teo_parser/value/
index.rs

1use std::ops;
2use indexmap::IndexMap;
3use super::value::Value;
4
5// Code from this file is inspired from serde json
6// https://github.com/serde-rs/json/blob/master/src/value/index.rs
7
8pub trait Index {
9    fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value>;
10    fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value>;
11    fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value;
12}
13
14impl Index for usize {
15
16    fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> {
17        match v {
18            Value::Array(vec) => vec.get(*self),
19            Value::Tuple(vec) => vec.get(*self),
20            _ => None,
21        }
22    }
23
24    fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> {
25        match v {
26            Value::Array(vec) => vec.get_mut(*self),
27            Value::Tuple(vec) => vec.get_mut(*self),
28            _ => None,
29        }
30    }
31
32    fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value {
33        match v {
34            Value::Array(vec) => {
35                let len = vec.len();
36                vec.get_mut(*self).unwrap_or_else(|| {
37                    panic!(
38                        "cannot access index {} of parser value array of length {}",
39                        self, len
40                    )
41                })
42            },
43            Value::Tuple(vec) => {
44                let len = vec.len();
45                vec.get_mut(*self).unwrap_or_else(|| {
46                    panic!(
47                        "cannot access index {} of parser value tuple of length {}",
48                        self, len
49                    )
50                })
51            },
52            _ => panic!("cannot access index {} of parser value {}", self, v),
53        }
54    }
55}
56
57impl Index for str {
58
59    fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> {
60        match v {
61            Value::Dictionary(map) => map.get(self),
62            _ => None,
63        }
64    }
65
66    fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> {
67        match v {
68            Value::Dictionary(map) => map.get_mut(self),
69            _ => None,
70        }
71    }
72
73    fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value {
74        if let Value::Null = v {
75            *v = Value::Dictionary(IndexMap::new());
76        }
77        match v {
78            Value::Dictionary(map) => map.entry(self.to_owned()).or_insert(Value::Null),
79            _ => panic!("cannot access key {:?} in parser value {}", self, v),
80        }
81    }
82}
83
84impl Index for String {
85
86    fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> {
87        self[..].index_into(v)
88    }
89
90    fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> {
91        self[..].index_into_mut(v)
92    }
93
94    fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value {
95        self[..].index_or_insert(v)
96    }
97}
98
99impl<'a, T> Index for &'a T where T: ?Sized + Index, {
100
101    fn index_into<'v>(&self, v: &'v Value) -> Option<&'v Value> {
102        (**self).index_into(v)
103    }
104
105    fn index_into_mut<'v>(&self, v: &'v mut Value) -> Option<&'v mut Value> {
106        (**self).index_into_mut(v)
107    }
108
109    fn index_or_insert<'v>(&self, v: &'v mut Value) -> &'v mut Value {
110        (**self).index_or_insert(v)
111    }
112}
113
114impl<I> ops::Index<I> for Value where I: Index {
115
116    type Output = Value;
117
118    fn index(&self, index: I) -> &Value {
119        static NULL: Value = Value::Null;
120        index.index_into(self).unwrap_or(&NULL)
121    }
122}
123
124impl<I> ops::IndexMut<I> for Value where I: Index {
125
126    fn index_mut(&mut self, index: I) -> &mut Value {
127        index.index_or_insert(self)
128    }
129}
teo_parser/value/index.rs

teo_parser/value/
index.rs
