summaryrefslogtreecommitdiff
path: root/doc/devel/release.html
blob: d6de1d71ce103e9ffbeb3a5da5c905b8af6d607d (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
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
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
<!-- Release History -->

<p>This page summarizes the changes between official stable releases of Go.
Between releases we issue less stable
<a href="http://blog.golang.org/2011/03/go-becomes-more-stable.html">weekly snapshots</a>.
The <a href="weekly.html">weekly snapshot history</a> contains more detail,
and the <a href="http://code.google.com/p/go/source/list">Mercurial change log</a>
has full details.</p>

<p>To update to a specific release, use:</p>

<pre>
hg pull
hg update release.r<i>NN</i>
</pre>

<h2 id="r60">r60 (released 2011/09/07)</h2>

<p>
The r60 release corresponds to 
<code><a href="weekly.html#2011-08-17">weekly.2011-08-17</a></code>.
This section highlights the most significant changes in this release.
For a more detailed summary, see the
<a href="weekly.html#2011-08-17">weekly release notes</a>.
For complete information, see the
<a href="http://code.google.com/p/go/source/list?r=release-branch.r60">Mercurial change list</a>.
</p>

<h3 id="r60.lang">Language</h3>

<p>
An "else" block is now required to have braces except if the body of the "else"
is another "if". Since gofmt always puts those braces in anyway,
gofmt-formatted programs will not be affected.
To fix other programs, run gofmt.
</p>

<h3 id="r60.pkg">Packages</h3>

<p>
<a href="/pkg/http/">Package http</a>'s URL parsing and query escaping code
(such as <code>ParseURL</code> and <code>URLEscape</code>) has been moved to
the new <a href="/pkg/url/">url package</a>, with several simplifications to
the names. Client code can be updated automatically with gofix.
</p>

<p>
<a href="/pkg/image/">Package image</a> has had significant changes made to the
<code>Pix</code> field of struct types such as
<a href="/pkg/image/#RGBA">image.RGBA</a> and
<a href="/pkg/image/#NRGBA">image.NRGBA</a>.
The <a href="/pkg/image/#Image">image.Image</a> interface type has not changed,
though, and you should not need to change your code if you don't explicitly
refer to <code>Pix</code> fields. For example, if you decode a number of images
using the <a href="/pkg/image/jpeg/">image/jpeg</a> package, compose them using
<a href="/pkg/image/draw/">image/draw</a>, and then encode the result using
<a href="/pkg/img/png">image/png</a>, then your code should still work as
before.
If your code <i>does</i> refer to <code>Pix</code> fields see the 
<a href="/doc/devel/weekly.html#2011-07-19">weekly.2011-07-19</a>
snapshot notes for how to update your code.
</p>

<p>
<a href="/pkg/template/">Package template</a> has been replaced with a new
templating package (formerly <code>exp/template</code>). The original template
package is still available as <a href="/pkg/old/template/">old/template</a>.
The <code>old/template</code> package is deprecated and will be removed.
The Go tree has been updated to use the new template package. We encourage
users of the old template package to switch to the new one. Code that uses
<code>template</code> or <code>exp/template</code> will need to change its
import lines to <code>"old/template"</code> or <code>"template"</code>,
respectively.
</p>

<h3 id="r60.cmd">Tools</h3>

<p>
<a href="/cmd/goinstall/">Goinstall</a> now uses a new tag selection scheme.
When downloading or updating, goinstall looks for a tag or branch with the
<code>"go."</code> prefix that corresponds to the local Go version. For Go
<code>release.r58</code> it looks for <code>go.r58</code>. For
<code>weekly.2011-06-03</code> it looks for <code>go.weekly.2011-06-03</code>.
If the specific <code>go.X</code> tag or branch is not found, it chooses the
closest earlier version. If an appropriate tag or branch is found, goinstall
uses that version of the code. Otherwise it uses the default version selected
by the version control system. Library authors are encouraged to use the
appropriate tag or branch names in their repositories to make their libraries
more accessible.
</p>

<h3 id="r60.minor">Minor revisions</h3>

<p>
r60.1 includes a 
<a href="http://code.google.com/p/go/source/detail?r=1824581bf62d">linker
fix</a>, a pair of
<a href="http://code.google.com/p/go/source/detail?r=9ef4429c2c64">goplay</a>
<a href="http://code.google.com/p/go/source/detail?r=d42ed8c3098e">fixes</a>,
and a <code>json</code> package
<a href="http://code.google.com/p/go/source/detail?r=d5e97874fe84">fix</a> and
a new
<a href="http://code.google.com/p/go/source/detail?r=4f0e6269213f">struct tag
option</a>.
</p>

<p>
r60.2
<a href="http://code.google.com/p/go/source/detail?r=ff19536042ac">fixes</a>
a memory leak involving maps.
</p>

