nom_operator/
operator.rs

1// Copyright 2017 The nom-operator project developers
2//
3// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
4// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
5// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
6// option. This file may not be copied, modified, or distributed
7// except according to those terms.
8
9//! An Operator wrapper with extra info for parsing
10
11use std::fmt;
12use IResult;
13use Parser;
14
15/// An Operator wrapper with extra info for parsing
16pub struct Operator<O> {
17    /// The underlying operator enum
18    pub op: O,
19
20    /// The associativity of the operator
21    pub associativity: Associativity,
22
23    /// Size of the operator, Unary, Binary, etc...
24    pub size: OperatorSize,
25
26    /// The precedence of the operator
27    /// If * has precedence 10 and - has precedence 9
28    /// the following expression 1 * 2 - 3
29    /// would parse as (1 * 2) - 3
30    pub precedence: usize,
31
32    /// The nom parser function
33    pub parser: Parser,
34}
35
36
37impl<O> Operator<O> {
38    /// Creates a new operator
39    pub fn new(op: O,
40               assoc: Associativity,
41               size: OperatorSize,
42               prec: usize,
43               parser: Parser) -> Self {
44        Operator {
45            op: op,
46            associativity: assoc,
47            size: size,
48            precedence: prec,
49            parser: parser,
50        }
51    }
52}
53
54impl<O: fmt::Debug> fmt::Debug for Operator<O> {
55    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
56        write!(f,
57               "Operator<{:?}>: \n\tAssociativity: {:?}\n\tPrecedence: {}",
58               self.op,
59               self.associativity,
60               self.precedence)
61    }
62}
63
64impl<O: PartialEq> PartialEq for Operator<O> {
65    // TODO: Should we compare the parser?
66    fn eq(&self, other: &Operator<O>) -> bool {
67        self.op == other.op &&
68            self.associativity == other.associativity &&
69            self.precedence == other.precedence
70    }
71}
72
73/// Size of the operator
74#[derive(Debug, Clone, Copy, PartialEq)]
75pub enum OperatorSize {
76    /// Unary operator
77    ///
78    /// ++x
79    Unary,
80
81    /// Binary operator
82    ///
83    /// 5 ^ 5
84    Binary,
85}
86
87
88/// Associativity of the operator
89#[derive(Debug, Clone, Copy, PartialEq)]
90pub enum Associativity {
91    /// Left associative operator
92    ///
93    /// 5 * 5 * 7 = (5 * 5) * 7
94    Left,
95
96    /// Right associative operator
97    ///
98    /// 5 ^ 5 ^ 9 = 5 ^ (5 ^ 9)
99    Right,
100}
101
nom_operator/operator.rs

nom_operator/
operator.rs
