Repository navigation
Expand file tree
/
Copy pathdoc.go
More file actions
425 lines (309 loc) · 8.97 KB
/
Copy pathdoc.go
File metadata and controls
425 lines (309 loc) · 8.97 KB
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
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
package simple
import "honnef.co/go/tools/lint"
var Docs = map[string]*lint.Documentation{
"S1000": &lint.Documentation{
Title: `Use plain channel send or receive instead of single-case select`,
Text: `Select statements with a single case can be replaced with a simple
send or receive.
Before:
select {
case x := <-ch:
fmt.Println(x)
}
After:
x := <-ch
fmt.Println(x)`,
Since: "2017.1",
},
"S1001": &lint.Documentation{
Title: `Replace for loop with call to copy`,
Text: `Use copy() for copying elements from one slice to another.
Before:
for i, x := range src {
dst[i] = x
}
After:
copy(dst, src)`,
Since: "2017.1",
},
"S1002": &lint.Documentation{
Title: `Omit comparison with boolean constant`,
Text: `Before:
if x == true {}
After:
if x {}`,
Since: "2017.1",
},
"S1003": &lint.Documentation{
Title: `Replace call to strings.Index with strings.Contains`,
Text: `Before:
if strings.Index(x, y) != -1 {}
After:
if strings.Contains(x, y) {}`,
Since: "2017.1",
},
"S1004": &lint.Documentation{
Title: `Replace call to bytes.Compare with bytes.Equal`,
Text: `Before:
if bytes.Compare(x, y) == 0 {}
After:
if bytes.Equal(x, y) {}`,
Since: "2017.1",
},
"S1005": &lint.Documentation{
Title: `Drop unnecessary use of the blank identifier`,
Text: `In many cases, assigning to the blank identifier is unnecessary.
Before:
for _ = range s {}
x, _ = someMap[key]
_ = <-ch
After:
for range s{}
x = someMap[key]
<-ch`,
Since: "2017.1",
},
"S1006": &lint.Documentation{
Title: `Use for { ... } for infinite loops`,
Text: `For infinite loops, using for { ... } is the most idiomatic choice.`,
Since: "2017.1",
},
"S1007": &lint.Documentation{
Title: `Simplify regular expression by using raw string literal`,
Text: `Raw string literals use ` + "`" + ` instead of " and do not support
any escape sequences. This means that the backslash (\) can be used
freely, without the need of escaping.
Since regular expressions have their own escape sequences, raw strings
can improve their readability.
Before:
regexp.Compile("\\A(\\w+) profile: total \\d+\\n\\z")
After:
regexp.Compile(` + "`" + `\A(\w+) profile: total \d+\n\z` + "`" + `)`,
Since: "2017.1",
},
"S1008": &lint.Documentation{
Title: `Simplify returning boolean expression`,
Text: `Before:
if <expr> {
return true
}
return false
After:
return <expr>`,
Since: "2017.1",
},
"S1009": &lint.Documentation{
Title: `Omit redundant nil check on slices`,
Text: `The len function is defined for all slices, even nil ones, which have
a length of zero. It is not necessary to check if a slice is not nil
before checking that its length is not zero.
Before:
if x != nil && len(x) != 0 {}
After:
if len(x) != 0 {}`,
Since: "2017.1",
},
"S1010": &lint.Documentation{
Title: `Omit default slice index`,
Text: `When slicing, the second index defaults to the length of the value,
making s[n:len(s)] and s[n:] equivalent.`,
Since: "2017.1",
},
"S1011": &lint.Documentation{
Title: `Use a single append to concatenate two slices`,
Text: `Before:
for _, e := range y {
x = append(x, e)
}
After:
x = append(x, y...)`,
Since: "2017.1",
},
"S1012": &lint.Documentation{
Title: `Replace time.Now().Sub(x) with time.Since(x)`,
Text: `The time.Since helper has the same effect as using time.Now().Sub(x)
but is easier to read.
Before:
time.Now().Sub(x)
After:
time.Since(x)`,
Since: "2017.1",
},
"S1016": &lint.Documentation{
Title: `Use a type conversion instead of manually copying struct fields`,
Text: `Two struct types with identical fields can be converted between each
other. In older versions of Go, the fields had to have identical
struct tags. Since Go 1.8, however, struct tags are ignored during
conversions. It is thus not necessary to manually copy every field
individually.
Before:
var x T1
y := T2{
Field1: x.Field1,
Field2: x.Field2,
}
After:
var x T1
y := T2(x)`,
Since: "2017.1",
},
"S1017": &lint.Documentation{
Title: `Replace manual trimming with strings.TrimPrefix`,
Text: `Instead of using strings.HasPrefix and manual slicing, use the
strings.TrimPrefix function. If the string doesn't start with the
prefix, the original string will be returned. Using strings.TrimPrefix
reduces complexity, and avoids common bugs, such as off-by-one
mistakes.
