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
|
// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ast
import (
"go/token"
"sort"
"strconv"
)
// SortImports sorts runs of consecutive import lines in import blocks in f.
func SortImports(fset *token.FileSet, f *File) {
for _, d := range f.Decls {
d, ok := d.(*GenDecl)
if !ok || d.Tok != token.IMPORT {
// Not an import declaration, so we're done.
// Imports are always first.
break
}
if d.Lparen == token.NoPos {
// Not a block: sorted by default.
continue
}
// Identify and sort runs of specs on successive lines.
i := 0
for j, s := range d.Specs {
if j > i && fset.Position(s.Pos()).Line > 1+fset.Position(d.Specs[j-1].End()).Line {
// j begins a new run. End this one.
sortSpecs(fset, f, d.Specs[i:j])
i = j
}
}
sortSpecs(fset, f, d.Specs[i:])
}
}
func importPath(s Spec) string {
t, err := strconv.Unquote(s.(*ImportSpec).Path.Value)
if err == nil {
return t
}
return ""
}
type posSpan struct {
Start token.Pos
End token.Pos
}
func sortSpecs(fset *token.FileSet, f *File, specs []Spec) {
// Avoid work if already sorted (also catches < 2 entries).
sorted := true
for i, s := range specs {
if i > 0 && importPath(specs[i-1]) > importPath(s) {
sorted = false
break
}
}
if sorted {
return
}
// Record positions for specs.
pos := make([]posSpan, len(specs))
for i, s := range specs {
pos[i] = posSpan{s.Pos(), s.End()}
}
// Identify comments in this range.
// Any comment from pos[0].Start to the final line counts.
lastLine := fset.Position(pos[len(pos)-1].End).Line
cstart := len(f.Comments)
cend := len(f.Comments)
for i, g := range f.Comments {
if g.Pos() < pos[0].Start {
continue
}
if i < cstart {
cstart = i
}
if fset.Position(g.End()).Line > lastLine {
cend = i
break
}
}
comments := f.Comments[cstart:cend]
// Assign each comment to the import spec preceding it.
importComment := map[*ImportSpec][]*CommentGroup{}
specIndex := 0
for _, g := range comments {
for specIndex+1 < len(specs) && pos[specIndex+1].Start <= g.Pos() {
specIndex++
}
s := specs[specIndex].(*ImportSpec)
importComment[s] = append(importComment[s], g)
}
// Sort the import specs by import path.
// Reassign the import paths to have the same position sequence.
// Reassign each comment to abut the end of its spec.
// Sort the comments by new position.
sort.Sort(byImportPath(specs))
for i, s := range specs {
s := s.(*ImportSpec)
if s.Name != nil {
s.Name.NamePos = pos[i].Start
}
s.Path.ValuePos = pos[i].Start
s.EndPos = pos[i].End
for _, g := range importComment[s] {
for _, c := range g.List {
c.Slash = pos[i].End
}
}
}
sort.Sort(byCommentPos(comments))
}
type byImportPath []Spec // slice of *ImportSpec
func (x byImportPath) Len() int { return len(x) }
func (x byImportPath) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byImportPath) Less(i, j int) bool { return importPath(x[i]) < importPath(x[j]) }
type byCommentPos []*CommentGroup
func (x byCommentPos) Len() int { return len(x) }
func (x byCommentPos) Swap(i, j int) { x[i], x[j] = x[j], x[i] }
func (x byCommentPos) Less(i, j int) bool { return x[i].Pos() < x[j].Pos() }
|