ShareDAV/vendor/github.com/alecthomas/kong/callbacks.go

77 lines
1.6 KiB
Go

package kong
import (
"fmt"
"reflect"
"strings"
)
type bindings map[reflect.Type]func() (reflect.Value, error)
func (b bindings) String() string {
out := []string{}
for k := range b {
out = append(out, k.String())
}
return "bindings{" + strings.Join(out, ", ") + "}"
}
func (b bindings) add(values ...interface{}) bindings {
for _, v := range values {
v := v
b[reflect.TypeOf(v)] = func() (reflect.Value, error) { return reflect.ValueOf(v), nil }
}
return b
}
// Clone and add values.
func (b bindings) clone() bindings {
out := make(bindings, len(b))
for k, v := range b {
out[k] = v
}
return out
}
func (b bindings) merge(other bindings) bindings {
for k, v := range other {
b[k] = v
}
return b
}
func getMethod(value reflect.Value, name string) reflect.Value {
method := value.MethodByName(name)
if !method.IsValid() {
if value.CanAddr() {
method = value.Addr().MethodByName(name)
}
}
return method
}
func callMethod(name string, v, f reflect.Value, bindings bindings) error {
in := []reflect.Value{}
t := f.Type()
if t.NumOut() != 1 || t.Out(0) != callbackReturnSignature {
return fmt.Errorf("return value of %T.%s() must be exactly \"error\"", v.Type(), name)
}
for i := 0; i < t.NumIn(); i++ {
pt := t.In(i)
if argf, ok := bindings[pt]; ok {
argv, err := argf()
if err != nil {
return err
}
in = append(in, argv)
} else {
return fmt.Errorf("couldn't find binding of type %s for parameter %d of %s.%s(), use kong.Bind(%s)", pt, i, v.Type(), name, pt)
}
}
out := f.Call(in)
if out[0].IsNil() {
return nil
}
return out[0].Interface().(error)
}