Add 'x/' from commit 'a10a11b9d371f36b7c3510da32a1d70b74e27bd1'

git-subtree-dir: x
git-subtree-mainline: 7d05a6ee8f
git-subtree-split: a10a11b9d3

x/cmd/bllamo/flags.go

@@ -0,0 +1,59 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"reflect"
+	"strings"
+)
+
+// parseArgs parses the provided args using a flag.FlagSet that is
+// dynamically build using reflection for the provided type. The type fields
+// that have a "flag" tag are used to build the flags. The flag tag should
+// include either a ('-'). Example usage:
+//
+//	func main() {
+//		var flags struct {
+//			Modelfile string `flag:"f,path to the Modelfile"`
+//		}
+//
+//		fs := readFlags(os.Args[1:], &flags)
+//		fs.Parse(os.Args[1:])
+//	}
+func readFlags(name string, args []string, v any) *flag.FlagSet {
+	fs := flag.NewFlagSet(name, flag.ExitOnError)
+	defer fs.Parse(args)
+	if v == nil {
+		return fs
+	}
+
+	for i := 0; i < reflect.ValueOf(v).NumField(); i++ {
+		f := reflect.ValueOf(v).Field(i)
+		if !f.CanSet() {
+			continue
+		}
+
+		tag := f.Type().Field(i).Tag.Get("flag")
+		if tag == "" {
+			continue
+		}
+		var name, usage string
+		if i := strings.Index(tag, ","); i != -1 {
+			name = tag[:i]
+			usage = tag[i+1:]
+		} else {
+			name = tag
+		}
+
+		// TODO(bmizerany): add more types as needed
+		switch f.Kind() {
+		case reflect.String:
+			fs.StringVar(f.Addr().Interface().(*string), name, "", usage)
+		case reflect.Bool:
+			fs.BoolVar(f.Addr().Interface().(*bool), name, false, usage)
+		default:
+			panic(fmt.Sprintf("unsupported type %v", f.Kind()))
+		}
+	}
+	return fs
+}