xi-rope 0.3.0

A generic rope data structure built on top of B-Trees.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130

// Copyright 2019 The xi-editor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::fmt;
use std::str::FromStr;

use serde::de::{self, Deserialize, Deserializer, Visitor};
use serde::ser::{Serialize, SerializeStruct, SerializeTupleVariant, Serializer};

use crate::tree::Node;
use crate::{Delta, DeltaElement, Rope, RopeInfo};

impl Serialize for Rope {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        serializer.serialize_str(&String::from(self))
    }
}

impl<'de> Deserialize<'de> for Rope {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        deserializer.deserialize_str(RopeVisitor)
    }
}

struct RopeVisitor;

impl<'de> Visitor<'de> for RopeVisitor {
    type Value = Rope;

    fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "a string")
    }

    fn visit_str<E>(self, s: &str) -> Result<Self::Value, E>
    where
        E: de::Error,
    {
        Rope::from_str(s).map_err(|_| de::Error::invalid_value(de::Unexpected::Str(s), &self))
    }
}

impl Serialize for DeltaElement<RopeInfo> {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        match *self {
            DeltaElement::Copy(ref start, ref end) => {
                let mut el = serializer.serialize_tuple_variant("DeltaElement", 0, "copy", 2)?;
                el.serialize_field(start)?;
                el.serialize_field(end)?;
                el.end()
            }
            DeltaElement::Insert(ref node) => {
                serializer.serialize_newtype_variant("DeltaElement", 1, "insert", node)
            }
        }
    }
}

impl Serialize for Delta<RopeInfo> {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        let mut delta = serializer.serialize_struct("Delta", 2)?;
        delta.serialize_field("els", &self.els)?;
        delta.serialize_field("base_len", &self.base_len)?;
        delta.end()
    }
}

impl<'de> Deserialize<'de> for Delta<RopeInfo> {
    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
    where
        D: Deserializer<'de>,
    {
        // NOTE: we derive to an interim representation and then convert
        // that into our actual target.
        #[derive(Serialize, Deserialize)]
        #[serde(rename_all = "snake_case")]
        enum RopeDeltaElement_ {
            Copy(usize, usize),
            Insert(Node<RopeInfo>),
        }

        #[derive(Serialize, Deserialize)]
        struct RopeDelta_ {
            els: Vec<RopeDeltaElement_>,
            base_len: usize,
        }

        impl From<RopeDeltaElement_> for DeltaElement<RopeInfo> {
            fn from(elem: RopeDeltaElement_) -> DeltaElement<RopeInfo> {
                match elem {
                    RopeDeltaElement_::Copy(start, end) => DeltaElement::Copy(start, end),
                    RopeDeltaElement_::Insert(rope) => DeltaElement::Insert(rope),
                }
            }
        }

        impl From<RopeDelta_> for Delta<RopeInfo> {
            fn from(mut delta: RopeDelta_) -> Delta<RopeInfo> {
                Delta {
                    els: delta.els.drain(..).map(DeltaElement::from).collect(),
                    base_len: delta.base_len,
                }
            }
        }
        let d = RopeDelta_::deserialize(deserializer)?;
        Ok(Delta::from(d))
    }
}