gremlin_client/structure/
map.rs

1use crate::error::GremlinError;
2use crate::structure::{Edge, GValue, Vertex};
3use crate::GremlinResult;
4use crate::Token;
5use std::collections::hash_map::IntoIter;
6use std::collections::{BTreeMap, HashMap};
7use std::convert::{TryFrom, TryInto};
8
9/// Represent a Map<[GKey](struct.GKey),[GValue](struct.GValue)> which has ability to allow for non-String keys.
10/// TinkerPop type [here](http://tinkerpop.apache.org/docs/current/dev/io/#_map)
11#[derive(Debug, PartialEq, Clone)]
12pub struct Map(HashMap<GKey, GValue>);
13
14impl Map {
15    pub(crate) fn empty() -> Map {
16        Map(HashMap::default())
17    }
18}
19
20impl From<HashMap<GKey, GValue>> for Map {
21    fn from(val: HashMap<GKey, GValue>) -> Self {
22        Map(val)
23    }
24}
25
26impl From<Map> for HashMap<GKey, GValue> {
27    fn from(map: Map) -> Self {
28        map.0
29    }
30}
31
32impl From<HashMap<String, GValue>> for Map {
33    fn from(val: HashMap<String, GValue>) -> Self {
34        let map = val.into_iter().map(|(k, v)| (GKey::String(k), v)).collect();
35        Map(map)
36    }
37}
38
39impl TryFrom<Map> for HashMap<String, GValue> {
40    type Error = GremlinError;
41
42    fn try_from(map: Map) -> Result<Self, Self::Error> {
43        map.into_iter()
44            .map(|(k, v)| Ok((k.try_into()?, v)))
45            .collect()
46    }
47}
48
49impl From<BTreeMap<String, GValue>> for Map {
50    fn from(val: BTreeMap<String, GValue>) -> Self {
51        let map = val.into_iter().map(|(k, v)| (GKey::String(k), v)).collect();
52        Map(map)
53    }
54}
55
56impl TryFrom<Map> for BTreeMap<String, GValue> {
57    type Error = GremlinError;
58
59    fn try_from(map: Map) -> Result<Self, Self::Error> {
60        map.into_iter()
61            .map(|(k, v)| Ok((k.try_into()?, v)))
62            .collect()
63    }
64}
65
66impl Map {
67    pub(crate) fn remove<T>(&mut self, key: T) -> Option<GValue>
68    where
69        T: Into<GKey>,
70    {
71        self.0.remove(&key.into())
72    }
73    /// Iterate all key-value pairs
74    pub fn iter(&self) -> impl Iterator<Item = (&GKey, &GValue)> {
75        self.0.iter()
76    }
77
78    ///Returns a reference to the value corresponding to the key.
79    pub fn get<T>(&self, key: T) -> Option<&GValue>
80    where
81        T: Into<GKey>,
82    {
83        self.0.get(&key.into())
84    }
85
86    ///Returns try_get and conversion
87    pub fn try_get<K, V>(&self, key: K) -> GremlinResult<V>
88    where
89        K: Into<GKey>,
90        V: std::convert::TryFrom<GValue, Error = GremlinError>,
91    {
92        self.0
93            .get(&key.into())
94            .cloned()
95            .or_else(|| Some(GValue::Null))
96            .map(V::try_from)
97            .ok_or_else(|| GremlinError::Cast(String::from("field not found")))?
98    }
99
100    /// Returns the number of elements in the map.
101    pub fn len(&self) -> usize {
102        self.0.len()
103    }
104
105    /// Returns true if the map contains no elements.
106    pub fn is_empty(&self) -> bool {
107        self.0.is_empty()
108    }
109}
110
111impl<T: Into<GKey>> std::ops::Index<T> for Map {
112    type Output = GValue;
113
114    fn index(&self, key: T) -> &GValue {
115        self.0.get(&key.into()).expect("no entry found for key")
116    }
117}
118
119impl IntoIterator for Map {
120    type Item = (GKey, GValue);
121    type IntoIter = IntoIter<GKey, GValue>;
122    fn into_iter(self) -> Self::IntoIter {
123        self.0.into_iter()
124    }
125}
126
127impl std::iter::FromIterator<(String, GValue)> for Map {
128    fn from_iter<I: IntoIterator<Item = (String, GValue)>>(iter: I) -> Self {
129        Map(iter
130            .into_iter()
131            .map(|(k, v)| (GKey::String(k), v))
132            .collect())
133    }
134}
135
136/// Possible key types in a [Map](struct.Map)
137#[allow(clippy::large_enum_variant)]
138#[derive(Debug, PartialEq, Clone, Eq, Hash)]
139pub enum GKey {
140    String(String),
141    Token(Token),
142    Vertex(Vertex),
143    Edge(Edge),
144}
145
146impl From<&str> for GKey {
147    fn from(val: &str) -> Self {
148        GKey::String(String::from(val))
149    }
150}
151
152impl From<String> for GKey {
153    fn from(val: String) -> Self {
154        GKey::String(val)
155    }
156}
157
158impl TryFrom<GKey> for String {
159    type Error = GremlinError;
160
161    fn try_from(k: GKey) -> Result<Self, Self::Error> {
162        if let GKey::String(s) = k {
163            Ok(s)
164        } else {
165            Err(GremlinError::Cast(String::from(format!(
166                "Cannot cast from {:?} to String",
167                k
168            ))))
169        }
170    }
171}
172
173impl From<&Vertex> for GKey {
174    fn from(val: &Vertex) -> Self {
175        GKey::Vertex(val.clone())
176    }
177}
178
179impl From<&Edge> for GKey {
180    fn from(val: &Edge) -> Self {
181        GKey::Edge(val.clone())
182    }
183}
gremlin_client/structure/map.rs

gremlin_client/structure/
map.rs
