Print the function being executed

details
---------
- it is difficult to track which fmt.Println statement is printing which output

examples/regular-expressions/regular-expressions.go

@@ -23,46 +23,46 @@ func main() {
 
 	// Many methods are available on these structs. Here's
 	// a match test like we saw earlier.
-	fmt.Println(r.MatchString("peach"))
+	fmt.Println("MatchString", r.MatchString("peach"))
 
 	// This finds the match for the regexp.
-	fmt.Println(r.FindString("peach punch"))
+	fmt.Println("FindString", r.FindString("peach punch"))
 
 	// This also finds the first match but returns the
 	// start and end indexes for the match instead of the
 	// matching text.
-	fmt.Println(r.FindStringIndex("peach punch"))
+	fmt.Println("FindStringIndex", r.FindStringIndex("peach punch"))
 
 	// The `Submatch` variants include information about
 	// both the whole-pattern matches and the submatches
 	// within those matches. For example this will return
 	// information for both `p([a-z]+)ch` and `([a-z]+)`.
-	fmt.Println(r.FindStringSubmatch("peach punch"))
+	fmt.Println("FindStringSubmatch", r.FindStringSubmatch("peach punch"))
 
 	// Similarly this will return information about the
 	// indexes of matches and submatches.
-	fmt.Println(r.FindStringSubmatchIndex("peach punch"))
+	fmt.Println("FindStringSubmatchIndex", r.FindStringSubmatchIndex("peach punch"))
 
 	// The `All` variants of these functions apply to all
 	// matches in the input, not just the first. For
 	// example to find all matches for a regexp.
-	fmt.Println(r.FindAllString("peach punch pinch", -1))
+	fmt.Println("FindAllString", r.FindAllString("peach punch pinch", -1))
 
 	// These `All` variants are available for the other
 	// functions we saw above as well.
-	fmt.Println(r.FindAllStringSubmatchIndex(
+	fmt.Println("FindAllStringSubmatchIndex", r.FindAllStringSubmatchIndex(
 		"peach punch pinch", -1))
 
 	// Providing a non-negative integer as the second
 	// argument to these functions will limit the number
 	// of matches.
-	fmt.Println(r.FindAllString("peach punch pinch", 2))
+	fmt.Println("FindAllString", r.FindAllString("peach punch pinch", 2))
 
 	// Our examples above had string arguments and used
 	// names like `MatchString`. We can also provide
 	// `[]byte` arguments and drop `String` from the
 	// function name.
-	fmt.Println(r.Match([]byte("peach")))
+	fmt.Println("Match", r.Match([]byte("peach")))
 
 	// When creating constants with regular expressions
 	// you can use the `MustCompile` variation of
@@ -73,7 +73,7 @@ func main() {
 
 	// The `regexp` package can also be used to replace
 	// subsets of strings with other values.
-	fmt.Println(r.ReplaceAllString("a peach", "<fruit>"))
+	fmt.Println("ReplaceAllString", r.ReplaceAllString("a peach", "<fruit>"))
 
 	// The `Func` variant allows you to transform matched
 	// text with a given function.