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author | Christopher Speller <crspeller@gmail.com> | 2018-04-16 05:37:14 -0700 |
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committer | Joram Wilander <jwawilander@gmail.com> | 2018-04-16 08:37:14 -0400 |
commit | 6e2cb00008cbf09e556b00f87603797fcaa47e09 (patch) | |
tree | 3c0eb55ff4226a3f024aad373140d1fb860a6404 /vendor/golang.org/x/net/html/testdata/go1.html | |
parent | bf24f51c4e1cc6286885460672f7f449e8c6f5ef (diff) | |
download | chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.tar.gz chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.tar.bz2 chat-6e2cb00008cbf09e556b00f87603797fcaa47e09.zip |
Depenancy upgrades and movign to dep. (#8630)
Diffstat (limited to 'vendor/golang.org/x/net/html/testdata/go1.html')
-rw-r--r-- | vendor/golang.org/x/net/html/testdata/go1.html | 2237 |
1 files changed, 0 insertions, 2237 deletions
diff --git a/vendor/golang.org/x/net/html/testdata/go1.html b/vendor/golang.org/x/net/html/testdata/go1.html deleted file mode 100644 index d238257c3..000000000 --- a/vendor/golang.org/x/net/html/testdata/go1.html +++ /dev/null @@ -1,2237 +0,0 @@ -<!DOCTYPE html> -<html> -<head> -<meta http-equiv="Content-Type" content="text/html; charset=utf-8"> - - <title>Go 1 Release Notes - The Go Programming Language</title> - -<link type="text/css" rel="stylesheet" href="/doc/style.css"> -<script type="text/javascript" src="/doc/godocs.js"></script> - -<link rel="search" type="application/opensearchdescription+xml" title="godoc" href="/opensearch.xml" /> - -<script type="text/javascript"> -var _gaq = _gaq || []; -_gaq.push(["_setAccount", "UA-11222381-2"]); -_gaq.push(["_trackPageview"]); -</script> -</head> -<body> - -<div id="topbar"><div class="container wide"> - -<form method="GET" action="/search"> -<div id="menu"> -<a href="/doc/">Documents</a> -<a href="/ref/">References</a> -<a href="/pkg/">Packages</a> -<a href="/project/">The Project</a> -<a href="/help/">Help</a> -<input type="text" id="search" name="q" class="inactive" value="Search"> -</div> -<div id="heading"><a href="/">The Go Programming Language</a></div> -</form> - -</div></div> - -<div id="page" class="wide"> - - - <div id="plusone"><g:plusone size="small" annotation="none"></g:plusone></div> - <h1>Go 1 Release Notes</h1> - - - - -<div id="nav"></div> - - - - -<h2 id="introduction">Introduction to Go 1</h2> - -<p> -Go version 1, Go 1 for short, defines a language and a set of core libraries -that provide a stable foundation for creating reliable products, projects, and -publications. -</p> - -<p> -The driving motivation for Go 1 is stability for its users. People should be able to -write Go programs and expect that they will continue to compile and run without -change, on a time scale of years, including in production environments such as -Google App Engine. Similarly, people should be able to write books about Go, be -able to say which version of Go the book is describing, and have that version -number still be meaningful much later. -</p> - -<p> -Code that compiles in Go 1 should, with few exceptions, continue to compile and -run throughout the lifetime of that version, even as we issue updates and bug -fixes such as Go version 1.1, 1.2, and so on. Other than critical fixes, changes -made to the language and library for subsequent releases of Go 1 may -add functionality but will not break existing Go 1 programs. -<a href="go1compat.html">The Go 1 compatibility document</a> -explains the compatibility guidelines in more detail. -</p> - -<p> -Go 1 is a representation of Go as it used today, not a wholesale rethinking of -the language. We avoided designing new features and instead focused on cleaning -up problems and inconsistencies and improving portability. There are a number -changes to the Go language and packages that we had considered for some time and -prototyped but not released primarily because they are significant and -backwards-incompatible. Go 1 was an opportunity to get them out, which is -helpful for the long term, but also means that Go 1 introduces incompatibilities -for old programs. Fortunately, the <code>go</code> <code>fix</code> tool can -automate much of the work needed to bring programs up to the Go 1 standard. -</p> - -<p> -This document outlines the major changes in Go 1 that will affect programmers -updating existing code; its reference point is the prior release, r60 (tagged as -r60.3). It also explains how to update code from r60 to run under Go 1. -</p> - -<h2 id="language">Changes to the language</h2> - -<h3 id="append">Append</h3> - -<p> -The <code>append</code> predeclared variadic function makes it easy to grow a slice -by adding elements to the end. -A common use is to add bytes to the end of a byte slice when generating output. -However, <code>append</code> did not provide a way to append a string to a <code>[]byte</code>, -which is another common case. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/greeting := ..byte/` `/append.*hello/`}} ---> greeting := []byte{} - greeting = append(greeting, []byte("hello ")...)</pre> - -<p> -By analogy with the similar property of <code>copy</code>, Go 1 -permits a string to be appended (byte-wise) directly to a byte -slice, reducing the friction between strings and byte slices. -The conversion is no longer necessary: -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/append.*world/`}} ---> greeting = append(greeting, "world"...)</pre> - -<p> -<em>Updating</em>: -This is a new feature, so existing code needs no changes. -</p> - -<h3 id="close">Close</h3> - -<p> -The <code>close</code> predeclared function provides a mechanism -for a sender to signal that no more values will be sent. -It is important to the implementation of <code>for</code> <code>range</code> -loops over channels and is helpful in other situations. -Partly by design and partly because of race conditions that can occur otherwise, -it is intended for use only by the goroutine sending on the channel, -not by the goroutine receiving data. -However, before Go 1 there was no compile-time checking that <code>close</code> -was being used correctly. -</p> - -<p> -To close this gap, at least in part, Go 1 disallows <code>close</code> on receive-only channels. -Attempting to close such a channel is a compile-time error. -</p> - -<pre> - var c chan int - var csend chan<- int = c - var crecv <-chan int = c - close(c) // legal - close(csend) // legal - close(crecv) // illegal -</pre> - -<p> -<em>Updating</em>: -Existing code that attempts to close a receive-only channel was -erroneous even before Go 1 and should be fixed. The compiler will -now reject such code. -</p> - -<h3 id="literals">Composite literals</h3> - -<p> -In Go 1, a composite literal of array, slice, or map type can elide the -type specification for the elements' initializers if they are of pointer type. -All four of the initializations in this example are legal; the last one was illegal before Go 1. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/type Date struct/` `/STOP/`}} ---> type Date struct { - month string - day int - } - <span class="comment">// Struct values, fully qualified; always legal.</span> - holiday1 := []Date{ - Date{"Feb", 14}, - Date{"Nov", 11}, - Date{"Dec", 25}, - } - <span class="comment">// Struct values, type name elided; always legal.</span> - holiday2 := []Date{ - {"Feb", 14}, - {"Nov", 11}, - {"Dec", 25}, - } - <span class="comment">// Pointers, fully qualified, always legal.</span> - holiday3 := []*Date{ - &Date{"Feb", 14}, - &Date{"Nov", 11}, - &Date{"Dec", 25}, - } - <span class="comment">// Pointers, type name elided; legal in Go 1.</span> - holiday4 := []*Date{ - {"Feb", 14}, - {"Nov", 11}, - {"Dec", 25}, - }</pre> - -<p> -<em>Updating</em>: -This change has no effect on existing code, but the command -<code>gofmt</code> <code>-s</code> applied to existing source -will, among other things, elide explicit element types wherever permitted. -</p> - - -<h3 id="init">Goroutines during init</h3> - -<p> -The old language defined that <code>go</code> statements executed during initialization created goroutines but that they did not begin to run until initialization of the entire program was complete. -This introduced clumsiness in many places and, in effect, limited the utility -of the <code>init</code> construct: -if it was possible for another package to use the library during initialization, the library -was forced to avoid goroutines. -This design was done for reasons of simplicity and safety but, -as our confidence in the language grew, it seemed unnecessary. -Running goroutines during initialization is no more complex or unsafe than running them during normal execution. -</p> - -<p> -In Go 1, code that uses goroutines can be called from -<code>init</code> routines and global initialization expressions -without introducing a deadlock. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/PackageGlobal/` `/^}/`}} --->var PackageGlobal int - -func init() { - c := make(chan int) - go initializationFunction(c) - PackageGlobal = <-c -}</pre> - -<p> -<em>Updating</em>: -This is a new feature, so existing code needs no changes, -although it's possible that code that depends on goroutines not starting before <code>main</code> will break. -There was no such code in the standard repository. -</p> - -<h3 id="rune">The rune type</h3> - -<p> -The language spec allows the <code>int</code> type to be 32 or 64 bits wide, but current implementations set <code>int</code> to 32 bits even on 64-bit platforms. -It would be preferable to have <code>int</code> be 64 bits on 64-bit platforms. -(There are important consequences for indexing large slices.) -However, this change would waste space when processing Unicode characters with -the old language because the <code>int</code> type was also used to hold Unicode code points: each code point would waste an extra 32 bits of storage if <code>int</code> grew from 32 bits to 64. -</p> - -<p> -To make changing to 64-bit <code>int</code> feasible, -Go 1 introduces a new basic type, <code>rune</code>, to represent -individual Unicode code points. -It is an alias for <code>int32</code>, analogous to <code>byte</code> -as an alias for <code>uint8</code>. -</p> - -<p> -Character literals such as <code>'a'</code>, <code>'語'</code>, and <code>'\u0345'</code> -now have default type <code>rune</code>, -analogous to <code>1.0</code> having default type <code>float64</code>. -A variable initialized to a character constant will therefore -have type <code>rune</code> unless otherwise specified. -</p> - -<p> -Libraries have been updated to use <code>rune</code> rather than <code>int</code> -when appropriate. For instance, the functions <code>unicode.ToLower</code> and -relatives now take and return a <code>rune</code>. