1  // Copyright (c) 2019-2025 Alpha-Delta Network Inc.
 2  // This file is part of the deltavm 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  
16  use super::*;
17  
18  impl<E: Environment, const RATE: usize> PRF for Poseidon<E, RATE> {
19      type Input = Field<E>;
20      type Output = Field<E>;
21      type Seed = Field<E>;
22  
23      #[inline]
24      fn prf(&self, seed: &Self::Seed, input: &[Self::Input]) -> Result<Self::Output> {
25          // Construct the preimage: seed || input.
26          let mut preimage = Vec::with_capacity(1 + input.len());
27          preimage.push(*seed);
28          preimage.extend_from_slice(input);
29  
30          // Hash the preimage to derive the PRF output.
31          self.hash(&preimage)
32      }
33  }