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clean up a TODO
R=rsc DELTA=45 (28 added, 4 deleted, 13 changed) OCL=32673 CL=32675
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@ -1,6 +1,14 @@
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<h2 id="introduction">Introduction</h2>
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<p>
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Go is a new language. Although it's in the C family of languages
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it has some unusual properties that make effective Go programs
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different in character from programs in C, C++, or Java.
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To write Go well, it's important to understand its properties
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and idioms.
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</p>
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<p>
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This document gives tips for writing clear, idiomatic Go code
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and points out common mistakes.
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@ -287,11 +295,11 @@ A comment can introduce a group of related constants or variables.
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</p>
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<pre>
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// Flags to Open wrapping those of the underlying system.
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// Flags to Open, wrapping those of the underlying system.
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// Not all flags may be implemented on a given system.
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const (
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O_RDONLY = syscall.O_RDONLY; // open the file read-only.
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O_WRONLY = syscall.O_WRONLY; // open the file write-only.
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O_RDONLY = syscall.O_RDONLY; // Open file read-only.
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O_WRONLY = syscall.O_WRONLY; // Open file write-only.
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...
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)
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</pre>
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@ -303,9 +311,9 @@ a mutex.
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</p>
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<pre>
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// Variables protected by counterLock.
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// Variables protected by countLock.
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var (
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counterLock sync.Mutex;
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countLock sync.Mutex;
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inputCount uint32;
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outputCount uint32;
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errorCount uint32;
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@ -357,9 +365,8 @@ the buffered <code>Reader</code> is <code>bufio.Reader</code>, not <code>bufio.B
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Similarly, <code>once.Do</code> is as precise and evocative as
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<code>once.DoOrWaitUntilDone</code>, and <code>once.Do(f)</code> reads
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better than <code>once.DoOrWaitUntilDone(f)</code>.
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Contrary to popular belief, encoding small essays into
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function names does not make it possible
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to use them without documentation.
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Encoding small essays into function names is not Go style;
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clear names with good documentation is.
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</p>
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<h3 id="interfacers">Use the -er convention for interface names</h3>
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@ -564,24 +571,41 @@ codeUsing(f);
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<h3 id="error-context">Return structured errors</h3>
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Implementations of <code>os.Error</code>s should
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describe the error but also include context.
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Implementations of <code>os.Error</code> should
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describe the error and provide context.
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For example, <code>os.Open</code> returns an <code>os.PathError</code>:
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<a href="/src/pkg/os/file.go">/src/pkg/os/file.go</a>:
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<pre>
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XXX definition of PathError and .String
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// PathError records an error and the operation and
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// file path that caused it.
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type PathError struct {
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Op string;
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Path string;
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Error Error;
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}
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func (e *PathError) String() string {
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return e.Op + " " + e.Path + ": " + e.Error.String();
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}
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</pre>
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<code>PathError</code>'s <code>String</code> formats
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the error nicely and is the usual way the error gets used.
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the error nicely, including the operation and file name
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tha failed; just printing the error generates a
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message, such as
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<pre>
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open /etc/passwx: no such file or directory
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</pre>
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that is useful even if printed far from the call that
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triggered it.
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</p>
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<p>
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Callers that care about the precise error details can
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use a type switch or a type guard to look for specific
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errors and then extract details.
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<pre>
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XXX example here - MkdirAll
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</pre>
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errors and extract details.
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</p>
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<h2 id="types">Programmer-defined types</h2>
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