From 44361140c02556a0a71bc52299149bb8de26024b Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Fri, 29 Jan 2021 10:25:34 -0800 Subject: embed: update docs for proposal tweaks //go:embed variables can be type aliases. //go:embed variables can't be local to a function. For #43216 For #43602 Fixes #43978 Change-Id: Ib1d104dfa32b97c91d8bfc5ed5d461ca14da188f Reviewed-on: https://go-review.googlesource.com/c/go/+/288072 Trust: Ian Lance Taylor Reviewed-by: Russ Cox --- src/embed/embed.go | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/src/embed/embed.go b/src/embed/embed.go index cc6855e6a5..f12bf31e76 100644 --- a/src/embed/embed.go +++ b/src/embed/embed.go @@ -9,18 +9,28 @@ // files read from the package directory or subdirectories at compile time. // // For example, here are three ways to embed a file named hello.txt -// and then print its contents at run time: +// and then print its contents at run time. // -// import "embed" +// Embedding one file into a string: +// +// import _ "embed" // // //go:embed hello.txt // var s string // print(s) // +// Embedding one file into a slice of bytes: +// +// import _ "embed" +// // //go:embed hello.txt // var b []byte // print(string(b)) // +// Embedded one or more files into a file system: +// +// import "embed" +// // //go:embed hello.txt // var f embed.FS // data, _ := f.ReadFile("hello.txt") @@ -34,8 +44,8 @@ // The directive must immediately precede a line containing the declaration of a single variable. // Only blank lines and ‘//’ line comments are permitted between the directive and the declaration. // -// The variable must be of type string, []byte, or FS exactly. Named types or type aliases -// derived from those types are not allowed. +// The type of the variable must be a string type, or a slice of a byte type, +// or FS (or an alias of FS). // // For example: // @@ -70,8 +80,8 @@ // // The //go:embed directive can be used with both exported and unexported variables, // depending on whether the package wants to make the data available to other packages. -// Similarly, it can be used with both global and function-local variables, -// depending on what is more convenient in context. +// It can only be used with global variables at package scope, +// not with local variables. // // Patterns must not match files outside the package's module, such as ‘.git/*’ or symbolic links. // Matches for empty directories are ignored. After that, each pattern in a //go:embed line -- cgit v1.2.3-54-g00ecf