clvm_traits/
clvm_decoder.rs

1use clvmr::{allocator::SExp, Allocator, Atom, NodePtr};
2use num_bigint::BigInt;
3
4use crate::{
5    destructure_list, destructure_quote, match_list, match_quote, FromClvm, FromClvmError,
6    MatchByte,
7};
8
9pub trait ClvmDecoder: Sized {
10    type Node: Clone + FromClvm<Self>;
11
12    fn decode_atom(&self, node: &Self::Node) -> Result<Atom<'_>, FromClvmError>;
13    fn decode_pair(&self, node: &Self::Node) -> Result<(Self::Node, Self::Node), FromClvmError>;
14
15    fn decode_bigint(&self, node: &Self::Node) -> Result<BigInt, FromClvmError> {
16        let atom = self.decode_atom(node)?;
17        Ok(BigInt::from_signed_bytes_be(atom.as_ref()))
18    }
19
20    fn decode_curried_arg(
21        &self,
22        node: &Self::Node,
23    ) -> Result<(Self::Node, Self::Node), FromClvmError> {
24        let destructure_list!(_, destructure_quote!(first), rest) =
25            <match_list!(MatchByte<4>, match_quote!(Self::Node), Self::Node)>::from_clvm(
26                self,
27                node.clone(),
28            )?;
29        Ok((first, rest))
30    }
31
32    /// This is a helper function that just calls `clone` on the node.
33    /// It's required only because the compiler can't infer that `N` is `Clone`,
34    /// since there's no `Clone` bound on the `FromClvm` trait.
35    fn clone_node(&self, node: &Self::Node) -> Self::Node {
36        node.clone()
37    }
38}
39
40impl ClvmDecoder for Allocator {
41    type Node = NodePtr;
42
43    fn decode_atom(&self, node: &Self::Node) -> Result<Atom<'_>, FromClvmError> {
44        if let SExp::Atom = self.sexp(*node) {
45            Ok(self.atom(*node))
46        } else {
47            Err(FromClvmError::ExpectedAtom)
48        }
49    }
50
51    fn decode_pair(&self, node: &Self::Node) -> Result<(Self::Node, Self::Node), FromClvmError> {
52        if let SExp::Pair(first, rest) = self.sexp(*node) {
53            Ok((first, rest))
54        } else {
55            Err(FromClvmError::ExpectedPair)
56        }
57    }
58
59    fn decode_bigint(&self, node: &Self::Node) -> Result<BigInt, FromClvmError> {
60        if let SExp::Atom = self.sexp(*node) {
61            Ok(self.number(*node))
62        } else {
63            Err(FromClvmError::ExpectedAtom)
64        }
65    }
66}
67
68impl FromClvm<Allocator> for NodePtr {
69    fn from_clvm(_decoder: &Allocator, node: NodePtr) -> Result<Self, FromClvmError> {
70        Ok(node)
71    }
72}
clvm_traits/clvm_decoder.rs

clvm_traits/
clvm_decoder.rs
