solomon_gremlin/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 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().map(|(k, v)| Ok((k.try_into()?, v))).collect()
44	}
45}
46
47impl From<BTreeMap<String, GValue>> for Map {
48	fn from(val: BTreeMap<String, GValue>) -> Self {
49		let map = val.into_iter().map(|(k, v)| (GKey::String(k), v)).collect();
50		Map(map)
51	}
52}
53
54impl TryFrom<Map> for BTreeMap<String, GValue> {
55	type Error = GremlinError;
56
57	fn try_from(map: Map) -> Result<Self, Self::Error> {
58		map.into_iter().map(|(k, v)| Ok((k.try_into()?, v))).collect()
59	}
60}
61
62impl Map {
63	pub fn remove<T>(&mut self, key: T) -> Option<GValue>
64	where
65		T: Into<GKey>,
66	{
67		self.0.remove(&key.into())
68	}
69	/// Iterate all key-value pairs
70	pub fn iter(&self) -> impl Iterator<Item = (&GKey, &GValue)> {
71		self.0.iter()
72	}
73
74	///Returns a reference to the value corresponding to the key.
75	pub fn get<T>(&self, key: T) -> Option<&GValue>
76	where
77		T: Into<GKey>,
78	{
79		self.0.get(&key.into())
80	}
81
82	///Returns try_get and conversion
83	pub fn try_get<K, V>(&self, key: K) -> GremlinResult<V>
84	where
85		K: Into<GKey>,
86		V: std::convert::TryFrom<GValue, Error = GremlinError>,
87	{
88		self.0
89			.get(&key.into())
90			.cloned()
91			.or(Some(GValue::Null))
92			.map(V::try_from)
93			.ok_or_else(|| GremlinError::Cast(String::from("field not found")))?
94	}
95
96	/// Returns the number of elements in the map.
97	pub fn len(&self) -> usize {
98		self.0.len()
99	}
100
101	/// Returns true if the map contains no elements.
102	pub fn is_empty(&self) -> bool {
103		self.0.is_empty()
104	}
105}
106
107impl<T: Into<GKey>> std::ops::Index<T> for Map {
108	type Output = GValue;
109
110	fn index(&self, key: T) -> &GValue {
111		self.0.get(&key.into()).expect("no entry found for key")
112	}
113}
114
115impl IntoIterator for Map {
116	type Item = (GKey, GValue);
117	type IntoIter = IntoIter<GKey, GValue>;
118	fn into_iter(self) -> Self::IntoIter {
119		self.0.into_iter()
120	}
121}
122
123impl std::iter::FromIterator<(String, GValue)> for Map {
124	fn from_iter<I: IntoIterator<Item = (String, GValue)>>(iter: I) -> Self {
125		Map(iter.into_iter().map(|(k, v)| (GKey::String(k), v)).collect())
126	}
127}
128
129/// Possible key types in a [Map](struct.Map)
130#[allow(clippy::large_enum_variant)]
131#[derive(Debug, PartialEq, Clone, Eq, Hash)]
132pub enum GKey {
133	String(String),
134	Token(Token),
135	Vertex(Vertex),
136	Edge(Edge),
137}
138
139impl From<&str> for GKey {
140	fn from(val: &str) -> Self {
141		GKey::String(String::from(val))
142	}
143}
144
145impl From<String> for GKey {
146	fn from(val: String) -> Self {
147		GKey::String(val)
148	}
149}
150
151impl TryFrom<GKey> for String {
152	type Error = GremlinError;
153
154	fn try_from(k: GKey) -> Result<Self, Self::Error> {
155		if let GKey::String(s) = k {
156			Ok(s)
157		} else {
158			Err(GremlinError::Cast(format!("Cannot cast from {:?} to String", k)))
159		}
160	}
161}
162
163impl From<&Vertex> for GKey {
164	fn from(val: &Vertex) -> Self {
165		GKey::Vertex(val.clone())
166	}
167}
168
169impl From<&Edge> for GKey {
170	fn from(val: &Edge) -> Self {
171		GKey::Edge(val.clone())
172	}
173}
solomon_gremlin/structure/map.rs

solomon_gremlin/structure/
map.rs
