1 files changed, 107 insertions, 0 deletions
diff --git a/vendor/github.com/alexflint/go-arg/reflect.go b/vendor/github.com/alexflint/go-arg/reflect.go
new file mode 100644
index 0000000..cd80be7
--- /dev/null
+++ b/vendor/github.com/alexflint/go-arg/reflect.go
@@ -0,0 +1,107 @@
+package arg
+
+import (
+	"encoding"
+	"fmt"
+	"reflect"
+	"unicode"
+	"unicode/utf8"
+
+	scalar "github.com/alexflint/go-scalar"
+)
+
+var textUnmarshalerType = reflect.TypeOf([]encoding.TextUnmarshaler{}).Elem()
+
+// cardinality tracks how many tokens are expected for a given spec
+//  - zero is a boolean, which does to expect any value
+//  - one is an ordinary option that will be parsed from a single token
+//  - multiple is a slice or map that can accept zero or more tokens
+type cardinality int
+
+const (
+	zero cardinality = iota
+	one
+	multiple
+	unsupported
+)
+
+func (k cardinality) String() string {
+	switch k {
+	case zero:
+		return "zero"
+	case one:
+		return "one"
+	case multiple:
+		return "multiple"
+	case unsupported:
+		return "unsupported"
+	default:
+		return fmt.Sprintf("unknown(%d)", int(k))
+	}
+}
+
+// cardinalityOf returns true if the type can be parsed from a string
+func cardinalityOf(t reflect.Type) (cardinality, error) {
+	if scalar.CanParse(t) {
+		if isBoolean(t) {
+			return zero, nil
+		}
+		return one, nil
+	}
+
+	// look inside pointer types
+	if t.Kind() == reflect.Ptr {
+		t = t.Elem()
+	}
+
+	// look inside slice and map types
+	switch t.Kind() {
+	case reflect.Slice:
+		if !scalar.CanParse(t.Elem()) {
+			return unsupported, fmt.Errorf("cannot parse into %v because %v not supported", t, t.Elem())
+		}
+		return multiple, nil
+	case reflect.Map:
+		if !scalar.CanParse(t.Key()) {
+			return unsupported, fmt.Errorf("cannot parse into %v because key type %v not supported", t, t.Elem())
+		}
+		if !scalar.CanParse(t.Elem()) {
+			return unsupported, fmt.Errorf("cannot parse into %v because value type %v not supported", t, t.Elem())
+		}
+		return multiple, nil
+	default:
+		return unsupported, fmt.Errorf("cannot parse into %v", t)
+	}
+}
+
+// isBoolean returns true if the type can be parsed from a single string
+func isBoolean(t reflect.Type) bool {
+	switch {
+	case t.Implements(textUnmarshalerType):
+		return false
+	case t.Kind() == reflect.Bool:
+		return true
+	case t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Bool:
+		return true
+	default:
+		return false
+	}
+}
+
+// isExported returns true if the struct field name is exported
+func isExported(field string) bool {
+	r, _ := utf8.DecodeRuneInString(field) // returns RuneError for empty string or invalid UTF8
+	return unicode.IsLetter(r) && unicode.IsUpper(r)
+}
+
+// isZero returns true if v contains the zero value for its type
+func isZero(v reflect.Value) bool {
+	t := v.Type()
+	if t.Kind() == reflect.Slice || t.Kind() == reflect.Map {
+		return v.IsNil()
+	}
+	if !t.Comparable() {
+		return false
+	}
+	return v.Interface() == reflect.Zero(t).Interface()
+}