<h2 id="r59">r59 (released 2011/08/01)</h2>

<p>
The r59 release corresponds to 
<code><a href="weekly.html#2011-07-07">weekly.2011-07-07</a></code>.
This section highlights the most significant changes in this release.
For a more detailed summary, see the
<a href="weekly.html#2011-07-07">weekly release notes</a>.
For complete information, see the
<a href="http://code.google.com/p/go/source/list?r=release-branch.r59">Mercurial change list</a>.
</p>

<h3 id="r59.lang">Language</h3>

<p>
This release includes a language change that restricts the use of
<code>goto</code>.  In essence, a <code>goto</code> statement outside a block
cannot jump to a label inside that block. Your code may require changes if it
uses <code>goto</code>.
See <a href="http://code.google.com/p/go/source/detail?r=dc6d3cf9279d">this
changeset</a> for how the new rule affected the Go tree.
</p>

<h3 id="r59.pkg">Packages</h3>

<p>
As usual, <a href="/cmd/gofix/">gofix</a> will handle the bulk of the rewrites
necessary for these changes to package APIs.
</p>

<p>
<a href="/pkg/http">Package http</a> has a new
<a href="/pkg/http/#FileSystem">FileSystem</a> interface that provides access
to files. The <a href="/pkg/http/#FileServer">FileServer</a> helper now takes a
<code>FileSystem</code> argument instead of an explicit file system root. By
implementing your own <code>FileSystem</code> you can use the
<code>FileServer</code> to serve arbitrary data.
</p>

<p>
<a href="/pkg/os/">Package os</a>'s <code>ErrorString</code> type has been
hidden. Most uses of <code>os.ErrorString</code> can be replaced with
<a href="/pkg/os/#NewError">os.NewError</a>.
</p>

<p>
<a href="/pkg/reflect/">Package reflect</a> supports a new struct tag scheme
that enables sharing of struct tags between multiple packages.
In this scheme, the tags must be of the form:
</p>
<pre>
	`key:"value" key2:"value2"`
</pre>
<p>
The <a href="/pkg/reflect/#StructField">StructField</a> type's Tag field now
has type <a href="/pkg/reflect/#StructTag">StructTag</a>, which has a
<code>Get</code> method. Clients of <a href="/pkg/json">json</a> and
<a href="/pkg/xml">xml</a> will need to be updated. Code that says
</p>
<pre>
	type T struct {
		X int "name"
	}
</pre>
<p>
should become
</p>
<pre>
	type T struct {
		X int `json:"name"`  // or `xml:"name"`
	}
</pre>
<p>
Use <a href="/cmd/govet/">govet</a> to identify struct tags that need to be
changed to use the new syntax.
</p>

<p>
<a href="/pkg/sort/">Package sort</a>'s <code>IntArray</code> type has been
renamed to <a href="/pkg/sort/#IntSlice">IntSlice</a>, and similarly for
<a href="/pkg/sort/#Float64Slice">Float64Slice</a> and
<a href="/pkg/sort/#StringSlice">StringSlice</a>.
</p>

<p>
<a href="/pkg/strings/">Package strings</a>'s <code>Split</code> function has
itself been split into <a href="/pkg/strings/#Split">Split</a> and
<a href="/pkg/strings/#SplitN">SplitN</a>.
<code>SplitN</code> is the same as the old <code>Split</code>.
The new <code>Split</code> is equivalent to <code>SplitN</code> with a final
argument of -1.
</p>

<a href="/pkg/image/draw/">Package image/draw</a>'s
<a href="/pkg/image/draw/#Draw">Draw</a> function now takes an additional
argument, a compositing operator.
If in doubt, use <a href="/pkg/image/draw/#Op">draw.Over</a>.
</p>

<h3 id="r59.cmd">Tools</h3>

<p>
<a href="/cmd/goinstall/">Goinstall</a> now installs packages and commands from
arbitrary remote repositories (not just Google Code, Github, and so on).
See the <a href="/cmd/goinstall/">goinstall documentation</a> for details.
</p>

<h2 id="r58">r58 (released 2011/06/29)</h2>

<p>
The r58 release corresponds to 
<code><a href="weekly.html#2011-06-09">weekly.2011-06-09</a></code>
with additional bug fixes.
This section highlights the most significant changes in this release.
For a more detailed summary, see the
<a href="weekly.html#2011-06-09">weekly release notes</a>.
For complete information, see the
<a href="http://code.google.com/p/go/source/list?r=release-branch.r58">Mercurial change list</a>.
</p>

<h3 id="r58.lang">Language</h3>

<p>
This release fixes a <a href="http://code.google.com/p/go/source/detail?r=b720749486e1">use of uninitialized memory in programs that misuse <code>goto</code></a>.
</p>

