qbit/go
1
0
Fork 0
mirror of https://github.com/golang/go synced 2024-11-25 06:57:58 -07:00
Code Releases Activity

doc: fix typos in laws_of_reflection article, add copyright notice.

Browse Source 
Update #2547.

R=golang-dev, minux.ma, r, r, adg
CC=golang-dev
https://golang.org/cl/5755051
This commit is contained in:
Johan Euphrosine 2012-03-07 11:24:00 +11:00 committed by Andrew Gerrand
parent 7a3c6c950b
commit 26dc17ce78
4 changed files with 34 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
doc/articles/laws_of_reflection.html
View File

@ -216,7 +216,7 @@ At the basic level, reflection is just a mechanism to examine the
type and value pair stored inside an interface variable. To get type and value pair stored inside an interface variable. To get
started, there are two types we need to know about in started, there are two types we need to know about in
<a href="http://golang.org/pkg/reflect">package reflect</a>: <a href="http://golang.org/pkg/reflect">package reflect</a>:
<a href="http://golang.org/pkg/reflect/#Type">Type</a>and <a href="http://golang.org/pkg/reflect/#Type">Type</a> and
<a href="http://golang.org/pkg/reflect/#Value">Value</a>. Those two types <a href="http://golang.org/pkg/reflect/#Value">Value</a>. Those two types
give access to the contents of an interface variable, and two give access to the contents of an interface variable, and two
simple functions, called <code>reflect.TypeOf</code> and simple functions, called <code>reflect.TypeOf</code> and
@ -356,7 +356,7 @@ reflection object contains a value of a user-defined integer type,
as in as in
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f3/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f3/` `/STOP/`}}
--> type MyInt int --> type MyInt int
var x MyInt = 7 var x MyInt = 7
v := reflect.ValueOf(x)</pre> v := reflect.ValueOf(x)</pre>
@ -395,7 +395,7 @@ func (v Value) Interface() interface{}
As a consequence we can say As a consequence we can say
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f3b/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f3b/` `/STOP/`}}
--> y := v.Interface().(float64) // y will have type float64. --> y := v.Interface().(float64) // y will have type float64.
fmt.Println(y)</pre> fmt.Println(y)</pre>
@ -415,7 +415,7 @@ the <code>Interface</code> method to the formatted print
routine: routine:
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f3c/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f3c/` `/STOP/`}}
--> fmt.Println(v.Interface())</pre> --> fmt.Println(v.Interface())</pre>
<p> <p>
@ -518,7 +518,7 @@ determined by whether the reflection object holds the original
item. When we say item. When we say
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f6/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f6/` `/STOP/`}}
--> var x float64 = 3.4 --> var x float64 = 3.4
v := reflect.ValueOf(x)</pre> v := reflect.ValueOf(x)</pre>
@ -577,7 +577,7 @@ and then create a reflection value that points to it, called
<code>p</code>. <code>p</code>.
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f7/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f7/` `/STOP/`}}
--> var x float64 = 3.4 --> var x float64 = 3.4
p := reflect.ValueOf(&amp;x) // Note: take the address of x. p := reflect.ValueOf(&amp;x) // Note: take the address of x.
fmt.Println(&#34;type of p:&#34;, p.Type()) fmt.Println(&#34;type of p:&#34;, p.Type())
@ -601,7 +601,7 @@ and save the result in a reflection <code>Value</code> called
<code>v</code>: <code>v</code>:
</p> </p>
<pre><!--{{code "progs/interface2.go" `/START f7b/` `/START/`}} <pre><!--{{code "progs/interface2.go" `/START f7b/` `/STOP/`}}
--> v := p.Elem() --> v := p.Elem()
fmt.Println(&#34;settability of v:&#34;, v.CanSet())</pre> fmt.Println(&#34;settability of v:&#34;, v.CanSet())</pre>
@ -676,10 +676,7 @@ objects.
f := s.Field(i) f := s.Field(i)
fmt.Printf(&#34;%d: %s %s = %v\n&#34;, i, fmt.Printf(&#34;%d: %s %s = %v\n&#34;, i,
typeOfT.Field(i).Name, f.Type(), f.Interface()) typeOfT.Field(i).Name, f.Type(), f.Interface())
} }</pre>
s.Field(0).SetInt(77)
s.Field(1).SetString(&#34;Sunset Strip&#34;)
fmt.Println(&#34;t is now&#34;, t)</pre>
<p> <p>
The output of this program is The output of this program is

