diff options
Diffstat (limited to 'parse.go')
| -rw-r--r-- | parse.go | 36 |
1 files changed, 24 insertions, 12 deletions
@@ -19,23 +19,25 @@ var osExit = os.Exit // path represents a sequence of steps to find the output location for an // argument or subcommand in the final destination struct type path struct { - root int // index of the destination struct - fields []string // sequence of struct field names to traverse + root int // index of the destination struct + fields []reflect.StructField // sequence of struct fields to traverse } // String gets a string representation of the given path func (p path) String() string { - if len(p.fields) == 0 { - return "args" + s := "args" + for _, f := range p.fields { + s += "." + f.Name } - return "args." + strings.Join(p.fields, ".") + return s } // Child gets a new path representing a child of this path. -func (p path) Child(child string) path { +func (p path) Child(f reflect.StructField) path { // copy the entire slice of fields to avoid possible slice overwrite - subfields := make([]string, len(p.fields)+1) - copy(subfields, append(p.fields, child)) + subfields := make([]reflect.StructField, len(p.fields)+1) + copy(subfields, p.fields) + subfields[len(subfields)-1] = f return path{ root: p.root, fields: subfields, @@ -151,11 +153,20 @@ type Described interface { // walkFields calls a function for each field of a struct, recursively expanding struct fields. func walkFields(t reflect.Type, visit func(field reflect.StructField, owner reflect.Type) bool) { + walkFieldsImpl(t, visit, nil) +} + +func walkFieldsImpl(t reflect.Type, visit func(field reflect.StructField, owner reflect.Type) bool, path []int) { for i := 0; i < t.NumField(); i++ { field := t.Field(i) + field.Index = append(path, i) expand := visit(field, t) if expand && field.Type.Kind() == reflect.Struct { - walkFields(field.Type, visit) + var subpath []int + if field.Anonymous { + subpath = append(path, i) + } + walkFieldsImpl(field.Type, visit, subpath) } } } @@ -257,7 +268,7 @@ func cmdFromStruct(name string, dest path, t reflect.Type) (*command, error) { } // duplicate the entire path to avoid slice overwrites - subdest := dest.Child(field.Name) + subdest := dest.Child(field) spec := spec{ dest: subdest, long: strings.ToLower(field.Name), @@ -666,14 +677,15 @@ func (p *Parser) val(dest path) reflect.Value { v = v.Elem() } - v = v.FieldByName(field) - if !v.IsValid() { + next := v.FieldByIndex(field.Index) + if !next.IsValid() { // it is appropriate to panic here because this can only happen due to // an internal bug in this library (since we construct the path ourselves // by reflecting on the same struct) panic(fmt.Errorf("error resolving path %v: %v has no field named %v", dest.fields, v.Type(), field)) } + v = next } return v } |