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/STARTRUNE/` `/ENDRUNE/`}} ---> delta := 'δ' <span class="comment">// delta has type rune.</span> - var DELTA rune - DELTA = unicode.ToUpper(delta) - epsilon := unicode.ToLower(DELTA + 1) - if epsilon != 'δ'+1 { - log.Fatal("inconsistent casing for Greek") - }</pre> - -<p> -<em>Updating</em>: -Most source code will be unaffected by this because the type inference from -<code>:=</code> initializers introduces the new type silently, and it propagates -from there. -Some code may get type errors that a trivial conversion will resolve. -</p> - -<h3 id="error">The error type</h3> - -<p> -Go 1 introduces a new built-in type, <code>error</code>, which has the following definition: -</p> - -<pre> - type error interface { - Error() string - } -</pre> - -<p> -Since the consequences of this type are all in the package library, -it is discussed <a href="#errors">below</a>. -</p> - -<h3 id="delete">Deleting from maps</h3> - -<p> -In the old language, to delete the entry with key <code>k</code> from map <code>m</code>, one wrote the statement, -</p> - -<pre> - m[k] = value, false -</pre> - -<p> -This syntax was a peculiar special case, the only two-to-one assignment. -It required passing a value (usually ignored) that is evaluated but discarded, -plus a boolean that was nearly always the constant <code>false</code>. -It did the job but was odd and a point of contention. -</p> - -<p> -In Go 1, that syntax has gone; instead there is a new built-in -function, <code>delete</code>. The call -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/delete\(m, k\)/`}} ---> delete(m, k)</pre> - -<p> -will delete the map entry retrieved by the expression <code>m[k]</code>. -There is no return value. Deleting a non-existent entry is a no-op. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will convert expressions of the form <code>m[k] = value, -false</code> into <code>delete(m, k)</code> when it is clear that -the ignored value can be safely discarded from the program and -<code>false</code> refers to the predefined boolean constant. -The fix tool -will flag other uses of the syntax for inspection by the programmer. -</p> - -<h3 id="iteration">Iterating in maps</h3> - -<p> -The old language specification did not define the order of iteration for maps, -and in practice it differed across hardware platforms. -This caused tests that iterated over maps to be fragile and non-portable, with the -unpleasant property that a test might always pass on one machine but break on another. -</p> - -<p> -In Go 1, the order in which elements are visited when iterating -over a map using a <code>for</code> <code>range</code> statement -is defined to be unpredictable, even if the same loop is run multiple -times with the same map. -Code should not assume that the elements are visited in any particular order. -</p> - -<p> -This change means that code that depends on iteration order is very likely to break early and be fixed long before it becomes a problem. -Just as important, it allows the map implementation to ensure better map balancing even when programs are using range loops to select an element from a map. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/Sunday/` `/^ }/`}} ---> m := map[string]int{"Sunday": 0, "Monday": 1} - for name, value := range m { - <span class="comment">// This loop should not assume Sunday will be visited first.</span> - f(name, value) - }</pre> - -<p> -<em>Updating</em>: -This is one change where tools cannot help. Most existing code -will be unaffected, but some programs may break or misbehave; we -recommend manual checking of all range statements over maps to -verify they do not depend on iteration order. There were a few such -examples in the standard repository; they have been fixed. -Note that it was already incorrect to depend on the iteration order, which -was unspecified. This change codifies the unpredictability. -</p> - -<h3 id="multiple_assignment">Multiple assignment</h3> - -<p> -The language specification has long guaranteed that in assignments -the right-hand-side expressions are all evaluated before any left-hand-side expressions are assigned. -To guarantee predictable behavior, -Go 1 refines the specification further. -</p> - -<p> -If the left-hand side of the assignment -statement contains expressions that require evaluation, such as -function calls or array indexing operations, these will all be done -using the usual left-to-right rule before any variables are assigned -their value. Once everything is evaluated, the actual assignments -proceed in left-to-right order. -</p> - -<p> -These examples illustrate the behavior. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/sa :=/` `/then sc.0. = 2/`}} ---> sa := []int{1, 2, 3} - i := 0 - i, sa[i] = 1, 2 <span class="comment">// sets i = 1, sa[0] = 2</span> - - sb := []int{1, 2, 3} - j := 0 - sb[j], j = 2, 1 <span class="comment">// sets sb[0] = 2, j = 1</span> - - sc := []int{1, 2, 3} - sc[0], sc[0] = 1, 2 <span class="comment">// sets sc[0] = 1, then sc[0] = 2 (so sc[0] = 2 at end)</span></pre> - -<p> -<em>Updating</em>: -This is one change where tools cannot help, but breakage is unlikely. -No code in the standard repository was broken by this change, and code -that depended on the previous unspecified behavior was already incorrect. -</p> - -<h3 id="shadowing">Returns and shadowed variables</h3> - -<p> -A common mistake is to use <code>return</code> (without arguments) after an assignment to a variable that has the same name as a result variable but is not the same variable. -This situation is called <em>shadowing</em>: the result variable has been shadowed by another variable with the same name declared in an inner scope. -</p> - -<p> -In functions with named return values, -the Go 1 compilers disallow return statements without arguments if any of the named return values is shadowed at the point of the return statement. -(It isn't part of the specification, because this is one area we are still exploring; -the situation is analogous to the compilers rejecting functions that do not end with an explicit return statement.) -</p> - -<p> -This function implicitly returns a shadowed return value and will be rejected by the compiler: -</p> - -<pre> - func Bug() (i, j, k int) { - for i = 0; i < 5; i++ { - for j := 0; j < 5; j++ { // Redeclares j. - k += i*j - if k > 100 { - return // Rejected: j is shadowed here. - } - } - } - return // OK: j is not shadowed here. - } -</pre> - -<p> -<em>Updating</em>: -Code that shadows return values in this way will be rejected by the compiler and will need to be fixed by hand. -The few cases that arose in the standard repository were mostly bugs. -</p> - -<h3 id="unexported">Copying structs with unexported fields</h3> - -<p> -The old language did not allow a package to make a copy of a struct value containing unexported fields belonging to a different package. -There was, however, a required exception for a method receiver; -also, the implementations of <code>copy</code> and <code>append</code> have never honored the restriction. -</p> - -<p> -Go 1 will allow packages to copy struct values containing unexported fields from other packages. -Besides resolving the inconsistency, -this change admits a new kind of API: a package can return an opaque value without resorting to a pointer or interface. -The new implementations of <code>time.Time</code> and -<code>reflect.Value</code> are examples of types taking advantage of this new property. -</p> - -<p> -As an example, if package <code>p</code> includes the definitions, -</p> - -<pre> - type Struct struct { - Public int - secret int - } - func NewStruct(a int) Struct { // Note: not a pointer. - return Struct{a, f(a)} - } - func (s Struct) String() string { - return fmt.Sprintf("{%d (secret %d)}", s.Public, s.secret) - } -</pre> - -<p> -a package that imports <code>p</code> can assign and copy values of type -<code>p.Struct</code> at will. -Behind the scenes the unexported fields will be assigned and copied just -as if they were exported, -but the client code will never be aware of them. The code -</p> - -<pre> - import "p" - - myStruct := p.NewStruct(23) - copyOfMyStruct := myStruct - fmt.Println(myStruct, copyOfMyStruct) -</pre> - -<p> -will show that the secret field of the struct has been copied to the new value. -</p> - -<p> -<em>Updating</em>: -This is a new feature, so existing code needs no changes. -</p> - -<h3 id="equality">Equality</h3> - -<p> -Before Go 1, the language did not define equality on struct and array values. -This meant, -among other things, that structs and arrays could not be used as map keys. -On the other hand, Go did define equality on function and map values. -Function equality was problematic in the presence of closures -(when are two closures equal?) -while map equality compared pointers, not the maps' content, which was usually -not what the user would want. -</p> - -<p> -Go 1 addressed these issues. -First, structs and arrays can be compared for equality and inequality -(<code>==</code> and <code>!