Add a less strict solution representation (#674)

* Add a less strict solution representation

* Use the new representation for solutions

crates/chia-puzzles/src/puzzles/cat.rs

@@ -83,7 +83,7 @@ impl GenesisByCoinIdTailArgs {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct CatSolution<I> {
     pub inner_puzzle_solution: I,
     pub lineage_proof: Option<LineageProof>,

crates/chia-puzzles/src/puzzles/did.rs

@@ -59,7 +59,7 @@ impl DidArgs<TreeHash, TreeHash> {
 
 #[derive(Debug, Clone, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 #[repr(u8)]
 pub enum DidSolution<I> {
     Recover(#[clvm(rest)] Box<DidRecoverySolution>) = 0,
@@ -68,7 +68,7 @@ pub enum DidSolution<I> {
 
 #[derive(Debug, Clone, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct DidRecoverySolution {
     pub amount: u64,
     pub new_inner_puzzle_hash: Bytes32,

crates/chia-puzzles/src/puzzles/nft.rs

@@ -74,7 +74,7 @@ impl NftStateLayerArgs<TreeHash, TreeHash> {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct NftStateLayerSolution<I> {
     pub inner_solution: I,
 }
@@ -121,7 +121,7 @@ impl NftOwnershipLayerArgs<TreeHash, TreeHash> {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct NftOwnershipLayerSolution<I> {
     pub inner_solution: I,
 }

crates/chia-puzzles/src/puzzles/singleton.rs

@@ -57,7 +57,7 @@ impl SingletonStruct {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct SingletonSolution<I> {
     pub lineage_proof: Proof,
     pub amount: u64,
@@ -66,7 +66,7 @@ pub struct SingletonSolution<I> {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct LauncherSolution<T> {
     pub singleton_puzzle_hash: Bytes32,
     pub amount: u64,

crates/chia-puzzles/src/puzzles/standard.rs

@@ -26,7 +26,7 @@ impl StandardArgs {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, ToClvm, FromClvm)]
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[clvm(list)]
+#[clvm(solution)]
 pub struct StandardSolution<P, S> {
     pub original_public_key: Option<PublicKey>,
     pub delegated_puzzle: P,

crates/clvm-derive/src/from_clvm.rs

@@ -43,7 +43,7 @@ fn field_parser_fn_body(
     let decode_next = match repr {
         Repr::Atom | Repr::Transparent => unreachable!(),
         // Decode `(A . B)` pairs for lists.
-        Repr::List => quote!(decode_pair),
+        Repr::List | Repr::Solution => quote!(decode_pair),
         // Decode `(c (q . A) B)` pairs for curried arguments.
         Repr::Curry => quote!(decode_curried_arg),
     };
@@ -150,6 +150,8 @@ fn field_parser_fn_body(
 fn check_rest_value(crate_name: &Ident, repr: Repr) -> TokenStream {
     match repr {
         Repr::Atom | Repr::Transparent => unreachable!(),
+        // We don't need to check the terminator of a solution.
+        Repr::Solution => quote! {},
         Repr::List => {
             // If the last field is not `rest`, we need to check that the `node` is nil.
             // If it's not nil, it's not a proper list, and we should return an error.
@@ -286,7 +288,7 @@ fn impl_for_enum(
             let decode_next = match enum_info.default_repr {
                 Repr::Atom | Repr::Transparent => unreachable!(),
                 // Decode `(A . B)` pairs for lists.
-                Repr::List => quote!(decode_pair),
+                Repr::List | Repr::Solution => quote!(decode_pair),
                 // Decode `(c (q . A) B)` pairs for curried arguments.
                 Repr::Curry => quote!(decode_curried_arg),
             };

crates/clvm-derive/src/parser/attributes.rs

@@ -11,6 +11,8 @@ use syn::{
 pub enum Repr {
     /// Represents `(A . (B . (C . ())))`.
     List,
+    /// The same as `list`, but the terminator doesn't have to be `()`.
+    Solution,
     /// Represents `(c (q . A) (c (q . B) (c (q . C) 1)))`.
     Curry,
     /// Represents the first field `A` on its own, with no other fields allowed.
@@ -22,7 +24,7 @@ pub enum Repr {
 impl Repr {
     pub fn expect(repr: Option<Repr>) -> Repr {
         repr.expect(
-            "missing either `list`, `curry`, `transparent`, or `atom` in `clvm` attribute options",
+            "missing either `list`, `curry`, `solution`, `transparent`, or `atom` in `clvm` attribute options",
         )
     }
 }
@@ -31,6 +33,7 @@ impl fmt::Display for Repr {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.write_str(match self {
             Self::List => "list",
+            Self::Solution => "solution",
             Self::Curry => "curry",
             Self::Transparent => "transparent",
             Self::Atom => "atom",
@@ -75,6 +78,7 @@ impl Parse for ClvmOption {
 
