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Diffstat (limited to 'content/go-fmt-your-code.article')
| -rw-r--r-- | content/go-fmt-your-code.article | 65 |
1 files changed, 33 insertions, 32 deletions
diff --git a/content/go-fmt-your-code.article b/content/go-fmt-your-code.article index 7b560d7..91d41f7 100644 --- a/content/go-fmt-your-code.article +++ b/content/go-fmt-your-code.article @@ -1,27 +1,28 @@ -go fmt your code +# go fmt your code 23 Jan 2013 Tags: gofix, gofmt, technical +Summary: [Gofmt](https://golang.org/cmd/gofmt/) is a tool that automatically formats Go source code. Andrew Gerrand -* Introduction +## Introduction -[[https://golang.org/cmd/gofmt/][Gofmt]] is a tool that automatically formats Go source code. +[Gofmt](https://golang.org/cmd/gofmt/) is a tool that automatically formats Go source code. Gofmt'd code is: -- easier to *write*: never worry about minor formatting concerns while hacking away, + - easier to **write**: never worry about minor formatting concerns while hacking away, -- easier to *read*: when all code looks the same you need not mentally convert - others' formatting style into something you can understand. + - easier to **read**: when all code looks the same you need not mentally convert + others' formatting style into something you can understand. -- easier to *maintain*: mechanical changes to the source don't cause unrelated - changes to the file's formatting; - diffs show only the real changes. + - easier to **maintain**: mechanical changes to the source don't cause unrelated + changes to the file's formatting; + diffs show only the real changes. -- *uncontroversial*: never have a debate about spacing or brace position ever again! + - **uncontroversial**: never have a debate about spacing or brace position ever again! -* Format your code +## Format your code We recently conducted a survey of Go packages in the wild and found that about 70% of them are formatted according to gofmt's rules. @@ -30,35 +31,35 @@ it would be great to close the gap. To format your code, you can use the gofmt tool directly: - gofmt -w yourcode.go + gofmt -w yourcode.go -Or you can use the "[[https://golang.org/cmd/go/#hdr-Run_gofmt_on_package_sources][go fmt]]" command: +Or you can use the "[go fmt](https://golang.org/cmd/go/#hdr-Run_gofmt_on_package_sources)" command: - go fmt path/to/your/package + go fmt path/to/your/package To help keep your code in the canonical style, the Go repository contains hooks for editors and version control systems that make it easy to run gofmt on your code. -For Vim users, the [[https://github.com/fatih/vim-go][Vim plugin for Go]] +For Vim users, the [Vim plugin for Go](https://github.com/fatih/vim-go) includes the :Fmt command that runs gofmt on the current buffer. -For emacs users, [[https://github.com/dominikh/go-mode.el][go-mode.el]] +For emacs users, [go-mode.el](https://github.com/dominikh/go-mode.el) provides a gofmt-before-save hook that can be installed by adding this line to your .emacs file: - (add-hook 'before-save-hook #'gofmt-before-save) + (add-hook 'before-save-hook #'gofmt-before-save) -For Eclipse or Sublime Text users, the [[https://github.com/GoClipse/goclipse][GoClipse]] -and [[https://github.com/DisposaBoy/GoSublime][GoSublime]] projects add +For Eclipse or Sublime Text users, the [GoClipse](https://github.com/GoClipse/goclipse) +and [GoSublime](https://github.com/DisposaBoy/GoSublime) projects add a gofmt facility to those editors. -And for Git aficionados, the [[https://github.com/golang/go/blob/release-branch.go1.1/misc/git/pre-commit][misc/git/pre-commit script]] +And for Git aficionados, the [misc/git/pre-commit script](https://github.com/golang/go/blob/release-branch.go1.1/misc/git/pre-commit) is a pre-commit hook that prevents incorrectly-formatted Go code from being committed. -If you use Mercurial, the [[https://bitbucket.org/fhs/hgstyle/overview][hgstyle plugin]] +If you use Mercurial, the [hgstyle plugin](https://bitbucket.org/fhs/hgstyle/overview) provides a gofmt pre-commit hook. -* Mechanical source transformation +## Mechanical source transformation One of the greatest virtues of machine-formatted code is that it can be transformed mechanically without generating unrelated formatting noise in the diffs. @@ -70,32 +71,32 @@ to make these kinds of changes manually. The easiest way to mechanically manipulate Go code is with gofmt's -r flag. The flag specifies a rewrite rule of the form - pattern -> replacement + pattern -> replacement where both pattern and replacement are valid Go expressions. In the pattern, single-character lowercase identifiers serve as wildcards matching arbitrary sub-expressions, and those expressions are substituted for the same identifiers in the replacement. -For example, this[[https://golang.org/cl/7038051][ recent change]] to the -Go core rewrote some uses of [[https://golang.org/pkg/bytes/#Compare][bytes.Compare]] -to use the more efficient [[https://golang.org/pkg/bytes/#Equal][bytes.Equal]]. +For example, this[ recent change](https://golang.org/cl/7038051) to the +Go core rewrote some uses of [bytes.Compare](https://golang.org/pkg/bytes/#Compare) +to use the more efficient [bytes.Equal](https://golang.org/pkg/bytes/#Equal). The contributor made the change using just two gofmt invocations: - gofmt -r 'bytes.Compare(a, b) == 0 -> bytes.Equal(a, b)' - gofmt -r 'bytes.Compare(a, b) != 0 -> !bytes.Equal(a, b)' + gofmt -r 'bytes.Compare(a, b) == 0 -> bytes.Equal(a, b)' + gofmt -r 'bytes.Compare(a, b) != 0 -> !bytes.Equal(a, b)' -Gofmt also enables [[https://golang.org/cmd/fix/][gofix]], +Gofmt also enables [gofix](https://golang.org/cmd/fix/), which can make arbitrarily complex source transformations. Gofix was an invaluable tool during the early days when we regularly made breaking changes to the language and libraries. For example, before Go 1 the built-in error interface didn't exist and the convention was to use the os.Error type. -When we [[https://golang.org/doc/go1.html#errors][introduced error]], +When we [introduced error](https://golang.org/doc/go1.html#errors), we provided a gofix module that rewrote all references to os.Error and its -associated helper functions to use error and the new [[https://golang.org/pkg/errors/][errors package]]. +associated helper functions to use error and the new [errors package](https://golang.org/pkg/errors/). It would have been daunting to attempt by hand, but with the code in a standard format it was relatively easy to prepare, execute, and review this change which touched almost all Go code in existence. -For more about gofix, see [[https://blog.golang.org/introducing-gofix][this article]]. +For more about gofix, see [this article](https://blog.golang.org/introducing-gofix). |