prattle/
node.rs

1// node.rs - MIT License
2//  MIT License
3//  Copyright (c) 2018 Tyler Laing (ZerothLaw)
4// 
5//  Permission is hereby granted, free of charge, to any person obtaining a copy
6//  of this software and associated documentation files (the "Software"), to deal
7//  in the Software without restriction, including without limitation the rights
8//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9//  copies of the Software, and to permit persons to whom the Software is
10//  furnished to do so, subject to the following conditions:
11// 
12//  The above copyright notice and this permission notice shall be included in all
13//  copies or substantial portions of the Software.
14// 
15//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21//  SOFTWARE.
22
23//! # Node enum
24//! 
25//! This is a general purpose enum construct for representing parse trees. 
26//! 
27//! In the most general case, you have simple nodes (representing concrete constructs 
28//! like identifiers or numbers), and composite nodes, which has a single root token
29//! (for example an operator), and zero-to-many child nodes. 
30//! 
31//! It should be fairly easy to take an AST built with this type into something more
32//! specialized for your language. The idea is that the parser needs to know
33//! what type is being returned.
34//! 
35// TODO: Make this a trait and let users manage ASTNode definition and construction? 
36
37use std::fmt::{Display, Error, Formatter};
38
39use token::Token;
40
41#[derive(Debug, Clone, Eq, Hash, Ord, PartialEq, PartialOrd)]
42pub enum Node<T: Token> {
43    Simple(T), 
44    Composite {
45        token: T,
46        children: Vec<Node<T>>
47    }
48}
49
50impl<T: Token> Display for Node<T> {
51    fn fmt(&self, f: &mut Formatter) -> Result<(), Error>{
52        write!(f,
53            "{}", 
54            match self {
55                Node::Simple(ref t) => format!("Simple({})", t), 
56                Node::Composite{
57                    token: ref t, 
58                    children: ref childs
59                } => format!("Composite(token: {}, children: {:?})", t, childs )
60            }
61        )
62    }
63}
64
65#[cfg(test)]
66mod test {
67    use super::*;
68    //Catch Send/Sync changes
69    #[test]
70    fn test_node_send() {
71        fn assert_send<T: Send>() {}
72        assert_send::<Node<String>>();
73    }
74
75    #[test]
76    fn test_node_sync() {
77        fn assert_sync<T: Sync>() {}
78        assert_sync::<Node<String>>();
79    }
80}
prattle/node.rs

prattle/
node.rs
