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selector: simplify the public interface of the package

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Those extra interfaces are not necessary.
This commit is contained in:
Michael Muré
2024-08-31 15:48:24 +02:00
parent 5b26d85c37
commit b0c96b25dc
2 changed files with 26 additions and 54 deletions
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76
capability/policy/selector/selector.go
View File

@@ -13,7 +13,7 @@ import (
// Selector describes a UCAN policy selector, as specified here:
// https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#selectors
type Selector []Segment
type Selector []segment
func (s Selector) String() string {
var str string
@@ -23,23 +23,6 @@ func (s Selector) String() string {
return str
}
type Segment interface {
// Identity flags that this selector is the identity selector.
Identity() bool
// Optional flags that this selector is optional.
Optional() bool
// Iterator flags that this selector is an iterator segment.
Iterator() bool
// Slice flags that this segemnt targets a range of a slice.
Slice() []int
// Field is the name of a field in a struct/map.
Field() string
// Index is an index of a slice.
Index() int
// String returns the segment's string representation.
String() string
}
var Identity = segment{".", true, false, false, nil, "", 0}
var (
@@ -58,37 +41,44 @@ type segment struct {
index int
}
// String returns the segment's string representation.
func (s segment) String() string {
return s.str
}
// Identity flags that this selector is the identity selector.
func (s segment) Identity() bool {
return s.identity
}
// Optional flags that this selector is optional.
func (s segment) Optional() bool {
return s.optional
}
// Iterator flags that this selector is an iterator segment.
func (s segment) Iterator() bool {
return s.iterator
}
// Slice flags that this segment targets a range of a slice.
func (s segment) Slice() []int {
return s.slice
}
// Field is the name of a field in a struct/map.
func (s segment) Field() string {
return s.field
}
// Index is an index of a slice.
func (s segment) Index() int {
return s.index
}
func Parse(str string) (Selector, error) {
if string(str[0]) != "." {
return nil, NewParseError("selector must start with identity segment '.'", str, 0, string(str[0]))
return nil, newParseError("selector must start with identity segment '.'", str, 0, string(str[0]))
}
col := 0
@@ -102,7 +92,7 @@ func Parse(str string) (Selector, error) {
switch seg {
case ".":
if len(sel) > 0 && sel[len(sel)-1].Identity() {
return nil, NewParseError("selector contains unsupported recursive descent segment: '..'", str, col, tok)
return nil, newParseError("selector contains unsupported recursive descent segment: '..'", str, col, tok)
}
sel = append(sel, Identity)
case "[]":
@@ -114,7 +104,7 @@ func Parse(str string) (Selector, error) {
if indexRegex.MatchString(lookup) { // index
idx, err := strconv.Atoi(lookup)
if err != nil {
return nil, NewParseError("invalid index", str, col, tok)
return nil, newParseError("invalid index", str, col, tok)
}
sel = append(sel, segment{str: tok, optional: opt, index: idx})
} else if strings.HasPrefix(lookup, "\"") && strings.HasSuffix(lookup, "\"") { // explicit field
@@ -127,25 +117,25 @@ func Parse(str string) (Selector, error) {
} else {
i, err := strconv.Atoi(splt[0])
if err != nil {
return nil, NewParseError("invalid slice index", str, col, tok)
return nil, newParseError("invalid slice index", str, col, tok)
}
rng = append(rng, i)
}
if splt[1] != "" {
i, err := strconv.Atoi(splt[1])
if err != nil {
return nil, NewParseError("invalid slice index", str, col, tok)
return nil, newParseError("invalid slice index", str, col, tok)
}
rng = append(rng, i)
}
sel = append(sel, segment{str: tok, optional: opt, slice: rng})
} else {
return nil, NewParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
}
} else if fieldRegex.MatchString(seg) {
sel = append(sel, segment{str: tok, optional: opt, field: seg[1:]})
} else {
return nil, NewParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
}
}
col += len(tok)
@@ -193,15 +183,6 @@ func tokenize(str string) []string {
return toks
}
type ParseError interface {
error
Name() string
Message() string
Source() string
Column() int
Token() string
}
type parseerr struct {
msg string
src string
@@ -233,7 +214,7 @@ func (p parseerr) Token() string {
return p.tok
}
func NewParseError(message string, source string, column int, token string) error {
func newParseError(message string, source string, column int, token string) error {
return parseerr{message, source, column, token}
}
@@ -312,7 +293,7 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
} else if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
}
} else if seg.Field() != "" {
@@ -324,7 +305,7 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("object has no field named: %s", seg.Field()), at)
return nil, nil, newResolutionError(fmt.Sprintf("object has no field named: %s", seg.Field()), at)
}
} else {
return nil, nil, err
@@ -334,17 +315,17 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
} else if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
return nil, nil, newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
}
} else if seg.Slice() != nil {
if cur != nil && cur.Kind() == datamodel.Kind_List {
return nil, nil, NewResolutionError("list slice selection not yet implemented", at)
return nil, nil, newResolutionError("list slice selection not yet implemented", at)
} else if cur != nil && cur.Kind() == datamodel.Kind_Bytes {
return nil, nil, NewResolutionError("bytes slice selection not yet implemented", at)
return nil, nil, newResolutionError("bytes slice selection not yet implemented", at)
} else if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("can not index: %s on kind: %s", seg.Field(), kindString(cur)), at)
return nil, nil, newResolutionError(fmt.Sprintf("can not index: %s on kind: %s", seg.Field(), kindString(cur)), at)
}
} else {
at = append(at, fmt.Sprintf("%d", seg.Index()))
@@ -355,7 +336,7 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
}
} else {
return nil, nil, err
@@ -365,7 +346,7 @@ func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.No
} else if seg.Optional() {
cur = nil
} else {
return nil, nil, NewResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
return nil, nil, newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
}
}
}
@@ -393,13 +374,6 @@ func isMissing(err error) bool {
return false
}
type ResolutionError interface {
error
Name() string
Message() string
At() []string
}
type resolutionerr struct {
msg string
at []string
@@ -421,6 +395,6 @@ func (r resolutionerr) Error() string {
return r.Message()
}
func NewResolutionError(message string, at []string) error {
func newResolutionError(message string, at []string) error {
return resolutionerr{message, at}
}

4
capability/policy/selector/selector_test.go
View File

@@ -377,9 +377,7 @@ func TestSelect(t *testing.T) {
fmt.Println(err)
if _, ok := err.(ResolutionError); !ok {
t.Fatalf("error was not a resolution error")
}
require.ErrorAs(t, err, &resolutionerr{}, "error was not a resolution error")
})
t.Run("optional not exists", func(t *testing.T) {