         match ident.to_string().as_str() {
             "list" => Ok(Self::Repr(Repr::List)),
+            "solution" => Ok(Self::Repr(Repr::Solution)),
             "curry" => Ok(Self::Repr(Repr::Curry)),
             "transparent" => Ok(Self::Repr(Repr::Transparent)),
             "atom" => Ok(Self::Repr(Repr::Atom)),

crates/clvm-derive/src/to_clvm.rs

@@ -48,14 +48,16 @@ fn encode_fields(
     let encode_next = match repr {
         Repr::Atom | Repr::Transparent => unreachable!(),
         // Encode `(A . B)` pairs for lists.
-        Repr::List => quote!(encode_pair),
+        Repr::List | Repr::Solution => quote!(encode_pair),
         // Encode `(c (q . A) B)` pairs for curried arguments.
         Repr::Curry => quote!(encode_curried_arg),
     };
 
     let initial_value = match repr {
         Repr::Atom | Repr::Transparent => unreachable!(),
-        Repr::List => quote!(encoder.encode_atom(#crate_name::Atom::Borrowed(&[]))?),
+        Repr::List | Repr::Solution => {
+            quote!(encoder.encode_atom(#crate_name::Atom::Borrowed(&[]))?)
+        }
         Repr::Curry => quote!(encoder.encode_atom(#crate_name::Atom::Borrowed(&[1]))?),
     };
 
@@ -243,7 +245,7 @@ fn impl_for_enum(
             let encode_next = match enum_info.default_repr {
                 Repr::Atom | Repr::Transparent => unreachable!(),
                 // Encode `(A . B)` pairs for lists.
-                Repr::List => quote!(encode_pair),
+                Repr::List | Repr::Solution => quote!(encode_pair),
                 // Encode `(c (q . A) B)` pairs for curried arguments.
                 Repr::Curry => quote!(encode_curried_arg),
             };

crates/clvm-traits/docs/derive_macros.md

@@ -50,6 +50,12 @@ let ptr = value.to_clvm(a).unwrap();
 assert_eq!(Tiers::from_clvm(a, ptr).unwrap(), value);
 ```
 
+### Solution
+
+The solution representation is the same as list, except it does not check the nil terminator when parsing.
+This allows it to be lenient to additional parameters that are in the CLVM object, since they don't affect anything.
+If you want your solution to be parsed strictly, you can use list instead.
+
 ### Curry
 
 This represents the argument part of a curried CLVM program.

crates/clvm-traits/src/lib.rs

@@ -93,6 +93,55 @@ mod derive_tests {
         check(&Struct { a: 52, b: -32 }, "ff3481e0");
     }
 
+    #[test]
+    fn test_solution_struct() {
+        #[derive(Debug, ToClvm, FromClvm, PartialEq)]
+        #[clvm(solution)]
+        struct Struct {
+            a: u64,
+            b: i32,
+        }
+
+        // Includes the nil terminator.
+        check(&Struct { a: 52, b: -32 }, "ff34ff81e080");
+
+        // Allows additional parameters.
+        let mut allocator = Allocator::new();
+        let ptr = clvm_list!(100, 200, 300, 400)
+            .to_clvm(&mut allocator)
+            .unwrap();
+        let value = Struct::from_clvm(&allocator, ptr).unwrap();
+        assert_eq!(value, Struct { a: 100, b: 200 });
+
+        // Doesn't allow differing types for the actual solution parameters.
+        let mut allocator = Allocator::new();
+        let ptr = clvm_list!([1, 2, 3], 200, 300)
+            .to_clvm(&mut allocator)
+            .unwrap();
+        Struct::from_clvm(&allocator, ptr).unwrap_err();
+    }
+
+    #[test]
+    fn test_solution_struct_with_rest() {
+        #[derive(Debug, ToClvm, FromClvm, PartialEq)]
+        #[clvm(solution)]
+        struct Struct {
+            a: u64,
+            #[clvm(rest)]
+            b: i32,
+        }
+
+        // Does not include the nil terminator.
+        check(&Struct { a: 52, b: -32 }, "ff3481e0");
+
+        // Does not allow additional parameters, since it consumes the rest.
+        let mut allocator = Allocator::new();
+        let ptr = clvm_list!(100, 200, 300, 400)
+            .to_clvm(&mut allocator)
+            .unwrap();
+        Struct::from_clvm(&allocator, ptr).unwrap_err();
+    }
+
     #[test]
     fn test_curry_struct() {
         #[derive(Debug, ToClvm, FromClvm, PartialEq)]