summaryrefslogtreecommitdiff
path: root/src/line_modification.cc
blob: da3ee87f0c447fbfc5e5855680448ecb5b0a8937 (plain)
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
#include "line_modification.hh"

#include "buffer.hh"
#include "unit_tests.hh"

namespace Kakoune
{

static LineModification make_line_modif(const Buffer::Change& change)
{
    LineCount num_added = 0, num_removed = 0;
    if (change.type == Buffer::Change::Insert)
        num_added = change.end.line - change.begin.line;
    else
        num_removed = change.end.line - change.begin.line;
    // modified a line
    if ((change.begin.column != 0 or change.end.column != 0))
    {
        ++num_removed;
        ++num_added;
    }
    return { change.begin.line, change.begin.line, num_removed, num_added };
}

Vector<LineModification> compute_line_modifications(const Buffer& buffer, size_t timestamp)
{
    Vector<LineModification> res;
    for (auto& buf_change : buffer.changes_since(timestamp))
    {
        auto change = make_line_modif(buf_change);

        auto pos = std::upper_bound(res.begin(), res.end(), change.new_line,
                                    [](const LineCount& l, const LineModification& c)
                                    { return l < c.new_line; });

        if (pos != res.begin())
        {
            auto& prev = *(pos-1);
            if (change.new_line <= prev.new_line + prev.num_added)
            {
                --pos;
                const LineCount removed_from_previously_added_by_pos =
                    clamp(pos->new_line + pos->num_added - change.new_line,
                          0_line, std::min(pos->num_added, change.num_removed));

                pos->num_removed += change.num_removed - removed_from_previously_added_by_pos;
                pos->num_added += change.num_added - removed_from_previously_added_by_pos;
            }
            else
            {
                change.old_line -= prev.diff();
                pos = res.insert(pos, change);
            }
        }
        else
            pos = res.insert(pos, change);

        auto next = pos + 1;
        auto diff = buf_change.end.line - buf_change.begin.line;
        if (buf_change.type == Buffer::Change::Erase)
        {
            auto delend = std::upper_bound(next, res.end(), change.new_line + change.num_removed,
                                           [](const LineCount& l, const LineModification& c)
                                           { return l < c.new_line; });

            for (auto it = next; it != delend; ++it)
            {
                const LineCount removed_from_previously_added_by_it =
                    std::min(it->num_added, change.new_line + change.num_removed - it->new_line);

                pos->num_removed += it->num_removed - removed_from_previously_added_by_it;
                pos->num_added += it->num_added - removed_from_previously_added_by_it;
            }
            next = res.erase(next, delend);

            if (diff != 0)
            {
                for (auto it = next; it != res.end(); ++it)
                    it->new_line -= diff;
            }
        }
        else if (diff != 0)
        {
            for (auto it = next; it != res.end(); ++it)
                it->new_line += diff;
        }
    }
    return res;
}

bool operator==(const LineModification& lhs, const LineModification& rhs)
{
    return std::tie(lhs.old_line, lhs.new_line, lhs.num_removed, lhs.num_added) ==
           std::tie(rhs.old_line, rhs.new_line, rhs.num_removed, rhs.num_added);
}

UnitTest test_line_modifications{[]()
{
    {
        Buffer buffer("test", Buffer::Flags::None, "line 1\nline 2\n");
        auto ts = buffer.timestamp();
        buffer.erase({1, 0}, {2, 0});

        auto modifs = compute_line_modifications(buffer, ts);
        kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 1, 1, 1, 0 });
    }

    {
        Buffer buffer("test", Buffer::Flags::None, "line 1\nline 2\n");
        auto ts = buffer.timestamp();
        buffer.insert({2, 0}, "line 3");

        auto modifs = compute_line_modifications(buffer, ts);
        kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 2, 2, 0, 1 });
    }

    {
        Buffer buffer("test", Buffer::Flags::None, "line 1\nline 2\nline 3\n");

        auto ts = buffer.timestamp();
        buffer.insert({1, 4}, "hoho\nhehe");
        buffer.erase({0, 0}, {1, 0});

        auto modifs = compute_line_modifications(buffer, ts);
        kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 0, 0, 2, 2 });
    }

    {
        Buffer buffer("test", Buffer::Flags::None, "line 1\nline 2\nline 3\nline 4\n");

        auto ts = buffer.timestamp();
        buffer.erase({0,0}, {3,0});
        buffer.insert({1,0}, "newline 1\nnewline 2\nnewline 3\n");
        buffer.erase({0,0}, {1,0});
        {
            auto modifs = compute_line_modifications(buffer, ts);
            kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 0, 0, 4, 3 });
        }
        buffer.insert({3,0}, "newline 4\n");

        {
            auto modifs = compute_line_modifications(buffer, ts);
            kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 0, 0, 4, 4 });
        }
    }

    {
        Buffer buffer("test", Buffer::Flags::None, "line 1\n");
        auto ts = buffer.timestamp();
        buffer.insert({0,0}, "n");
        buffer.insert({0,1}, "e");
        buffer.insert({0,2}, "w");
        auto modifs = compute_line_modifications(buffer, ts);
        kak_assert(modifs.size() == 1 and modifs[0] == LineModification{ 0, 0, 1, 1 });
    }
}};

}