=</code>), -and therefore be used as map keys, -provided they are composed from elements for which equality is also defined, -using element-wise comparison. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/type Day struct/` `/Printf/`}} ---> type Day struct { - long string - short string - } - Christmas := Day{"Christmas", "XMas"} - Thanksgiving := Day{"Thanksgiving", "Turkey"} - holiday := map[Day]bool{ - Christmas: true, - Thanksgiving: true, - } - fmt.Printf("Christmas is a holiday: %t\n", holiday[Christmas])</pre> - -<p> -Second, Go 1 removes the definition of equality for function values, -except for comparison with <code>nil</code>. -Finally, map equality is gone too, also except for comparison with <code>nil</code>. -</p> - -<p> -Note that equality is still undefined for slices, for which the -calculation is in general infeasible. Also note that the ordered -comparison operators (<code><</code> <code><=</code> -<code>></code> <code>>=</code>) are still undefined for -structs and arrays. - -<p> -<em>Updating</em>: -Struct and array equality is a new feature, so existing code needs no changes. -Existing code that depends on function or map equality will be -rejected by the compiler and will need to be fixed by hand. -Few programs will be affected, but the fix may require some -redesign. -</p> - -<h2 id="packages">The package hierarchy</h2> - -<p> -Go 1 addresses many deficiencies in the old standard library and -cleans up a number of packages, making them more internally consistent -and portable. -</p> - -<p> -This section describes how the packages have been rearranged in Go 1. -Some have moved, some have been renamed, some have been deleted. -New packages are described in later sections. -</p> - -<h3 id="hierarchy">The package hierarchy</h3> - -<p> -Go 1 has a rearranged package hierarchy that groups related items -into subdirectories. For instance, <code>utf8</code> and -<code>utf16</code> now occupy subdirectories of <code>unicode</code>. -Also, <a href="#subrepo">some packages</a> have moved into -subrepositories of -<a href="http://code.google.com/p/go"><code>code.google.com/p/go</code></a> -while <a href="#deleted">others</a> have been deleted outright. -</p> - -<table class="codetable" frame="border" summary="Moved packages"> -<colgroup align="left" width="60%"></colgroup> -<colgroup align="left" width="40%"></colgroup> -<tr> -<th align="left">Old path</th> -<th align="left">New path</th> -</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>asn1</td> <td>encoding/asn1</td></tr> -<tr><td>csv</td> <td>encoding/csv</td></tr> -<tr><td>gob</td> <td>encoding/gob</td></tr> -<tr><td>json</td> <td>encoding/json</td></tr> -<tr><td>xml</td> <td>encoding/xml</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>exp/template/html</td> <td>html/template</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>big</td> <td>math/big</td></tr> -<tr><td>cmath</td> <td>math/cmplx</td></tr> -<tr><td>rand</td> <td>math/rand</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>http</td> <td>net/http</td></tr> -<tr><td>http/cgi</td> <td>net/http/cgi</td></tr> -<tr><td>http/fcgi</td> <td>net/http/fcgi</td></tr> -<tr><td>http/httptest</td> <td>net/http/httptest</td></tr> -<tr><td>http/pprof</td> <td>net/http/pprof</td></tr> -<tr><td>mail</td> <td>net/mail</td></tr> -<tr><td>rpc</td> <td>net/rpc</td></tr> -<tr><td>rpc/jsonrpc</td> <td>net/rpc/jsonrpc</td></tr> -<tr><td>smtp</td> <td>net/smtp</td></tr> -<tr><td>url</td> <td>net/url</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>exec</td> <td>os/exec</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>scanner</td> <td>text/scanner</td></tr> -<tr><td>tabwriter</td> <td>text/tabwriter</td></tr> -<tr><td>template</td> <td>text/template</td></tr> -<tr><td>template/parse</td> <td>text/template/parse</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>utf8</td> <td>unicode/utf8</td></tr> -<tr><td>utf16</td> <td>unicode/utf16</td></tr> -</table> - -<p> -Note that the package names for the old <code>cmath</code> and -<code>exp/template/html</code> packages have changed to <code>cmplx</code> -and <code>template</code>. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update all imports and package renames for packages that -remain inside the standard repository. Programs that import packages -that are no longer in the standard repository will need to be edited -by hand. -</p> - -<h3 id="exp">The package tree exp</h3> - -<p> -Because they are not standardized, the packages under the <code>exp</code> directory will not be available in the -standard Go 1 release distributions, although they will be available in source code form -in <a href="http://code.google.com/p/go/">the repository</a> for -developers who wish to use them. -</p> - -<p> -Several packages have moved under <code>exp</code> at the time of Go 1's release: -</p> - -<ul> -<li><code>ebnf</code></li> -<li><code>html</code><sup>†</sup></li> -<li><code>go/types</code></li> -</ul> - -<p> -(<sup>†</sup>The <code>EscapeString</code> and <code>UnescapeString</code> types remain -in package <code>html</code>.) -</p> - -<p> -All these packages are available under the same names, with the prefix <code>exp/</code>: <code>exp/ebnf</code> etc. -</p> - -<p> -Also, the <code>utf8.String</code> type has been moved to its own package, <code>exp/utf8string</code>. -</p> - -<p> -Finally, the <code>gotype</code> command now resides in <code>exp/gotype</code>, while -<code>ebnflint</code> is now in <code>exp/ebnflint</code>. -If they are installed, they now reside in <code>$GOROOT/bin/tool</code>. -</p> - -<p> -<em>Updating</em>: -Code that uses packages in <code>exp</code> will need to be updated by hand, -or else compiled from an installation that has <code>exp</code> available. -The <code>go</code> <code>fix</code> tool or the compiler will complain about such uses. -</p> - -<h3 id="old">The package tree old</h3> - -<p> -Because they are deprecated, the packages under the <code>old</code> directory will not be available in the -standard Go 1 release distributions, although they will be available in source code form for -developers who wish to use them. -</p> - -<p> -The packages in their new locations are: -</p> - -<ul> -<li><code>old/netchan</code></li> -<li><code>old/regexp</code></li> -<li><code>old/template</code></li> -</ul> - -<p> -<em>Updating</em>: -Code that uses packages now in <code>old</code> will need to be updated by hand, -or else compiled from an installation that has <code>old</code> available. -The <code>go</code> <code>fix</code> tool will warn about such uses. -</p> - -<h3 id="deleted">Deleted packages</h3> - -<p> -Go 1 deletes several packages outright: -</p> - -<ul> -<li><code>container/vector</code></li> -<li><code>exp/datafmt</code></li> -<li><code>go/typechecker</code></li> -<li><code>try</code></li> -</ul> - -<p> -and also the command <code>gotry</code>. -</p> - -<p> -<em>Updating</em>: -Code that uses <code>container/vector</code> should be updated to use -slices directly. See -<a href="http://code.google.com/p/go-wiki/wiki/SliceTricks">the Go -Language Community Wiki</a> for some suggestions. -Code that uses the other packages (there should be almost zero) will need to be rethought. -</p> - -<h3 id="subrepo">Packages moving to subrepositories</h3> - -<p> -Go 1 has moved a number of packages into other repositories, usually sub-repositories of -<a href="http://code.google.com/p/go/">the main Go repository</a>. -This table lists the old and new import paths: - -<table class="codetable" frame="border" summary="Sub-repositories"> -<colgroup align="left" width="40%"></colgroup> -<colgroup align="left" width="60%"></colgroup> -<tr> -<th align="left">Old</th> -<th align="left">New</th> -</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>crypto/bcrypt</td> <td>code.google.com/p/go.crypto/bcrypt</tr> -<tr><td>crypto/blowfish</td> <td>code.google.com/p/go.crypto/blowfish</tr> -<tr><td>crypto/cast5</td> <td>code.google.com/p/go.crypto/cast5</tr> -<tr><td>crypto/md4</td> <td>code.google.com/p/go.crypto/md4</tr> -<tr><td>crypto/ocsp</td> <td>code.google.com/p/go.crypto/ocsp</tr> -<tr><td>crypto/openpgp</td> <td>code.google.com/p/go.crypto/openpgp</tr> -<tr><td>crypto/openpgp/armor</td> <td>code.google.com/p/go.crypto/openpgp/armor</tr> -<tr><td>crypto/openpgp/elgamal</td> <td>code.google.com/p/go.crypto/openpgp/elgamal</tr> -<tr><td>crypto/openpgp/errors</td> <td>code.google.com/p/go.crypto/openpgp/errors</tr> -<tr><td>crypto/openpgp/packet</td> <td>code.google.com/p/go.crypto/openpgp/packet</tr> -<tr><td>crypto/openpgp/s2k</td> <td>code.google.com/p/go.crypto/openpgp/s2k</tr> -<tr><td>crypto/ripemd160</td> <td>code.google.com/p/go.crypto/ripemd160</tr> -<tr><td>crypto/twofish</td> <td>code.google.com/p/go.crypto/twofish</tr> -<tr><td>crypto/xtea</td> <td>code.google.com/p/go.crypto/xtea</tr> -<tr><td>exp/ssh</td> <td>code.google.com/p/go.crypto/ssh</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>image/bmp</td> <td>code.google.com/p/go.image/bmp</tr> -<tr><td>image/tiff</td> <td>code.google.com/p/go.image/tiff</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>net/dict</td> <td>code.google.com/p/go.net/dict</tr> -<tr><td>net/websocket</td> <td>code.google.com/p/go.net/websocket</tr> -<tr><td>exp/spdy</td> <td>code.google.com/p/go.net/spdy</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>encoding/git85</td> <td>code.google.com/p/go.codereview/git85</tr> -<tr><td>patch</td> <td>code.google.com/p/go.codereview/patch</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>exp/wingui</td> <td>code.google.com/p/gowingui</tr> -</table> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update imports of these packages to use the new import paths. -Installations that depend on these packages will need to install them using -a <code>go get</code> command. -</p> - -<h2 id="major">Major