Added the "dataname" tag

1 files changed, 36 insertions, 0 deletions

diff --git a/example_test.go b/example_test.go
index f71fbeb..3f7f2ab 100644
--- a/example_test.go
+++ b/example_test.go
@@ -135,6 +135,42 @@ func Example_helpText() {
 	//   --help, -h             display this help and exit
 }
 
+// This example shows the usage string generated by go-arg with custom datanames
+func Example_helpDataname() {
+	// These are the args you would pass in on the command line
+	os.Args = split("./example --help")
+
+	var args struct {
+		Input    string   `arg:"positional,dataname:DATAFILE"`
+		Output   []string `arg:"positional"`
+		Verbose  bool     `arg:"-v" help:"verbosity level"`
+		Dataset  string   `help:"dataset to use"`
+		Optimize int      `arg:"-O,help:optimization level,dataname:LEVEL"`
+		MaxJobs  int      `arg:"-j,help:maximum number of simultaneous jobs,dataname:N"`
+	}
+
+	// This is only necessary when running inside golang's runnable example harness
+	osExit = func(int) {}
+
+	MustParse(&args)
+
+	// output:
+
+	// Usage: example [--verbose] [--dataset DATASET] [--optimize LEVEL] [--maxjobs N] DATAFILE [OUTPUT [OUTPUT ...]]
+
+	// Positional arguments:
+	//   DATAFILE
+	//   OUTPUT
+
+	// Options:
+	//   --verbose, -v          verbosity level
+	//   --dataset DATASET      dataset to use
+	//   --optimize LEVEL, -O LEVEL
+	//                          optimization level
+	//   --maxjobs N, -j N      maximum number of simultanious jobs
+	//   --help, -h             display this help and exit
+}
+
 // This example shows the usage string generated by go-arg when using subcommands
 func Example_helpTextWithSubcommand() {
 	// These are the args you would pass in on the command line