               "minSupportedProtocolVersion": "1",
-              "maxSupportedProtocolVersion": "73",
+              "maxSupportedProtocolVersion": "74",
               "protocolVersion": "6",
               "featureFlags": {
                 "accept_zklogin_in_multisig": false,

crates/sui-protocol-config/src/lib.rs

@@ -18,7 +18,7 @@ use tracing::{info, warn};
 
 /// The minimum and maximum protocol versions supported by this build.
 const MIN_PROTOCOL_VERSION: u64 = 1;
-const MAX_PROTOCOL_VERSION: u64 = 73;
+const MAX_PROTOCOL_VERSION: u64 = 74;
 
 // Record history of protocol version allocations here:
 //
@@ -213,6 +213,8 @@ const MAX_PROTOCOL_VERSION: u64 = 73;
 //             Enable zstd compression for consensus tonic network in testnet.
 //             Enable smart ancestor selection in mainnet.
 //             Enable probing for accepted rounds in round prober in mainnet
+// Version 74:
+//
 
 #[derive(Copy, Clone, Debug, Hash, Serialize, Deserialize, PartialEq, Eq, PartialOrd, Ord)]
 pub struct ProtocolVersion(u64);
@@ -3195,6 +3197,7 @@ impl ProtocolConfig {
                     cfg.feature_flags
                         .consensus_round_prober_probe_accepted_rounds = true;
                 }
+                74 => {}
                 // Use this template when making changes:
                 //
                 //     // modify an existing constant.