changes to the library</h2> - -<p> -This section describes significant changes to the core libraries, the ones that -affect the most programs. -</p> - -<h3 id="errors">The error type and errors package</h3> - -<p> -The placement of <code>os.Error</code> in package <code>os</code> is mostly historical: errors first came up when implementing package <code>os</code>, and they seemed system-related at the time. -Since then it has become clear that errors are more fundamental than the operating system. For example, it would be nice to use <code>Errors</code> in packages that <code>os</code> depends on, like <code>syscall</code>. -Also, having <code>Error</code> in <code>os</code> introduces many dependencies on <code>os</code> that would otherwise not exist. -</p> - -<p> -Go 1 solves these problems by introducing a built-in <code>error</code> interface type and a separate <code>errors</code> package (analogous to <code>bytes</code> and <code>strings</code>) that contains utility functions. -It replaces <code>os.NewError</code> with -<a href="/pkg/errors/#New"><code>errors.New</code></a>, -giving errors a more central place in the environment. -</p> - -<p> -So the widely-used <code>String</code> method does not cause accidental satisfaction -of the <code>error</code> interface, the <code>error</code> interface uses instead -the name <code>Error</code> for that method: -</p> - -<pre> - type error interface { - Error() string - } -</pre> - -<p> -The <code>fmt</code> library automatically invokes <code>Error</code>, as it already -does for <code>String</code>, for easy printing of error values. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/START ERROR EXAMPLE/` `/END ERROR EXAMPLE/`}} --->type SyntaxError struct { - File string - Line int - Message string -} - -func (se *SyntaxError) Error() string { - return fmt.Sprintf("%s:%d: %s", se.File, se.Line, se.Message) -}</pre> - -<p> -All standard packages have been updated to use the new interface; the old <code>os.Error</code> is gone. -</p> - -<p> -A new package, <a href="/pkg/errors/"><code>errors</code></a>, contains the function -</p> - -<pre> -func New(text string) error -</pre> - -<p> -to turn a string into an error. It replaces the old <code>os.NewError</code>. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/ErrSyntax/`}} ---> var ErrSyntax = errors.New("syntax error")</pre> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update almost all code affected by the change. -Code that defines error types with a <code>String</code> method will need to be updated -by hand to rename the methods to <code>Error</code>. -</p> - -<h3 id="errno">System call errors</h3> - -<p> -The old <code>syscall</code> package, which predated <code>os.Error</code> -(and just about everything else), -returned errors as <code>int</code> values. -In turn, the <code>os</code> package forwarded many of these errors, such -as <code>EINVAL</code>, but using a different set of errors on each platform. -This behavior was unpleasant and unportable. -</p> - -<p> -In Go 1, the -<a href="/pkg/syscall/"><code>syscall</code></a> -package instead returns an <code>error</code> for system call errors. -On Unix, the implementation is done by a -<a href="/pkg/syscall/#Errno"><code>syscall.Errno</code></a> type -that satisfies <code>error</code> and replaces the old <code>os.Errno</code>. -</p> - -<p> -The changes affecting <code>os.EINVAL</code> and relatives are -described <a href="#os">elsewhere</a>. - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update almost all code affected by the change. -Regardless, most code should use the <code>os</code> package -rather than <code>syscall</code> and so will be unaffected. -</p> - -<h3 id="time">Time</h3> - -<p> -Time is always a challenge to support well in a programming language. -The old Go <code>time</code> package had <code>int64</code> units, no -real type safety, -and no distinction between absolute times and durations. -</p> - -<p> -One of the most sweeping changes in the Go 1 library is therefore a -complete redesign of the -<a href="/pkg/time/"><code>time</code></a> package. -Instead of an integer number of nanoseconds as an <code>int64</code>, -and a separate <code>*time.Time</code> type to deal with human -units such as hours and years, -there are now two fundamental types: -<a href="/pkg/time/#Time"><code>time.Time</code></a> -(a value, so the <code>*</code> is gone), which represents a moment in time; -and <a href="/pkg/time/#Duration"><code>time.Duration</code></a>, -which represents an interval. -Both have nanosecond resolution. -A <code>Time</code> can represent any time into the ancient -past and remote future, while a <code>Duration</code> can -span plus or minus only about 290 years. -There are methods on these types, plus a number of helpful -predefined constant durations such as <code>time.Second</code>. -</p> - -<p> -Among the new methods are things like -<a href="/pkg/time/#Time.Add"><code>Time.Add</code></a>, -which adds a <code>Duration</code> to a <code>Time</code>, and -<a href="/pkg/time/#Time.Sub"><code>Time.Sub</code></a>, -which subtracts two <code>Times</code> to yield a <code>Duration</code>. -</p> - -<p> -The most important semantic change is that the Unix epoch (Jan 1, 1970) is now -relevant only for those functions and methods that mention Unix: -<a href="/pkg/time/#Unix"><code>time.Unix</code></a> -and the <a href="/pkg/time/#Time.Unix"><code>Unix</code></a> -and <a href="/pkg/time/#Time.UnixNano"><code>UnixNano</code></a> methods -of the <code>Time</code> type. -In particular, -<a href="/pkg/time/#Now"><code>time.Now</code></a> -returns a <code>time.Time</code> value rather than, in the old -API, an integer nanosecond count since the Unix epoch. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/sleepUntil/` `/^}/`}} ---><span class="comment">// sleepUntil sleeps until the specified time. It returns immediately if it's too late.</span> -func sleepUntil(wakeup time.Time) { - now := time.Now() <span class="comment">// A Time.</span> - if !wakeup.After(now) { - return - } - delta := wakeup.Sub(now) <span class="comment">// A Duration.</span> - fmt.Printf("Sleeping for %.3fs\n", delta.Seconds()) - time.Sleep(delta) -}</pre> - -<p> -The new types, methods, and constants have been propagated through -all the standard packages that use time, such as <code>os</code> and -its representation of file time stamps. -</p> - -<p> -<em>Updating</em>: -The <code>go</code> <code>fix</code> tool will update many uses of the old <code>time</code> package to use the new -types and methods, although it does not replace values such as <code>1e9</code> -representing nanoseconds per second. -Also, because of type changes in some of the values that arise, -some of the expressions rewritten by the fix tool may require -further hand editing; in such cases the rewrite will include -the correct function or method for the old functionality, but -may have the wrong type or require further analysis. -</p> - -<h2 id="minor">Minor changes to the library</h2> - -<p> -This section describes smaller changes, such as those to less commonly -used packages or that affect -few programs beyond the need to run <code>go</code> <code>fix</code>. -This category includes packages that are new in Go 1. -Collectively they improve portability, regularize behavior, and -make the interfaces more modern and Go-like. -</p> - -<h3 id="archive_zip">The archive/zip package</h3> - -<p> -In Go 1, <a href="/pkg/archive/zip/#Writer"><code>*zip.Writer</code></a> no -longer has a <code>Write</code> method. Its presence was a mistake. -</p> - -<p> -<em>Updating</em>: -What little code is affected will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="bufio">The bufio package</h3> - -<p> -In Go 1, <a href="/pkg/bufio/#NewReaderSize"><code>bufio.NewReaderSize</code></a> -and -<a href="/pkg/bufio/#NewWriterSize"><code>bufio.NewWriterSize</code></a> -functions no longer return an error for invalid sizes. -If the argument size is too small or invalid, it is adjusted. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update calls that assign the error to _. -Calls that aren't fixed will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="compress">The compress/flate, compress/gzip and compress/zlib packages</h3> - -<p> -In Go 1, the <code>NewWriterXxx</code> functions in -<a href="/pkg/compress/flate"><code>compress/flate</code></a>, -<a href="/pkg/compress/gzip"><code>compress/gzip</code></a> and -<a href="/pkg/compress/zlib"><code>compress/zlib</code></a> -all return <code>(*Writer, error)</code> if they take a compression level, -and <code>*Writer</code> otherwise. Package <code>gzip</code>'s -<code>Compressor</code> and <code>Decompressor</code> types have been renamed -to <code>Writer</code> and <code>Reader</code>. Package <code>flate</code>'s -<code>WrongValueError</code> type has been removed. -</p> - -<p> -<em>Updating</em> -Running <code>go</code> <code>fix</code> will update old names and calls that assign the error to _. -Calls that aren't fixed will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="crypto_aes_des">The crypto/aes and crypto/des packages</h3> - -<p> -In Go 1, the <code>Reset</code> method has been removed. Go does not guarantee -that memory is not copied and therefore this method was misleading. -</p> - -<p> -The cipher-specific types <code>*aes.Cipher</code>, <code>*des.Cipher</code>, -and <code>*des.TripleDESCipher</code> have been removed in favor of -<code>cipher.Block</code>. -</p> - -<p> -<em>Updating</em>: -Remove the calls to Reset. Replace uses of the specific cipher types with -cipher.Block. -</p> - -<h3 id="crypto_elliptic">The crypto/elliptic package</h3> - -<p> -In Go 1, <a href="/pkg/crypto/elliptic/#Curve"><code>elliptic.Curve</code></a> -has been made an interface to permit alternative implementations. The curve -parameters have been moved to the -<a href="/pkg/crypto/elliptic/#CurveParams"><code>elliptic.CurveParams</code></a> -structure. -</p> - -<p> -<em>Updating</em>: -Existing users of <code>*elliptic.Curve</code> will need to change to -simply <code>elliptic.Curve</code>. Calls to <code>Marshal</code>, -<code>Unmarshal</code> and <code>GenerateKey</code> are now functions -in <code>crypto/elliptic</code> that take an <code>elliptic.Curve</code> -as their first argument. -</p> - -<h3 id="crypto_hmac">The crypto/hmac package</h3> - -<p> -In Go 1, the hash-specific functions, such as <code>hmac.NewMD5</code>, have -been removed from <code>crypto/hmac</code>. Instead, <code>hmac.New</code> takes -a function that returns a <code>hash.Hash</code>, such as <code>md5.New</code>. