doc panic

src/26-panic.go

@@ -1,8 +1,21 @@
+                     // Panic
+
+                     // A `panic` means something went unexpectedly wrong.
+                     // Mostly we use it to fail fast on errors that
+                     // shouldn't occur during normal operation.
 package main
 
-import "fmt"
-
 func main() {
-	panic("O noes")
-	fmt.Println("Finished")
-}
+	panic("O noes")  // We'll use panic throught this book to check for
+}	                 // unexpected errors. This is the only program in the
+                     // book designed to panic.
+
+/*
+$ go run 26-panic.go
+panic: O noes
+
+goroutine 1 [running]:
+main.main()
+	/.../src/26-panic.go:4 +0x47
+...
+*/