<h3 id="r58.pkg">Packages</h3>

<p>
As usual, <a href="/cmd/gofix/">gofix</a> will handle the bulk of the rewrites
necessary for these changes to package APIs.
</p>

<p>
<a href="/pkg/http/">Package http</a> drops the <code>finalURL</code> return
value from the <a href="/pkg/http/#Client.Get">Client.Get</a> method. The value
is now available via the new <code>Request</code> field on <a
href="/pkg/http/#Response">http.Response</a>.
Most instances of the type map[string][]string in have been
replaced with the new <a href="/pkg/http/#Values">Values</a> type.
</p>

<p>
<a href="/pkg/exec/">Package exec</a> has been redesigned with a more
convenient and succinct API.
</p>

<p>
<a href="/pkg/strconv/">Package strconv</a>'s <a href="/pkg/strconv/#Quote">Quote</a>
function now escapes only those Unicode code points not classified as printable
by <a href="/pkg/unicode/#IsPrint">unicode.IsPrint</a>.
Previously Quote would escape all non-ASCII characters.
This also affects the <a href="/pkg/fmt/">fmt</a> package's <code>"%q"</code>
formatting directive. The previous quoting behavior is still available via
strconv's new <a href="/pkg/strconv/#QuoteToASCII">QuoteToASCII</a> function.   
</p>

<p>
<a href="/pkg/os/signal/">Package os/signal</a>'s
<a href="/pkg/os/#Signal">Signal</a> and 
<a href="/pkg/os/#UnixSignal">UnixSignal</a> types have been moved to the
<a href="/pkg/os/">os</a> package.
</p>

<p>
<a href="/pkg/image/draw/">Package image/draw</a> is the new name for
<code>exp/draw</code>. The GUI-related code from <code>exp/draw</code> is now
located in the <a href="/pkg/exp/gui/">exp/gui</a> package.
</p>

<h3 id="r58.cmd">Tools</h3>

<p>
<a href="/cmd/goinstall/">Goinstall</a> now observes the GOPATH environment
variable to build and install your own code and external libraries outside of
the Go tree (and avoid writing Makefiles).
</p>


<h3 id="r58.minor">Minor revisions</h3>

<p>r58.1 adds 
<a href="http://code.google.com/p/go/source/detail?r=293c25943586">build</a> and
<a href="http://code.google.com/p/go/source/detail?r=bf17e96b6582">runtime</a>
changes to make Go run on OS X 10.7 Lion.
</p>

<h2 id="r57">r57 (released 2011/05/03)</h2>

<p>
The r57 release corresponds to 
<code><a href="weekly.html#2011-04-27">weekly.2011-04-27</a></code>
with additional bug fixes.
This section highlights the most significant changes in this release.
For a more detailed summary, see the
<a href="weekly.html#2011-04-27">weekly release notes</a>.
For complete information, see the
<a href="http://code.google.com/p/go/source/list?r=release-branch.r57">Mercurial change list</a>.
</p>

<p>The new <a href="/cmd/gofix">gofix</a> tool finds Go programs that use old APIs and rewrites them to use
newer ones.  After you update to a new Go release, gofix helps make the
necessary changes to your programs. Gofix will handle the http, os, and syscall
package changes described below, and we will update the program to keep up with
future changes to the libraries. 
Gofix can’t
handle all situations perfectly, so read and test the changes it makes before
committing them.
See <a href="http://blog.golang.org/2011/04/introducing-gofix.html">the gofix blog post</a> for more
information.</p>

<h3 id="r57.lang">Language</h3>

<p>
<a href="/doc/go_spec.html#Receive_operator">Multiple assignment syntax</a> replaces the <code>closed</code> function.
The syntax for channel
receives allows an optional second assigned value, a boolean value
indicating whether the channel is closed. This code:
</p>

<pre>
	v := &lt;-ch
	if closed(ch) {
		// channel is closed
	}
</pre>

<p>should now be written as:</p>

<pre>
	v, ok := &lt;-ch
	if !ok {
		// channel is closed
	}
</pre>

<p><a href="/doc/go_spec.html#Label_scopes">Unused labels are now illegal</a>, just as unused local variables are.</p>

<h3 id="r57.pkg">Packages</h3>

<p>
<a href="/pkg/gob/">Package gob</a> will now encode and decode values of types that implement the
<a href="/pkg/gob/#GobEncoder">GobEncoder</a> and
<a href="/pkg/gob/#GobDecoder">GobDecoder</a> interfaces. This allows types with unexported
fields to transmit self-consistent descriptions; examples include 
<a href="/pkg/big/#Int.GobDecode">big.Int</a> and <a href="/pkg/big/#Rat.GobDecode">big.Rat</a>.
</p>