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will perform the needed changes. -</p> - -<h3 id="crypto_x509">The crypto/x509 package</h3> - -<p> -In Go 1, the -<a href="/pkg/crypto/x509/#CreateCertificate"><code>CreateCertificate</code></a> -and -<a href="/pkg/crypto/x509/#CreateCRL"><code>CreateCRL</code></a> -functions in <code>crypto/x509</code> have been altered to take an -<code>interface{}</code> where they previously took a <code>*rsa.PublicKey</code> -or <code>*rsa.PrivateKey</code>. This will allow other public key algorithms -to be implemented in the future. -</p> - -<p> -<em>Updating</em>: -No changes will be needed. -</p> - -<h3 id="encoding_binary">The encoding/binary package</h3> - -<p> -In Go 1, the <code>binary.TotalSize</code> function has been replaced by -<a href="/pkg/encoding/binary/#Size"><code>Size</code></a>, -which takes an <code>interface{}</code> argument rather than -a <code>reflect.Value</code>. -</p> - -<p> -<em>Updating</em>: -What little code is affected will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="encoding_xml">The encoding/xml package</h3> - -<p> -In Go 1, the <a href="/pkg/encoding/xml/"><code>xml</code></a> package -has been brought closer in design to the other marshaling packages such -as <a href="/pkg/encoding/gob/"><code>encoding/gob</code></a>. -</p> - -<p> -The old <code>Parser</code> type is renamed -<a href="/pkg/encoding/xml/#Decoder"><code>Decoder</code></a> and has a new -<a href="/pkg/encoding/xml/#Decoder.Decode"><code>Decode</code></a> method. An -<a href="/pkg/encoding/xml/#Encoder"><code>Encoder</code></a> type was also introduced. -</p> - -<p> -The functions <a href="/pkg/encoding/xml/#Marshal"><code>Marshal</code></a> -and <a href="/pkg/encoding/xml/#Unmarshal"><code>Unmarshal</code></a> -work with <code>[]byte</code> values now. To work with streams, -use the new <a href="/pkg/encoding/xml/#Encoder"><code>Encoder</code></a> -and <a href="/pkg/encoding/xml/#Decoder"><code>Decoder</code></a> types. -</p> - -<p> -When marshaling or unmarshaling values, the format of supported flags in -field tags has changed to be closer to the -<a href="/pkg/encoding/json"><code>json</code></a> package -(<code>`xml:"name,flag"`</code>). The matching done between field tags, field -names, and the XML attribute and element names is now case-sensitive. -The <code>XMLName</code> field tag, if present, must also match the name -of the XML element being marshaled. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update most uses of the package except for some calls to -<code>Unmarshal</code>. Special care must be taken with field tags, -since the fix tool will not update them and if not fixed by hand they will -misbehave silently in some cases. For example, the old -<code>"attr"</code> is now written <code>",attr"</code> while plain -<code>"attr"</code> remains valid but with a different meaning. -</p> - -<h3 id="expvar">The expvar package</h3> - -<p> -In Go 1, the <code>RemoveAll</code> function has been removed. -The <code>Iter</code> function and Iter method on <code>*Map</code> have -been replaced by -<a href="/pkg/expvar/#Do"><code>Do</code></a> -and -<a href="/pkg/expvar/#Map.Do"><code>(*Map).Do</code></a>. -</p> - -<p> -<em>Updating</em>: -Most code using <code>expvar</code> will not need changing. The rare code that used -<code>Iter</code> can be updated to pass a closure to <code>Do</code> to achieve the same effect. -</p> - -<h3 id="flag">The flag package</h3> - -<p> -In Go 1, the interface <a href="/pkg/flag/#Value"><code>flag.Value</code></a> has changed slightly. -The <code>Set</code> method now returns an <code>error</code> instead of -a <code>bool</code> to indicate success or failure. -</p> - -<p> -There is also a new kind of flag, <code>Duration</code>, to support argument -values specifying time intervals. -Values for such flags must be given units, just as <code>time.Duration</code> -formats them: <code>10s</code>, <code>1h30m</code>, etc. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/timeout/`}} --->var timeout = flag.Duration("timeout", 30*time.Second, "how long to wait for completion")</pre> - -<p> -<em>Updating</em>: -Programs that implement their own flags will need minor manual fixes to update their -<code>Set</code> methods. -The <code>Duration</code> flag is new and affects no existing code. -</p> - - -<h3 id="go">The go/* packages</h3> - -<p> -Several packages under <code>go</code> have slightly revised APIs. -</p> - -<p> -A concrete <code>Mode</code> type was introduced for configuration mode flags -in the packages -<a href="/pkg/go/scanner/"><code>go/scanner</code></a>, -<a href="/pkg/go/parser/"><code>go/parser</code></a>, -<a href="/pkg/go/printer/"><code>go/printer</code></a>, and -<a href="/pkg/go/doc/"><code>go/doc</code></a>. -</p> - -<p> -The modes <code>AllowIllegalChars</code> and <code>InsertSemis</code> have been removed -from the <a href="/pkg/go/scanner/"><code>go/scanner</code></a> package. They were mostly -useful for scanning text other then Go source files. Instead, the -<a href="/pkg/text/scanner/"><code>text/scanner</code></a> package should be used -for that purpose. -</p> - -<p> -The <a href="/pkg/go/scanner/#ErrorHandler"><code>ErrorHandler</code></a> provided -to the scanner's <a href="/pkg/go/scanner/#Scanner.Init"><code>Init</code></a> method is -now simply a function rather than an interface. The <code>ErrorVector</code> type has -been removed in favor of the (existing) <a href="/pkg/go/scanner/#ErrorList"><code>ErrorList</code></a> -type, and the <code>ErrorVector</code> methods have been migrated. Instead of embedding -an <code>ErrorVector</code> in a client of the scanner, now a client should maintain -an <code>ErrorList</code>. -</p> - -<p> -The set of parse functions provided by the <a href="/pkg/go/parser/"><code>go/parser</code></a> -package has been reduced to the primary parse function -<a href="/pkg/go/parser/#ParseFile"><code>ParseFile</code></a>, and a couple of -convenience functions <a href="/pkg/go/parser/#ParseDir"><code>ParseDir</code></a> -and <a href="/pkg/go/parser/#ParseExpr"><code>ParseExpr</code></a>. -</p> - -<p> -The <a href="/pkg/go/printer/"><code>go/printer</code></a> package supports an additional -configuration mode <a href="/pkg/go/printer/#Mode"><code>SourcePos</code></a>; -if set, the printer will emit <code>//line</code> comments such that the generated -output contains the original source code position information. The new type -<a href="/pkg/go/printer/#CommentedNode"><code>CommentedNode</code></a> can be -used to provide comments associated with an arbitrary -<a href="/pkg/go/ast/#Node"><code>ast.Node</code></a> (until now only -<a href="/pkg/go/ast/#File"><code>ast.File</code></a> carried comment information). -</p> - -<p> -The type names of the <a href="/pkg/go/doc/"><code>go/doc</code></a> package have been -streamlined by removing the <code>Doc</code> suffix: <code>PackageDoc</code> -is now <code>Package</code>, <code>ValueDoc</code> is <code>Value</code>, etc. -Also, all types now consistently have a <code>Name</code> field (or <code>Names</code>, -in the case of type <code>Value</code>) and <code>Type.Factories</code> has become -<code>Type.Funcs</code>. -Instead of calling <code>doc.NewPackageDoc(pkg, importpath)</code>, -documentation for a package is created with: -</p> - -<pre> - doc.New(pkg, importpath, mode) -</pre> - -<p> -where the new <code>mode</code> parameter specifies the operation mode: -if set to <a href="/pkg/go/doc/#AllDecls"><code>AllDecls</code></a>, all declarations -(not just exported ones) are considered. -The function <code>NewFileDoc</code> was removed, and the function -<code>CommentText</code> has become the method -<a href="/pkg/go/ast/#Text"><code>Text</code></a> of -<a href="/pkg/go/ast/#CommentGroup"><code>ast.CommentGroup</code></a>. -</p> - -<p> -In package <a href="/pkg/go/token/"><code>go/token</code></a>, the -<a href="/pkg/go/token/#FileSet"><code>token.FileSet</code></a> method <code>Files</code> -(which originally returned a channel of <code>*token.File</code>s) has been replaced -with the iterator <a href="/pkg/go/token/#FileSet.Iterate"><code>Iterate</code></a> that -accepts a function argument instead. -</p> - -<p> -In package <a href="/pkg/go/build/"><code>go/build</code></a>, the API -has been nearly completely replaced. -The package still computes Go package information -but it does not run the build: the <code>Cmd</code> and <code>Script</code> -types are gone. -(To build code, use the new -<a href="/cmd/go/"><code>go</code></a> command instead.) -The <code>DirInfo</code> type is now named -<a href="/pkg/go/build/#Package"><code>Package</code></a>. -<code>FindTree</code> and <code>ScanDir</code> are replaced by -<a href="/pkg/go/build/#Import"><code>Import</code></a> -and -<a href="/pkg/go/build/#ImportDir"><code>ImportDir</code></a>. -</p> - -<p> -<em>Updating</em>: -Code that uses packages in <code>go</code> will have to be updated by hand; the -compiler will reject incorrect uses. Templates used in conjunction with any of the -<code>go/doc</code> types may need manual fixes; the renamed fields will lead -to run-time