1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158

// Copyright (C) 2019-2023 Aleo Systems Inc.
// This file is part of the snarkVM library.

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use crate::BooleanTrait;

/// Unary operator for converting to bits.
pub trait ToBits {
    type Boolean: BooleanTrait;

    /// Returns the little-endian bits of the circuit.
    fn to_bits_le(&self) -> Vec<Self::Boolean> {
        let mut bits = vec![];
        self.write_bits_le(&mut bits);
        bits
    }

    fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>);

    /// Returns the big-endian bits of the circuit.
    fn to_bits_be(&self) -> Vec<Self::Boolean> {
        let mut bits = vec![];
        self.write_bits_be(&mut bits);
        bits
    }

    fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>);
}

/********************/
/****** Arrays ******/
/********************/

impl<C: ToBits<Boolean = B>, B: BooleanTrait> ToBits for Vec<C> {
    type Boolean = B;

    /// A helper method to return a concatenated list of little-endian bits from the circuits.
    #[inline]
    fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>) {
        // The vector is order-preserving, meaning the first circuit in is the first circuit bits out.
        self.as_slice().write_bits_le(vec);
    }

    /// A helper method to return a concatenated list of big-endian bits from the circuits.
    #[inline]
    fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>) {
        // The vector is order-preserving, meaning the first circuit in is the first circuit bits out.
        self.as_slice().write_bits_be(vec);
    }
}

impl<C: ToBits<Boolean = B>, B: BooleanTrait, const N: usize> ToBits for [C; N] {
    type Boolean = B;

    /// A helper method to return a concatenated list of little-endian bits from the circuits.
    #[inline]
    fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>) {
        // The slice is order-preserving, meaning the first circuit in is the first circuit bits out.
        self.as_slice().write_bits_le(vec);
    }

    /// A helper method to return a concatenated list of big-endian bits from the circuits.
    #[inline]
    fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>) {
        // The slice is order-preserving, meaning the first circuit in is the first circuit bits out.
        self.as_slice().write_bits_be(vec);
    }
}

impl<C: ToBits<Boolean = B>, B: BooleanTrait> ToBits for &[C] {
    type Boolean = B;

    /// A helper method to return a concatenated list of little-endian bits from the circuits.
    #[inline]
    fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>) {
        // The slice is order-preserving, meaning the first circuit in is the first circuit bits out.
        for elem in self.iter() {
            elem.write_bits_le(vec);
        }
    }

    /// A helper method to return a concatenated list of big-endian bits from the circuits.
    #[inline]
    fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>) {
        // The slice is order-preserving, meaning the first circuit in is the first circuit bits out.
        for elem in self.iter() {
            elem.write_bits_be(vec);
        }
    }
}

/********************/
/****** Tuples ******/
/********************/

/// A helper macro to implement `ToBits` for a tuple of `ToBits` circuits.
macro_rules! to_bits_tuple {
    (($t0:ident, $i0:tt), $(($ty:ident, $idx:tt)),+) => {
        impl<B: BooleanTrait, $t0: ToBits<Boolean = B>, $($ty: ToBits<Boolean = B>),+> ToBits for ($t0, $($ty),+) {
            type Boolean = B;

            /// A helper method to return a concatenated list of little-endian bits from the circuits.
            #[inline]
            fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>) {
                // The tuple is order-preserving, meaning the first circuit in is the first circuit bits out.
                (&self).write_bits_le(vec);
            }

            /// A helper method to return a concatenated list of big-endian bits from the circuits.
            #[inline]
            fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>) {
                // The tuple is order-preserving, meaning the first circuit in is the first circuit bits out.
                (&self).write_bits_be(vec);
            }
        }

        impl<'a, B: BooleanTrait, $t0: ToBits<Boolean = B>, $($ty: ToBits<Boolean = B>),+> ToBits for &'a ($t0, $($ty),+) {
            type Boolean = B;

            /// A helper method to return a concatenated list of little-endian bits from the circuits.
            #[inline]
            fn write_bits_le(&self, vec: &mut Vec<Self::Boolean>) {
                // The tuple is order-preserving, meaning the first circuit in is the first circuit bits out.
                self.$i0.write_bits_le(vec);
                $(self.$idx.write_bits_le(vec);)+
            }

            /// A helper method to return a concatenated list of big-endian bits from the circuits.
            #[inline]
            fn write_bits_be(&self, vec: &mut Vec<Self::Boolean>) {
                // The tuple is order-preserving, meaning the first circuit in is the first circuit bits out.
                self.$i0.write_bits_be(vec);
                $(self.$idx.write_bits_be(vec);)+
            }
        }
    }
}

to_bits_tuple!((C0, 0), (C1, 1));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5), (C6, 6));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5), (C6, 6), (C7, 7));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5), (C6, 6), (C7, 7), (C8, 8));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5), (C6, 6), (C7, 7), (C8, 8), (C9, 9));
to_bits_tuple!((C0, 0), (C1, 1), (C2, 2), (C3, 3), (C4, 4), (C5, 5), (C6, 6), (C7, 7), (C8, 8), (C9, 9), (C10, 10));