Before:
if strings.HasPrefix(str, prefix) {
str = str[len(prefix):]
}
After:
str = strings.TrimPrefix(str, prefix)`,
Since: "2017.1",
},
"S1018": &lint.Documentation{
Title: `Use copy for sliding elements`,
Text: `copy() permits using the same source and destination slice, even with
overlapping ranges. This makes it ideal for sliding elements in a
slice.
Before:
for i := 0; i < n; i++ {
bs[i] = bs[offset+i]
}
After:
copy(bs[:n], bs[offset:])`,
Since: "2017.1",
},
"S1019": &lint.Documentation{
Title: `Simplify make call by omitting redundant arguments`,
Text: `The make function has default values for the length and capacity
arguments. For channels and maps, the length defaults to zero.
Additionally, for slices the capacity defaults to the length.`,
Since: "2017.1",
},
"S1020": &lint.Documentation{
Title: `Omit redundant nil check in type assertion`,
Text: `Before:
if _, ok := i.(T); ok && i != nil {}
After:
if _, ok := i.(T); ok {}`,
Since: "2017.1",
},
"S1021": &lint.Documentation{
Title: `Merge variable declaration and assignment`,
Text: `Before:
var x uint
x = 1
After:
var x uint = 1`,
Since: "2017.1",
},
"S1023": &lint.Documentation{
Title: `Omit redundant control flow`,
Text: `Functions that have no return value do not need a return statement as
the final statement of the function.
Switches in Go do not have automatic fallthrough, unlike languages
like C. It is not necessary to have a break statement as the final
statement in a case block.`,
Since: "2017.1",
},
"S1024": &lint.Documentation{
Title: `Replace x.Sub(time.Now()) with time.Until(x)`,
Text: `The time.Until helper has the same effect as using x.Sub(time.Now())
but is easier to read.
Before:
x.Sub(time.Now())
After:
time.Until(x)`,
Since: "2017.1",
},
"S1025": &lint.Documentation{
Title: `Don't use fmt.Sprintf("%s", x) unnecessarily`,
Text: `In many instances, there are easier and more efficient ways of getting
a value's string representation. Whenever a value's underlying type is
a string already, or the type has a String method, they should be used
directly.
Given the following shared definitions
type T1 string
type T2 int
func (T2) String() string { return "Hello, world" }
var x string
var y T1
var z T2
we can simplify the following
fmt.Sprintf("%s", x)
fmt.Sprintf("%s", y)
fmt.Sprintf("%s", z)
to
x
string(y)
z.String()`,
Since: "2017.1",
},
"S1028": &lint.Documentation{
Title: `Simplify error construction with fmt.Errorf`,
Text: `Before:
errors.New(fmt.Sprintf(...))
After:
fmt.Errorf(...)`,
Since: "2017.1",
},
"S1029": &lint.Documentation{
Title: `Range over the string directly`,
Text: `Ranging over a string will yield byte offsets and runes. If the offset
isn't used, this is functionally equivalent to converting the string
to a slice of runes and ranging over that. Ranging directly over the
string will be more performant, however, as it avoids allocating a new
slice, the size of which depends on the length of the string.
Before:
for _, r := range []rune(s) {}
After:
for _, r := range s {}`,
Since: "2017.1",
},
"S1030": &lint.Documentation{
Title: `Use bytes.Buffer.String or bytes.Buffer.Bytes`,
Text: `bytes.Buffer has both a String and a Bytes method. It is never
necessary to use string(buf.Bytes()) or []byte(buf.String()) – simply
use the other method.`,
Since: "2017.1",
},
"S1031": &lint.Documentation{
Title: `Omit redundant nil check around loop`,
Text: `You can use range on nil slices and maps, the loop will simply never
execute. This makes an additional nil check around the loop
unnecessary.
Before:
if s != nil {
for _, x := range s {
...
}
}
After:
for _, x := range s {
...
}`,
Since: "2017.1",
},
"S1032": &lint.Documentation{
Title: `Use sort.Ints(x), sort.Float64s(x), and sort.Strings(x)`,
Text: `The sort.Ints, sort.Float64s and sort.Strings functions are easier to
read than sort.Sort(sort.IntSlice(x)), sort.Sort(sort.Float64Slice(x))
and sort.Sort(sort.StringSlice(x)).
Before:
sort.Sort(sort.StringSlice(x))
After:
sort.Strings(x)`,
Since: "2019.1",
},
"S1033": &lint.Documentation{
Title: `Unnecessary guard around call to delete`,
Text: `Calling delete on a nil map is a no-op.`,
Since: "2019.2",
},
"S1034": &lint.Documentation{
Title: `Use result of type assertion to simplify cases`,
Since: "2019.2",
},
}