errors. -</p> - -<h3 id="hash">The hash package</h3> - -<p> -In Go 1, the definition of <a href="/pkg/hash/#Hash"><code>hash.Hash</code></a> includes -a new method, <code>BlockSize</code>. This new method is used primarily in the -cryptographic libraries. -</p> - -<p> -The <code>Sum</code> method of the -<a href="/pkg/hash/#Hash"><code>hash.Hash</code></a> interface now takes a -<code>[]byte</code> argument, to which the hash value will be appended. -The previous behavior can be recreated by adding a <code>nil</code> argument to the call. -</p> - -<p> -<em>Updating</em>: -Existing implementations of <code>hash.Hash</code> will need to add a -<code>BlockSize</code> method. Hashes that process the input one byte at -a time can implement <code>BlockSize</code> to return 1. -Running <code>go</code> <code>fix</code> will update calls to the <code>Sum</code> methods of the various -implementations of <code>hash.Hash</code>. -</p> - -<p> -<em>Updating</em>: -Since the package's functionality is new, no updating is necessary. -</p> - -<h3 id="http">The http package</h3> - -<p> -In Go 1 the <a href="/pkg/net/http/"><code>http</code></a> package is refactored, -putting some of the utilities into a -<a href="/pkg/net/http/httputil/"><code>httputil</code></a> subdirectory. -These pieces are only rarely needed by HTTP clients. -The affected items are: -</p> - -<ul> -<li>ClientConn</li> -<li>DumpRequest</li> -<li>DumpRequestOut</li> -<li>DumpResponse</li> -<li>NewChunkedReader</li> -<li>NewChunkedWriter</li> -<li>NewClientConn</li> -<li>NewProxyClientConn</li> -<li>NewServerConn</li> -<li>NewSingleHostReverseProxy</li> -<li>ReverseProxy</li> -<li>ServerConn</li> -</ul> - -<p> -The <code>Request.RawURL</code> field has been removed; it was a -historical artifact. -</p> - -<p> -The <code>Handle</code> and <code>HandleFunc</code> -functions, and the similarly-named methods of <code>ServeMux</code>, -now panic if an attempt is made to register the same pattern twice. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update the few programs that are affected except for -uses of <code>RawURL</code>, which must be fixed by hand. -</p> - -<h3 id="image">The image package</h3> - -<p> -The <a href="/pkg/image/"><code>image</code></a> package has had a number of -minor changes, rearrangements and renamings. -</p> - -<p> -Most of the color handling code has been moved into its own package, -<a href="/pkg/image/color/"><code>image/color</code></a>. -For the elements that moved, a symmetry arises; for instance, -each pixel of an -<a href="/pkg/image/#RGBA"><code>image.RGBA</code></a> -is a -<a href="/pkg/image/color/#RGBA"><code>color.RGBA</code></a>. -</p> - -<p> -The old <code>image/ycbcr</code> package has been folded, with some -renamings, into the -<a href="/pkg/image/"><code>image</code></a> -and -<a href="/pkg/image/color/"><code>image/color</code></a> -packages. -</p> - -<p> -The old <code>image.ColorImage</code> type is still in the <code>image</code> -package but has been renamed -<a href="/pkg/image/#Uniform"><code>image.Uniform</code></a>, -while <code>image.Tiled</code> has been removed. -</p> - -<p> -This table lists the renamings. -</p> - -<table class="codetable" frame="border" summary="image renames"> -<colgroup align="left" width="50%"></colgroup> -<colgroup align="left" width="50%"></colgroup> -<tr> -<th align="left">Old</th> -<th align="left">New</th> -</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>image.Color</td> <td>color.Color</td></tr> -<tr><td>image.ColorModel</td> <td>color.Model</td></tr> -<tr><td>image.ColorModelFunc</td> <td>color.ModelFunc</td></tr> -<tr><td>image.PalettedColorModel</td> <td>color.Palette</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>image.RGBAColor</td> <td>color.RGBA</td></tr> -<tr><td>image.RGBA64Color</td> <td>color.RGBA64</td></tr> -<tr><td>image.NRGBAColor</td> <td>color.NRGBA</td></tr> -<tr><td>image.NRGBA64Color</td> <td>color.NRGBA64</td></tr> -<tr><td>image.AlphaColor</td> <td>color.Alpha</td></tr> -<tr><td>image.Alpha16Color</td> <td>color.Alpha16</td></tr> -<tr><td>image.GrayColor</td> <td>color.Gray</td></tr> -<tr><td>image.Gray16Color</td> <td>color.Gray16</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>image.RGBAColorModel</td> <td>color.RGBAModel</td></tr> -<tr><td>image.RGBA64ColorModel</td> <td>color.RGBA64Model</td></tr> -<tr><td>image.NRGBAColorModel</td> <td>color.NRGBAModel</td></tr> -<tr><td>image.NRGBA64ColorModel</td> <td>color.NRGBA64Model</td></tr> -<tr><td>image.AlphaColorModel</td> <td>color.AlphaModel</td></tr> -<tr><td>image.Alpha16ColorModel</td> <td>color.Alpha16Model</td></tr> -<tr><td>image.GrayColorModel</td> <td>color.GrayModel</td></tr> -<tr><td>image.Gray16ColorModel</td> <td>color.Gray16Model</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>ycbcr.RGBToYCbCr</td> <td>color.RGBToYCbCr</td></tr> -<tr><td>ycbcr.YCbCrToRGB</td> <td>color.YCbCrToRGB</td></tr> -<tr><td>ycbcr.YCbCrColorModel</td> <td>color.YCbCrModel</td></tr> -<tr><td>ycbcr.YCbCrColor</td> <td>color.YCbCr</td></tr> -<tr><td>ycbcr.YCbCr</td> <td>image.YCbCr</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>ycbcr.SubsampleRatio444</td> <td>image.YCbCrSubsampleRatio444</td></tr> -<tr><td>ycbcr.SubsampleRatio422</td> <td>image.YCbCrSubsampleRatio422</td></tr> -<tr><td>ycbcr.SubsampleRatio420</td> <td>image.YCbCrSubsampleRatio420</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>image.ColorImage</td> <td>image.Uniform</td></tr> -</table> - -<p> -The image package's <code>New</code> functions -(<a href="/pkg/image/#NewRGBA"><code>NewRGBA</code></a>, -<a href="/pkg/image/#NewRGBA64"><code>NewRGBA64</code></a>, etc.) -take an <a href="/pkg/image/#Rectangle"><code>image.Rectangle</code></a> as an argument -instead of four integers. -</p> - -<p> -Finally, there are new predefined <code>color.Color</code> variables -<a href="/pkg/image/color/#Black"><code>color.Black</code></a>, -<a href="/pkg/image/color/#White"><code>color.White</code></a>, -<a href="/pkg/image/color/#Opaque"><code>color.Opaque</code></a> -and -<a href="/pkg/image/color/#Transparent"><code>color.Transparent</code></a>. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update almost all code affected by the change. -</p> - -<h3 id="log_syslog">The log/syslog package</h3> - -<p> -In Go 1, the <a href="/pkg/log/syslog/#NewLogger"><code>syslog.NewLogger</code></a> -function returns an error as well as a <code>log.Logger</code>. -</p> - -<p> -<em>Updating</em>: -What little code is affected will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="mime">The mime package</h3> - -<p> -In Go 1, the <a href="/pkg/mime/#FormatMediaType"><code>FormatMediaType</code></a> function -of the <code>mime</code> package has been simplified to make it -consistent with -<a href="/pkg/mime/#ParseMediaType"><code>ParseMediaType</code></a>. -It now takes <code>"text/html"</code> rather than <code>"text"</code> and <code>"html"</code>. -</p> - -<p> -<em>Updating</em>: -What little code is affected will be caught by the compiler and must be updated by hand. -</p> - -<h3 id="net">The net package</h3> - -<p> -In Go 1, the various <code>SetTimeout</code>, -<code>SetReadTimeout</code>, and <code>SetWriteTimeout</code> methods -have been replaced with -<a href="/pkg/net/#IPConn.SetDeadline"><code>SetDeadline</code></a>, -<a href="/pkg/net/#IPConn.SetReadDeadline"><code>SetReadDeadline</code></a>, and -<a href="/pkg/net/#IPConn.SetWriteDeadline"><code>SetWriteDeadline</code></a>, -respectively. Rather than taking a timeout value in nanoseconds that -apply to any activity on the connection, the new methods set an -absolute deadline (as a <code>time.Time</code> value) after which -reads and writes will time out and no longer block. -</p> - -<p> -There are also new functions -<a href="/pkg/net/#DialTimeout"><code>net.DialTimeout</code></a> -to simplify timing out dialing a network address and -<a href="/pkg/net/#ListenMulticastUDP"><code>net.ListenMulticastUDP</code></a> -to allow multicast UDP to listen concurrently across multiple listeners. -The <code>net.ListenMulticastUDP</code> function replaces the old -<code>JoinGroup</code> and <code>LeaveGroup</code> methods. -</p> - -<p> -<em>Updating</em>: -Code that uses the old methods will fail to compile and must be updated by hand. -The semantic change makes it difficult for the fix tool to update automatically. -</p> - -<h3 id="os">The os package</h3> - -<p> -The <code>Time</code> function has been removed; callers should use -the <a href="/pkg/time/#Time"><code>Time</code></a> type from the -<code>time</code> package. -</p> - -<p> -The <code>Exec</code> function has been removed; callers should use -<code>Exec</code> from the <code>syscall</code> package, where available. -</p> - -<p> -The <code>ShellExpand</code> function has been renamed to <a -href="/pkg/os/#ExpandEnv"><code>ExpandEnv</code></a>. -</p> - -<p> -The <a href="/pkg/os/#NewFile"><code>NewFile</code></a> function -now takes a <code>uintptr</code> fd, instead of an <code>int</code>. -The <a href="/pkg/os/#File.Fd"><code>Fd</code></a> method on files now -also returns a <code>uintptr</code>. -</p> - -<p> -There are no longer error constants such as <code>EINVAL</code> -in the <code>os</code> package, since the set of values varied with -the underlying operating system. There are new portable functions like -<a href="/pkg/os/#IsPermission"><code>IsPermission</code></a> -to test common error properties, plus a few new error values -with more Go-like names, such as -<a href="/pkg/os/#ErrPermission"><code>ErrPermission</code></a> -and -<a href="/pkg/os/#ErrNoEnv"><code>ErrNoEnv</code></a>. -</p> - -<p> -The <code>Getenverror</code> function has been removed. To distinguish -between a non-existent environment variable and an empty string, -use <a href="/pkg/os/#Environ"><code>os.Environ</code></a> or -<a href="/pkg/syscall/#Getenv"><code>syscall.Getenv</code></a>. -</p> - - -<p> -The <a href="/pkg/os/#Process.Wait"><code>Process.Wait</code></a> method has -dropped its option argument and the associated constants are gone -from the package. -Also, the function <code>Wait</code> is gone; only the method of -the <code>Process</code> type persists. -</p> - -<p> -The <code>Waitmsg</code> type returned by -<a href="/pkg/os/#Process.Wait"><code>Process.Wait</code></a> -has been replaced with a more portable -<a href="/pkg/os/#ProcessState"><code>ProcessState</code></a> -type with accessor methods to recover information about the -process. -Because of changes to <code>Wait</code>, the <code>ProcessState</code> -value always describes an exited process. -Portability concerns simplified the interface in other ways, but the values returned by the -<a href="/pkg/os/#ProcessState.Sys"><code>ProcessState.Sys</code></a> and -<a href="/pkg/os/#ProcessState.SysUsage"><code>ProcessState.SysUsage</code></a> -methods can be type-asserted to underlying system-specific data structures such as -<a href="/pkg/syscall/#WaitStatus"><code>syscall.WaitStatus</code></a> and -<a href="/pkg/syscall/#Rusage"><code>syscall.Rusage</code></a> on Unix. