leo_ast/functions/
variant.rs

1// Copyright (C) 2019-2025 Provable Inc.
2// This file is part of the Leo library.
3
4// The Leo library is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8
9// The Leo library is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13
14// You should have received a copy of the GNU General Public License
15// along with the Leo library. If not, see <https://www.gnu.org/licenses/>.
16
17use serde::{Deserialize, Serialize};
18
19use std::fmt;
20
21/// Functions are always one of six variants.
22/// A transition function is permitted the ability to manipulate records.
23/// An asynchronous transition function is a transition function that calls an asynchronous function.
24/// A regular function is not permitted to manipulate records.
25/// An asynchronous function contains on-chain operations.
26/// An inline function is directly copied at the call site.
27#[derive(Copy, Clone, Debug, Default, Serialize, Deserialize, PartialEq, Eq)]
28pub enum Variant {
29    #[default]
30    Inline,
31    Function,
32    Transition,
33    AsyncTransition,
34    AsyncFunction,
35    /// `script` can only appear in test files, and is used for
36    /// tests which are interpreted rather than run on snarkvm using a Ledger and VM.
37    Script,
38}
39
40impl Variant {
41    /// Returns true if the variant is async.
42    pub fn is_async(self) -> bool {
43        matches!(self, Variant::AsyncFunction | Variant::AsyncTransition)
44    }
45
46    /// Returns true if the variant is a transition.
47    pub fn is_transition(self) -> bool {
48        matches!(self, Variant::Transition | Variant::AsyncTransition)
49    }
50
51    /// Returns true if the variant is a function.
52    pub fn is_function(self) -> bool {
53        matches!(self, Variant::AsyncFunction | Variant::Function)
54    }
55
56    /// Is this a `script`?
57    pub fn is_script(self) -> bool {
58        matches!(self, Variant::Script)
59    }
60
61    /// Returns true if the variant is an async function.
62    pub fn is_async_function(self) -> bool {
63        matches!(self, Variant::AsyncFunction)
64    }
65}
66
67impl fmt::Display for Variant {
68    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
69        match self {
70            Self::Inline => write!(f, "inline"),
71            Self::Function => write!(f, "function"),
72            Self::Transition => write!(f, "transition"),
73            Self::AsyncTransition => write!(f, "async transition"),
74            Self::AsyncFunction => write!(f, "async function"),
75            Self::Script => write!(f, "script"),
76        }
77    }
78}