<p>
<a href="/pkg/http/">Package http</a> has been redesigned.
For clients, there are new
<a href="/pkg/http/#Client">Client</a> and <a href="/pkg/http/#Transport">Transport</a>
abstractions that give more control over HTTP details such as headers sent
and redirections followed.  These abstractions make it easy to implement
custom clients that add functionality such as <a href="http://code.google.com/p/goauth2/source/browse/oauth/oauth.go">OAuth2</a>.
For servers, <a href="/pkg/http/#ResponseWriter">ResponseWriter</a>
has dropped its non-essential methods.
The Hijack and Flush methods are no longer required;
code can test for them by checking whether a specific value implements
<a href="/pkg/http/#Hijacker">Hijacker</a> or <a href="/pkg/http/#Flusher">Flusher</a>.
The RemoteAddr and UsingTLS methods are replaced by <a href="/pkg/http/#Request">Request</a>'s
RemoteAddr and TLS fields.
The SetHeader method is replaced by a Header method;
its result, of type <a href="/pkg/http/#Header">Header</a>,
implements Set and other methods.
</p>

<p>
<a href="/pkg/net/">Package net</a>
drops the <code>laddr</code> argument from <a href="/pkg/net/#Conn.Dial">Dial</a>
and drops the <code>cname</code> return value
from <a href="/pkg/net/#LookupHost">LookupHost</a>.
The implementation now uses <a href="/cmd/cgo/">cgo</a> to implement
network name lookups using the C library getaddrinfo(3)
function when possible.  This ensures that Go and C programs
resolve names the same way and also avoids the OS X 
application-level firewall.
</p>

<p>
<a href="/pkg/os/">Package os</a>
introduces simplified <a href="/pkg/os/#File.Open">Open</a>
and <a href="/pkg/os/#File.Create">Create</a> functions.
The original Open is now available as <a href="/pkg/os/#File.OpenFile">OpenFile</a>.
The final three arguments to <a href="/pkg/os/#Process.StartProcess">StartProcess</a>
have been replaced by a pointer to a <a href="/pkg/os/#ProcAttr">ProcAttr</a>.
</p>

<p>
<a href="/pkg/reflect/">Package reflect</a> has been redesigned.
<a href="/pkg/reflect/#Type">Type</a> is now an interface that implements
all the possible type methods.
Instead of a type switch on a Type <code>t</code>, switch on <code>t.Kind()</code>.
<a href="/pkg/reflect/#Value">Value</a> is now a struct value that
implements all the possible value methods.
Instead of a type switch on a Value <code>v</code>, switch on <code>v.Kind()</code>.
Typeof and NewValue are now called <a href="/pkg/reflect/#Type.TypeOf">TypeOf</a> and <a href="/pkg/reflect/#Value.ValueOf">ValueOf</a>
To create a writable Value, use <code>New(t).Elem()</code> instead of <code>Zero(t)</code>.
See <a href="http://code.google.com/p/go/source/detail?r=843855f3c026">the change description</a>
for the full details.
The new API allows a more efficient implementation of Value
that avoids many of the allocations required by the previous API.
</p>

<p>
Remember that gofix will handle the bulk of the rewrites
necessary for these changes to package APIs.
</p>

<h3 id="r57.cmd">Tools</h3>

<p><a href="/cmd/gofix/">Gofix</a>, a new command, is described above.</p>

<p>
<a href="/cmd/gotest/">Gotest</a> is now a Go program instead of a shell script.
The new <code>-test.short</code> flag in combination with package testing's Short function
allows you to write tests that can be run in normal or &ldquo;short&rdquo; mode;
all.bash runs tests in short mode to reduce installation time.
The Makefiles know about the flag: use <code>make testshort</code>.
</p>

<p>
The run-time support now implements CPU and memory profiling.
Gotest's new 
<a href="/cmd/gotest/"><code>-test.cpuprofile</code> and
<code>-test.memprofile</code> flags</a> make it easy to
profile tests.
To add profiling to your web server, see the <a href="/pkg/http/pprof/">http/pprof</a>
documentation.
For other uses, see the <a href="/pkg/runtime/pprof/">runtime/pprof</a> documentation.
</p>

<h3 id="r57.minor">Minor revisions</h3>

<p>r57.1 fixes a <a href="http://code.google.com/p/go/source/detail?r=ff2bc62726e7145eb2ecc1e0f076998e4a8f86f0">nil pointer dereference in http.FormFile</a>.</p>
<p>r57.2 fixes a <a href="http://code.google.com/p/go/source/detail?r=063b0ff67d8277df03c956208abc068076818dae">use of uninitialized memory in programs that misuse <code>goto</code></a>.</p>

<h2 id="r56">r56 (released 2011/03/16)</h2>

<p>
The r56 release was the first stable release and corresponds to
<code><a href="weekly.html#2011-03-07">weekly.2011-03-07.1</a></code>.
The numbering starts at 56 because before this release,
what we now consider weekly snapshots were called releases.
</p>