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will drop a zero argument to <code>Process.Wait</code>. -All other changes will be caught by the compiler and must be updated by hand. -</p> - -<h4 id="os_fileinfo">The os.FileInfo type</h4> - -<p> -Go 1 redefines the <a href="/pkg/os/#FileInfo"><code>os.FileInfo</code></a> type, -changing it from a struct to an interface: -</p> - -<pre> - type FileInfo interface { - Name() string // base name of the file - Size() int64 // length in bytes - Mode() FileMode // file mode bits - ModTime() time.Time // modification time - IsDir() bool // abbreviation for Mode().IsDir() - Sys() interface{} // underlying data source (can return nil) - } -</pre> - -<p> -The file mode information has been moved into a subtype called -<a href="/pkg/os/#FileMode"><code>os.FileMode</code></a>, -a simple integer type with <code>IsDir</code>, <code>Perm</code>, and <code>String</code> -methods. -</p> - -<p> -The system-specific details of file modes and properties such as (on Unix) -i-number have been removed from <code>FileInfo</code> altogether. -Instead, each operating system's <code>os</code> package provides an -implementation of the <code>FileInfo</code> interface, which -has a <code>Sys</code> method that returns the -system-specific representation of file metadata. -For instance, to discover the i-number of a file on a Unix system, unpack -the <code>FileInfo</code> like this: -</p> - -<pre> - fi, err := os.Stat("hello.go") - if err != nil { - log.Fatal(err) - } - // Check that it's a Unix file. - unixStat, ok := fi.Sys().(*syscall.Stat_t) - if !ok { - log.Fatal("hello.go: not a Unix file") - } - fmt.Printf("file i-number: %d\n", unixStat.Ino) -</pre> - -<p> -Assuming (which is unwise) that <code>"hello.go"</code> is a Unix file, -the i-number expression could be contracted to -</p> - -<pre> - fi.Sys().(*syscall.Stat_t).Ino -</pre> - -<p> -The vast majority of uses of <code>FileInfo</code> need only the methods -of the standard interface. -</p> - -<p> -The <code>os</code> package no longer contains wrappers for the POSIX errors -such as <code>ENOENT</code>. -For the few programs that need to verify particular error conditions, there are -now the boolean functions -<a href="/pkg/os/#IsExist"><code>IsExist</code></a>, -<a href="/pkg/os/#IsNotExist"><code>IsNotExist</code></a> -and -<a href="/pkg/os/#IsPermission"><code>IsPermission</code></a>. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/os\.Open/` `/}/`}} ---> f, err := os.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600) - if os.IsExist(err) { - log.Printf("%s already exists", name) - }</pre> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update code that uses the old equivalent of the current <code>os.FileInfo</code> -and <code>os.FileMode</code> API. -Code that needs system-specific file details will need to be updated by hand. -Code that uses the old POSIX error values from the <code>os</code> package -will fail to compile and will also need to be updated by hand. -</p> - -<h3 id="os_signal">The os/signal package</h3> - -<p> -The <code>os/signal</code> package in Go 1 replaces the -<code>Incoming</code> function, which returned a channel -that received all incoming signals, -with the selective <code>Notify</code> function, which asks -for delivery of specific signals on an existing channel. -</p> - -<p> -<em>Updating</em>: -Code must be updated by hand. -A literal translation of -</p> -<pre> -c := signal.Incoming() -</pre> -<p> -is -</p> -<pre> -c := make(chan os.Signal) -signal.Notify(c) // ask for all signals -</pre> -<p> -but most code should list the specific signals it wants to handle instead: -</p> -<pre> -c := make(chan os.Signal) -signal.Notify(c, syscall.SIGHUP, syscall.SIGQUIT) -</pre> - -<h3 id="path_filepath">The path/filepath package</h3> - -<p> -In Go 1, the <a href="/pkg/path/filepath/#Walk"><code>Walk</code></a> function of the -<code>path/filepath</code> package -has been changed to take a function value of type -<a href="/pkg/path/filepath/#WalkFunc"><code>WalkFunc</code></a> -instead of a <code>Visitor</code> interface value. -<code>WalkFunc</code> unifies the handling of both files and directories. -</p> - -<pre> - type WalkFunc func(path string, info os.FileInfo, err error) error -</pre> - -<p> -The <code>WalkFunc</code> function will be called even for files or directories that could not be opened; -in such cases the error argument will describe the failure. -If a directory's contents are to be skipped, -the function should return the value <a href="/pkg/path/filepath/#variables"><code>filepath.SkipDir</code></a> -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/STARTWALK/` `/ENDWALK/`}} ---> markFn := func(path string, info os.FileInfo, err error) error { - if path == "pictures" { <span class="comment">// Will skip walking of directory pictures and its contents.</span> - return filepath.SkipDir - } - if err != nil { - return err - } - log.Println(path) - return nil - } - err := filepath.Walk(".", markFn) - if err != nil { - log.Fatal(err) - }</pre> - -<p> -<em>Updating</em>: -The change simplifies most code but has subtle consequences, so affected programs -will need to be updated by hand. -The compiler will catch code using the old interface. -</p> - -<h3 id="regexp">The regexp package</h3> - -<p> -The <a href="/pkg/regexp/"><code>regexp</code></a> package has been rewritten. -It has the same interface but the specification of the regular expressions -it supports has changed from the old "egrep" form to that of -<a href="http://code.google.com/p/re2/">RE2</a>. -</p> - -<p> -<em>Updating</em>: -Code that uses the package should have its regular expressions checked by hand. -</p> - -<h3 id="runtime">The runtime package</h3> - -<p> -In Go 1, much of the API exported by package -<code>runtime</code> has been removed in favor of -functionality provided by other packages. -Code using the <code>runtime.Type</code> interface -or its specific concrete type implementations should -now use package <a href="/pkg/reflect/"><code>reflect</code></a>. -Code using <code>runtime.Semacquire</code> or <code>runtime.Semrelease</code> -should use channels or the abstractions in package <a href="/pkg/sync/"><code>sync</code></a>. -The <code>runtime.Alloc</code>, <code>runtime.Free</code>, -and <code>runtime.Lookup</code> functions, an unsafe API created for -debugging the memory allocator, have no replacement. -</p> - -<p> -Before, <code>runtime.MemStats</code> was a global variable holding -statistics about memory allocation, and calls to <code>runtime.UpdateMemStats</code> -ensured that it was up to date. -In Go 1, <code>runtime.MemStats</code> is a struct type, and code should use -<a href="/pkg/runtime/#ReadMemStats"><code>runtime.ReadMemStats</code></a> -to obtain the current statistics. -</p> - -<p> -The package adds a new function, -<a href="/pkg/runtime/#NumCPU"><code>runtime.NumCPU</code></a>, that returns the number of CPUs available -for parallel execution, as reported by the operating system kernel. -Its value can inform the setting of <code>GOMAXPROCS</code>. -The <code>runtime.Cgocalls</code> and <code>runtime.Goroutines</code> functions -have been renamed to <code>runtime.NumCgoCall</code> and <code>runtime.NumGoroutine</code>. -</p> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update code for the function renamings. -Other code will need to be updated by hand. -</p> - -<h3 id="strconv">The strconv package</h3> - -<p> -In Go 1, the -<a href="/pkg/strconv/"><code>strconv</code></a> -package has been significantly reworked to make it more Go-like and less C-like, -although <code>Atoi</code> lives on (it's similar to -<code>int(ParseInt(x, 10, 0))</code>, as does -<code>Itoa(x)</code> (<code>FormatInt(int64(x), 10)</code>). -There are also new variants of some of the functions that append to byte slices rather than -return strings, to allow control over allocation. -</p> - -<p> -This table summarizes the renamings; see the -<a href="/pkg/strconv/">package documentation</a> -for full details. -</p> - -<table class="codetable" frame="border" summary="strconv renames"> -<colgroup align="left" width="50%"></colgroup> -<colgroup align="left" width="50%"></colgroup> -<tr> -<th align="left">Old call</th> -<th align="left">New call</th> -</tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Atob(x)</td> <td>ParseBool(x)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Atof32(x)</td> <td>ParseFloat(x, 32)§</td></tr> -<tr><td>Atof64(x)</td> <td>ParseFloat(x, 64)</td></tr> -<tr><td>AtofN(x, n)</td> <td>ParseFloat(x, n)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Atoi(x)</td> <td>Atoi(x)</td></tr> -<tr><td>Atoi(x)</td> <td>ParseInt(x, 10, 