snarkvm_circuit_program/data/future/
find.rs

1// Copyright (c) 2019-2025 Provable Inc.
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use super::*;
17
18impl<A: Aleo> Future<A> {
19    /// Returns the value from the given path.
20    pub fn find<A0: Into<Access<A>> + Clone + Debug>(&self, path: &[A0]) -> Result<Value<A>> {
21        // Ensure the path is not empty.
22        ensure!(!path.is_empty(), "Attempted to find an argument with an empty path.");
23
24        // A helper enum to track the the argument.
25        enum ArgumentRefType<'a, A: Aleo> {
26            /// A plaintext type.
27            Plaintext(&'a Plaintext<A>),
28            /// A future.
29            Future(&'a Future<A>),
30        }
31
32        // Initialize a value starting from the top-level.
33        let mut value = ArgumentRefType::Future(self);
34
35        // Iterate through the path to retrieve the value.
36        for access in path.iter() {
37            let access = access.clone().into();
38            match (value, &access) {
39                (ArgumentRefType::Plaintext(Plaintext::Struct(members, ..)), Access::Member(identifier)) => {
40                    match members.get(identifier) {
41                        // Retrieve the member and update `value` for the next iteration.
42                        Some(member) => value = ArgumentRefType::Plaintext(member),
43                        // Halts if the member does not exist.
44                        None => bail!("Failed to locate member '{identifier}''"),
45                    }
46                }
47                (ArgumentRefType::Plaintext(Plaintext::Array(array, ..)), Access::Index(index)) => {
48                    let index = match index.eject_mode() {
49                        Mode::Constant => index.eject_value(),
50                        _ => bail!("'{index}' must be a constant"),
51                    };
52                    match array.get(*index as usize) {
53                        // Retrieve the element and update `value` for the next iteration.
54                        Some(element) => value = ArgumentRefType::Plaintext(element),
55                        // Halts if the index is out of bounds.
56                        None => bail!("Index '{index}' is out of bounds"),
57                    }
58                }
59                (ArgumentRefType::Future(future), Access::Index(index)) => {
60                    let index = match index.eject_mode() {
61                        Mode::Constant => index.eject_value(),
62                        _ => bail!("'{index}' must be a constant"),
63                    };
64                    match future.arguments.get(*index as usize) {
65                        // If the argument is a future, update `value` for the next iteration.
66                        Some(Argument::Future(future)) => value = ArgumentRefType::Future(future),
67                        // If the argument is a plaintext, update `value` for the next iteration.
68                        Some(Argument::Plaintext(plaintext)) => value = ArgumentRefType::Plaintext(plaintext),
69                        // Halts if the index is out of bounds.
70                        None => bail!("Index '{index}' is out of bounds"),
71                    }
72                }
73                _ => bail!("Invalid access `{access}`"),
74            }
75        }
76
77        match value {
78            ArgumentRefType::Plaintext(plaintext) => Ok(Value::Plaintext(plaintext.clone())),
79            ArgumentRefType::Future(future) => Ok(Value::Future(future.clone())),
80        }
81    }
82}
snarkvm_circuit_program/data/future/find.rs

snarkvm_circuit_program/data/future/
find.rs
