Merge pull request #2 from alecthomas/master

Add ability to disable interspersed option support.

README.md

diff --git a/README.md b/README.md
index 714d202..a9506fd 100644
--- a/README.md
+++ b/README.md
@@ -40,7 +40,9 @@
 functions such as String(), BoolVar(), and Var(), and is therefore
 unaffected.
 
-Define flags using flag.String(), Bool(), Int(), etc. Example:
+Define flags using flag.String(), Bool(), Int(), etc.
+
+This declares an integer flag, -flagname, stored in the pointer ip, with type *int.
 
 ``` go
 var ip *int = flag.Int("flagname", 1234, "help message for flagname")
@@ -76,13 +78,13 @@
 they are all pointers; if you bind to variables, they're values.
 
 ``` go
-fmt.Println("ip has value ", *ip);
-fmt.Println("flagvar has value ", flagvar);
+fmt.Println("ip has value ", *ip)
+fmt.Println("flagvar has value ", flagvar)
 ```
 
 After parsing, the arguments after the flag are available as the
 slice flag.Args() or individually as flag.Arg(i).
-The arguments are indexed from 0 up to flag.NArg().
+The arguments are indexed from 0 through flag.NArg()-1.
 
 The pflag package also defines some new functions that are not in flag,
 that give one-letter shorthands for flags. You can use these by appending

export_test.go

diff --git a/export_test.go b/export_test.go
index 8ff8e29..8c74635 100644
--- a/export_test.go
+++ b/export_test.go
@@ -4,7 +4,10 @@
 
 package pflag
 
-import "os"
+import (
+	"io/ioutil"
+	"os"
+)
 
 // Additional routines compiled into the package only during testing.
 
@@ -12,7 +15,11 @@
 // After calling ResetForTesting, parse errors in flag handling will not
 // exit the program.
 func ResetForTesting(usage func()) {
-	commandLine = NewFlagSet(os.Args[0], ContinueOnError)
+	commandLine = &FlagSet{
+		name:          os.Args[0],
+		errorHandling: ContinueOnError,
+		output:        ioutil.Discard,
+	}
 	Usage = usage
 }
 

flag.go

diff --git a/flag.go b/flag.go
index 8f5e8e7..743e011 100644
--- a/flag.go
+++ b/flag.go
@@ -24,8 +24,10 @@
 	functions such as String(), BoolVar(), and Var(), and is therefore
 	unaffected.
 
-	Define flags using flag.String(), Bool(), Int(), etc. Example:
-		var ip *int = flag.Int("flagname", 1234, "help message for flagname")
+	Define flags using flag.String(), Bool(), Int(), etc.
+
+	This declares an integer flag, -flagname, stored in the pointer ip, with type *int.
+		var ip = flag.Int("flagname", 1234, "help message for flagname")
 	If you like, you can bind the flag to a variable using the Var() functions.
 		var flagvar int
 		func init() {
@@ -42,12 +44,12 @@
 
 	Flags may then be used directly. If you're using the flags themselves,
 	they are all pointers; if you bind to variables, they're values.
-		fmt.Println("ip has value ", *ip);
-		fmt.Println("flagvar has value ", flagvar);
+		fmt.Println("ip has value ", *ip)
+		fmt.Println("flagvar has value ", flagvar)
 
 	After parsing, the arguments after the flag are available as the
 	slice flag.Args() or individually as flag.Arg(i).
-	The arguments are indexed from 0 up to flag.NArg().
+	The arguments are indexed from 0 through flag.NArg()-1.
 
 	The pflag package also defines some new functions that are not in flag,
 	that give one-letter shorthands for flags. You can use these by appending
@@ -844,8 +846,9 @@
 	flag := &Flag{name, shorthand, usage, value, value.String()}
 	_, alreadythere := f.formal[name]
 	if alreadythere {
-		fmt.Fprintf(f.out(), "%s flag redefined: %s\n", f.name, name)
-		panic("flag redefinition") // Happens only if flags are declared with identical names
+		msg := fmt.Sprintf("%s flag redefined: %s", f.name, name)
+		fmt.Fprintln(f.out(), msg)
+		panic(msg) // Happens only if flags are declared with identical names
 	}
 	if f.formal == nil {
 		f.formal = make(map[string]*Flag)
@@ -881,6 +884,11 @@
 	commandLine.VarP(value, name, "", usage)
 }
 
+// Like Var, but accepts a shorthand letter that can be used after a single dash.
+func VarP(value Value, name, shorthand, usage string) {
+	commandLine.VarP(value, name, shorthand, usage)
+}
+
 // failf prints to standard error a formatted error and usage message and
 // returns the error.
 func (f *FlagSet) failf(format string, a ...interface{}) error {