0)§</td></tr> -<tr><td>Atoi64(x)</td> <td>ParseInt(x, 10, 64)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Atoui(x)</td> <td>ParseUint(x, 10, 0)§</td></tr> -<tr><td>Atoui64(x)</td> <td>ParseUint(x, 10, 64)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Btoi64(x, b)</td> <td>ParseInt(x, b, 64)</td></tr> -<tr><td>Btoui64(x, b)</td> <td>ParseUint(x, b, 64)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Btoa(x)</td> <td>FormatBool(x)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Ftoa32(x, f, p)</td> <td>FormatFloat(float64(x), f, p, 32)</td></tr> -<tr><td>Ftoa64(x, f, p)</td> <td>FormatFloat(x, f, p, 64)</td></tr> -<tr><td>FtoaN(x, f, p, n)</td> <td>FormatFloat(x, f, p, n)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Itoa(x)</td> <td>Itoa(x)</td></tr> -<tr><td>Itoa(x)</td> <td>FormatInt(int64(x), 10)</td></tr> -<tr><td>Itoa64(x)</td> <td>FormatInt(x, 10)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Itob(x, b)</td> <td>FormatInt(int64(x), b)</td></tr> -<tr><td>Itob64(x, b)</td> <td>FormatInt(x, b)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Uitoa(x)</td> <td>FormatUint(uint64(x), 10)</td></tr> -<tr><td>Uitoa64(x)</td> <td>FormatUint(x, 10)</td></tr> -<tr> -<td colspan="2"><hr></td> -</tr> -<tr><td>Uitob(x, b)</td> <td>FormatUint(uint64(x), b)</td></tr> -<tr><td>Uitob64(x, b)</td> <td>FormatUint(x, b)</td></tr> -</table> - -<p> -<em>Updating</em>: -Running <code>go</code> <code>fix</code> will update almost all code affected by the change. -<br> -§ <code>Atoi</code> persists but <code>Atoui</code> and <code>Atof32</code> do not, so -they may require -a cast that must be added by hand; the <code>go</code> <code>fix</code> tool will warn about it. -</p> - - -<h3 id="templates">The template packages</h3> - -<p> -The <code>template</code> and <code>exp/template/html</code> packages have moved to -<a href="/pkg/text/template/"><code>text/template</code></a> and -<a href="/pkg/html/template/"><code>html/template</code></a>. -More significant, the interface to these packages has been simplified. -The template language is the same, but the concept of "template set" is gone -and the functions and methods of the packages have changed accordingly, -often by elimination. -</p> - -<p> -Instead of sets, a <code>Template</code> object -may contain multiple named template definitions, -in effect constructing -name spaces for template invocation. -A template can invoke any other template associated with it, but only those -templates associated with it. -The simplest way to associate templates is to parse them together, something -made easier with the new structure of the packages. -</p> - -<p> -<em>Updating</em>: -The imports will be updated by fix tool. -Single-template uses will be otherwise be largely unaffected. -Code that uses multiple templates in concert will need to be updated by hand. -The <a href="/pkg/text/template/#examples">examples</a> in -the documentation for <code>text/template</code> can provide guidance. -</p> - -<h3 id="testing">The testing package</h3> - -<p> -The testing package has a type, <code>B</code>, passed as an argument to benchmark functions. -In Go 1, <code>B</code> has new methods, analogous to those of <code>T</code>, enabling -logging and failure reporting. -</p> - -<pre><!--{{code "/doc/progs/go1.go" `/func.*Benchmark/` `/^}/`}} --->func BenchmarkSprintf(b *testing.B) { - <span class="comment">// Verify correctness before running benchmark.</span> - b.StopTimer() - got := fmt.Sprintf("%x", 23) - const expect = "17" - if expect != got { - b.Fatalf("expected %q; got %q", expect, got) - } - b.StartTimer() - for i := 0; i < b.N; i++ { - fmt.Sprintf("%x", 23) - } -}</pre> - -<p> -<em>Updating</em>: -Existing code is unaffected, although benchmarks that use <code>println</code> -or <code>panic</code> should be updated to use the new methods. -</p> - -<h3 id="testing_script">The testing/script package</h3> - -<p> -The testing/script package has been deleted. It was a dreg. -</p> - -<p> -<em>Updating</em>: -No code is likely to be affected. -</p> - -<h3 id="unsafe">The unsafe package</h3> - -<p> -In Go 1, the functions -<code>unsafe.Typeof</code>, <code>unsafe.Reflect</code>, -<code>unsafe.Unreflect</code>, <code>unsafe.New</code>, and -<code>unsafe.NewArray</code> have been removed; -they duplicated safer functionality provided by -package <a href="/pkg/reflect/"><code>reflect</code></a>. -</p> - -<p> -<em>Updating</em>: -Code using these functions must be rewritten to use -package <a href="/pkg/reflect/"><code>reflect</code></a>. -The changes to <a href="http://code.google.com/p/go/source/detail?r=2646dc956207">encoding/gob</a> and the <a href="http://code.google.com/p/goprotobuf/source/detail?r=5340ad310031">protocol buffer library</a> -may be helpful as examples. -</p> - -<h3 id="url">The url package</h3> - -<p> -In Go 1 several fields from the <a href="/pkg/net/url/#URL"><code>url.URL</code></a> type -were removed or replaced. -</p> - -<p> -The <a href="/pkg/net/url/#URL.String"><code>String</code></a> method now -predictably rebuilds an encoded URL string using all of <code>URL</code>'s -fields as necessary. The resulting string will also no longer have -passwords escaped. -</p> - -<p> -The <code>Raw</code> field has been removed. In most cases the <code>String</code> -method may be used in its place. -</p> - -<p> -The old <code>RawUserinfo</code> field is replaced by the <code>User</code> -field, of type <a href="/pkg/net/url/#Userinfo"><code>*net.Userinfo</code></a>. -Values of this type may be created using the new <a href="/pkg/net/url/#User"><code>net.User</code></a> -and <a href="/pkg/net/url/#UserPassword"><code>net.UserPassword</code></a> -functions. The <code>EscapeUserinfo</code> and <code>UnescapeUserinfo</code> -functions are also gone. -</p> - -<p> -The <code>RawAuthority</code> field has been removed. The same information is -available in the <code>Host</code> and <code>User</code> fields. -</p> - -<p> -The <code>RawPath</code> field and the <code>EncodedPath</code> method have -been removed. The path information in rooted URLs (with a slash following the -schema) is now available only in decoded form in the <code>Path</code> field. -Occasionally, the encoded data may be required to obtain information that -was lost in the decoding process. These cases must be handled by accessing -the data the URL was built from. -</p> - -<p> -URLs with non-rooted paths, such as <code>"mailto:dev@golang.org?subject=Hi"</code>, -are also handled differently. The <code>OpaquePath</code> boolean field has been -removed and a new <code>Opaque</code> string field introduced to hold the encoded -path for such URLs. In Go 1, the cited URL parses as: -</p> - -<pre> - URL{ - Scheme: "mailto", - Opaque: "dev@golang.org", - RawQuery: "subject=Hi", - } -</pre> - -<p> -A new <a href="/pkg/net/url/#URL.RequestURI"><code>RequestURI</code></a> method was -added to <code>URL</code>. -</p> - -<p> -The <code>ParseWithReference</code> function has been renamed to <code>ParseWithFragment</code>. -</p> - -<p> -<em>Updating</em>: -Code that uses the old fields will fail to compile and must be updated by hand. -The semantic changes make it difficult for the fix tool to update automatically. -</p> - -<h2 id="cmd_go">The go command</h2> - -<p> -Go 1 introduces the <a href="/cmd/go/">go command</a>, a tool for fetching, -building, and installing Go packages and commands. The <code>go</code> command -does away with makefiles, instead using Go source code to find dependencies and -determine build conditions. Most existing Go programs will no longer require -makefiles to be built. -</p> - -<p> -See <a href="/doc/code.html">How to Write Go Code</a> for a primer on the -<code>go</code> command and the <a href="/cmd/go/">go command documentation</a> -for the full details. -</p> - -<p> -<em>Updating</em>: -Projects that depend on the Go project's old makefile-based build -infrastructure (<code>Make.pkg</code>, <code>Make.cmd</code>, and so on) should -switch to using the <code>go</code> command for building Go code and, if -necessary, rewrite their makefiles to perform any auxiliary build tasks. -</p> - -<h2 id="cmd_cgo">The cgo command</h2> - -<p> -In Go 1, the <a href="/cmd/cgo">cgo command</a> -uses a different <code>_cgo_export.h</code> -file, which is generated for packages containing <code>//export</code> lines. -The <code>_cgo_export.h</code> file now begins with the C preamble comment, -so that exported function definitions can use types defined there. -This has the effect of compiling the preamble multiple times, so a -package using <code>//export</code> must not put function definitions -or variable initializations in the C preamble. -</p> - -<h2 id="releases">Packaged releases</h2> - -<p> -One of the most significant changes associated with Go 1 is the availability -of prepackaged, downloadable distributions. -They are available for many combinations of architecture and operating system -(including Windows) and the list will grow. -Installation details are described on the -<a href="/doc/install">Getting Started</a> page, while -the distributions themselves are listed on the -<a href="http://code.google.com/p/go/downloads/list">downloads page</a>. - - -</div> - -<div id="footer"> -Build version go1.0.1.<br> -A link <a href="http://code.google.com/policies.html#restrictions">noted</a>, -and then, coming up on the very next line, we will -find yet another link, link 3.0 if you will, -after a few more words <a href="/LINK">link text</a>.<br> -<a href="/doc/tos.html">Terms of Service</a> | -<a href="http://www.google.com/intl/en/privacy/privacy-policy.html">Privacy Policy</a> -</div> - -<script type="text/javascript"> -(function() { - var ga = document.createElement("script"); ga.type = "text/javascript"; ga.async = true; - ga.src = ("https:" == document.location.protocol ? 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