14
doc/articles/laws_of_reflection.tmpl
View File

@ -184,7 +184,7 @@ At the basic level, reflection is just a mechanism to examine the
type and value pair stored inside an interface variable. To get type and value pair stored inside an interface variable. To get
started, there are two types we need to know about in started, there are two types we need to know about in
<a href="http://golang.org/pkg/reflect">package reflect</a>: <a href="http://golang.org/pkg/reflect">package reflect</a>:
<a href="http://golang.org/pkg/reflect/#Type">Type</a>and <a href="http://golang.org/pkg/reflect/#Type">Type</a> and
<a href="http://golang.org/pkg/reflect/#Value">Value</a>. Those two types <a href="http://golang.org/pkg/reflect/#Value">Value</a>. Those two types
give access to the contents of an interface variable, and two give access to the contents of an interface variable, and two
simple functions, called <code>reflect.TypeOf</code> and simple functions, called <code>reflect.TypeOf</code> and
@ -301,7 +301,7 @@ reflection object contains a value of a user-defined integer type,
as in as in
</p> </p>
{{code "progs/interface2.go" `/START f3/` `/START/`}} {{code "progs/interface2.go" `/START f3/` `/STOP/`}}
<p> <p>
the <code>Kind</code> of <code>v</code> is still the <code>Kind</code> of <code>v</code> is still
@ -337,7 +337,7 @@ func (v Value) Interface() interface{}
As a consequence we can say As a consequence we can say
</p> </p>
{{code "progs/interface2.go" `/START f3b/` `/START/`}} {{code "progs/interface2.go" `/START f3b/` `/STOP/`}}
<p> <p>
to print the <code>float64</code> value represented by the to print the <code>float64</code> value represented by the
@ -355,7 +355,7 @@ the <code>Interface</code> method to the formatted print
routine: routine:
</p> </p>
{{code "progs/interface2.go" `/START f3c/` `/START/`}} {{code "progs/interface2.go" `/START f3c/` `/STOP/`}}
<p> <p>
(Why not <code>fmt.Println(v)</code>? Because <code>v</code> is a (Why not <code>fmt.Println(v)</code>? Because <code>v</code> is a
@ -450,7 +450,7 @@ determined by whether the reflection object holds the original
item. When we say item. When we say
</p> </p>
{{code "progs/interface2.go" `/START f6/` `/START/`}} {{code "progs/interface2.go" `/START f6/` `/STOP/`}}
<p> <p>
we pass a <em>copy</em> of <code>x</code> to we pass a <em>copy</em> of <code>x</code> to
@ -506,7 +506,7 @@ and then create a reflection value that points to it, called
<code>p</code>. <code>p</code>.
</p> </p>
{{code "progs/interface2.go" `/START f7/` `/START/`}} {{code "progs/interface2.go" `/START f7/` `/STOP/`}}
<p> <p>
The output so far is The output so far is
@ -526,7 +526,7 @@ and save the result in a reflection <code>Value</code> called
<code>v</code>: <code>v</code>:
</p> </p>
{{code "progs/interface2.go" `/START f7b/` `/START/`}} {{code "progs/interface2.go" `/START f7b/` `/STOP/`}}
<p> <p>
Now <code>v</code> is a settable reflection object, as the output Now <code>v</code> is a settable reflection object, as the output

6
doc/progs/interface.go
View File

@ -1,3 +1,9 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file contains the code snippets included in "The Laws of Reflection."
package main package main
import ( import (

13
doc/progs/interface2.go
View File

@ -1,3 +1,9 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// This file contains the code snippets included in "The Laws of Reflection."
package main package main
import ( import (
@ -39,11 +45,14 @@ func f3() {
type MyInt int type MyInt int
var x MyInt = 7 var x MyInt = 7
v := reflect.ValueOf(x) v := reflect.ValueOf(x)
// STOP OMIT
// START f3b OMIT // START f3b OMIT
y := v.Interface().(float64) // y will have type float64. y := v.Interface().(float64) // y will have type float64.
fmt.Println(y) fmt.Println(y)
// STOP OMIT
// START f3c OMIT // START f3c OMIT
fmt.Println(v.Interface()) fmt.Println(v.Interface())
// STOP OMIT
// START f3d OMIT // START f3d OMIT
fmt.Printf("value is %7.1e\n", v.Interface()) fmt.Printf("value is %7.1e\n", v.Interface())
// STOP OMIT // STOP OMIT
@ -69,6 +78,7 @@ func f6() {
// START f6 OMIT // START f6 OMIT
var x float64 = 3.4 var x float64 = 3.4
v := reflect.ValueOf(x) v := reflect.ValueOf(x)
// STOP OMIT
// START f6b OMIT // START f6b OMIT
v.SetFloat(7.1) v.SetFloat(7.1)
// STOP OMIT // STOP OMIT
@ -80,9 +90,11 @@ func f7() {
p := reflect.ValueOf(&x) // Note: take the address of x. p := reflect.ValueOf(&x) // Note: take the address of x.
fmt.Println("type of p:", p.Type()) fmt.Println("type of p:", p.Type())
fmt.Println("settability of p:", p.CanSet()) fmt.Println("settability of p:", p.CanSet())
// STOP OMIT
// START f7b OMIT // START f7b OMIT
v := p.Elem() v := p.Elem()
fmt.Println("settability of v:", v.CanSet()) fmt.Println("settability of v:", v.CanSet())
// STOP OMIT
// START f7c OMIT // START f7c OMIT
v.SetFloat(7.1) v.SetFloat(7.1)
fmt.Println(v.Interface()) fmt.Println(v.Interface())
@ -104,6 +116,7 @@ func f8() {
fmt.Printf("%d: %s %s = %v\n", i, fmt.Printf("%d: %s %s = %v\n", i,
typeOfT.Field(i).Name, f.Type(), f.Interface()) typeOfT.Field(i).Name, f.Type(), f.Interface())
} }
// STOP OMIT
// START f8b OMIT // START f8b OMIT
s.Field(0).SetInt(77) s.Field(0).SetInt(77)
s.Field(1).SetString("Sunset Strip") s.Field(1).SetString("Sunset Strip")