good good study, day day up!

vendor/gopl.io/ch5/defer1/defer.go

@@ -0,0 +1,48 @@
+// Copyright © 2016 Alan A. A. Donovan & Brian W. Kernighan.
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+
+// See page 150.
+
+// Defer1 demonstrates a deferred call being invoked during a panic.
+package main
+
+import "fmt"
+
+//!+f
+func main() {
+	f(3)
+}
+
+func f(x int) {
+	fmt.Printf("f(%d)\n", x+0/x) // panics if x == 0
+	defer fmt.Printf("defer %d\n", x)
+	f(x - 1)
+}
+
+//!-f
+
+/*
+//!+stdout
+f(3)
+f(2)
+f(1)
+defer 1
+defer 2
+defer 3
+//!-stdout
+
+//!+stderr
+panic: runtime error: integer divide by zero
+main.f(0)
+        src/gopl.io/ch5/defer1/defer.go:14
+main.f(1)
+        src/gopl.io/ch5/defer1/defer.go:16
+main.f(2)
+        src/gopl.io/ch5/defer1/defer.go:16
+
+main.f(3)
+        src/gopl.io/ch5/defer1/defer.go:16
+main.main()
+        src/gopl.io/ch5/defer1/defer.go:10
+//!-stderr
+*/