diff options
Diffstat (limited to 'doc/effective_go.html')
| -rw-r--r-- | doc/effective_go.html | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/doc/effective_go.html b/doc/effective_go.html index 3f6f89b8b..8f94f467b 100644 --- a/doc/effective_go.html +++ b/doc/effective_go.html @@ -824,7 +824,7 @@ executions. Here's a silly example. </p> <pre> -for i := 0; i < 5; i++ { +for i := 0; i < 5; i++ { defer fmt.Printf("%d ", i) } </pre> @@ -1486,7 +1486,7 @@ for a min function that chooses the least of a list of integers: func Min(a ...int) int { min := int(^uint(0) >> 1) // largest int for _, i := range a { - if i < min { + if i < min { min = i } } @@ -2670,7 +2670,7 @@ suppresses the usual check for a <code>return</code> statement. // A toy implementation of cube root using Newton's method. func CubeRoot(x float64) float64 { z := x/3 // Arbitrary intitial value - for i := 0; i < 1e6; i++ { + for i := 0; i < 1e6; i++ { prevz := z z -= (z*z*z-x) / (3*z*z) if veryClose(z, prevz) { @@ -2705,7 +2705,7 @@ func init() { <p> When <code>panic</code> is called, including implicitly for run-time -errors such indexing an array out of bounds or failing a type +errors such as indexing an array out of bounds or failing a type assertion, it immediately stops execution of the current function and begins unwinding the stack of the goroutine, running any deferred functions along the way. If that unwinding reaches the top of the @@ -2727,7 +2727,7 @@ inside a server without killing the other executing goroutines. </p> <pre> -func server(workChan <-chan *Work) { +func server(workChan <-chan *Work) { for work := range workChan { go safelyDo(work) } @@ -2751,7 +2751,16 @@ calling <code>recover</code> handles the condition completely. </p> <p> -Note that with this recovery pattern in place, the <code>do</code> +Because <code>recover</code> always returns <code>nil</code> unless called directly +from a deferred function, deferred code can call library routines that themselves +use <code>panic</code> and <code>recover</code> without failing. As an example, +the deferred function in <code>safelyDo</code> might call a logging function before +calling <code>recover</code>, and that logging code would run unaffected +by the panicking state. +</p> + +<p> +With our recovery pattern in place, the <code>do</code> function (and anything it calls) can get out of any bad situation cleanly by calling <code>panic</code>. We can use that idea to simplify error handling in complex software. Let's look at an @@ -2876,7 +2885,7 @@ func main() { } func QR(w http.ResponseWriter, req *http.Request) { - templ.Execute(req.FormValue("s"), w) + templ.Execute(w, req.FormValue("s")) } func UrlHtmlFormatter(w io.Writer, fmt string, v ...interface{}) { |