diff --git a/errors.go b/errors.go
index 8a67bbd..0b42b41 100644
--- a/errors.go
+++ b/errors.go
@@ -28,7 +28,7 @@ type SemanticError struct {
ByteOffset int64
// JSONPointer indicates that an error occurred within this JSON value
// as indicated using the JSON Pointer notation (see RFC 6901).
- JSONPointer string
+ JSONPointer jsontext.Pointer
// JSONKind is the JSON kind that could not be handled.
JSONKind jsontext.Kind // may be zero if unknown
@@ -98,7 +98,7 @@ func (e *SemanticError) Error() string {
switch {
case e.JSONPointer != "":
sb.WriteString(" within JSON value at ")
- sb.WriteString(strconv.Quote(e.JSONPointer))
+ sb.WriteString(strconv.Quote(string(e.JSONPointer)))
case e.ByteOffset > 0:
sb.WriteString(" after byte offset ")
sb.WriteString(strconv.FormatInt(e.ByteOffset, 10))
diff --git a/jsontext/coder_test.go b/jsontext/coder_test.go
index 65f2ff9..ecfe1a5 100644
--- a/jsontext/coder_test.go
+++ b/jsontext/coder_test.go
@@ -38,7 +38,7 @@ type coderTestdataEntry struct {
outIndented string // outCompacted if empty; uses " " for indent prefix and "\t" for indent
outCanonicalized string // outCompacted if empty
tokens []Token
- pointers []string
+ pointers []Pointer
}
var coderTestdata = []coderTestdataEntry{{
@@ -46,7 +46,7 @@ var coderTestdata = []coderTestdataEntry{{
in: ` null `,
outCompacted: `null`,
tokens: []Token{Null},
- pointers: []string{""},
+ pointers: []Pointer{""},
}, {
name: jsontest.Name("False"),
in: ` false `,
@@ -157,7 +157,7 @@ var coderTestdata = []coderTestdataEntry{{
Int(minInt64), Int(maxInt64), Uint(minUint64), Uint(maxUint64),
ArrayEnd,
},
- pointers: []string{
+ pointers: []Pointer{
"", "/0", "/1", "/2", "/3", "/4", "/5", "/6", "/7", "/8", "/9", "/10", "/11", "/12", "/13", "/14", "/15", "/16", "/17", "",
},
}, {
@@ -165,7 +165,7 @@ var coderTestdata = []coderTestdataEntry{{
in: ` { } `,
outCompacted: `{}`,
tokens: []Token{ObjectStart, ObjectEnd},
- pointers: []string{"", ""},
+ pointers: []Pointer{"", ""},
}, {
name: jsontest.Name("ObjectN1"),
in: ` { "0" : 0 } `,
@@ -175,7 +175,7 @@ var coderTestdata = []coderTestdataEntry{{
"0": 0
}`,
tokens: []Token{ObjectStart, String("0"), Uint(0), ObjectEnd},
- pointers: []string{"", "/0", "/0", ""},
+ pointers: []Pointer{"", "/0", "/0", ""},
}, {
name: jsontest.Name("ObjectN2"),
in: ` { "0" : 0 , "1" : 1 } `,
@@ -186,7 +186,7 @@ var coderTestdata = []coderTestdataEntry{{
"1": 1
}`,
tokens: []Token{ObjectStart, String("0"), Uint(0), String("1"), Uint(1), ObjectEnd},
- pointers: []string{"", "/0", "/0", "/1", "/1", ""},
+ pointers: []Pointer{"", "/0", "/0", "/1", "/1", ""},
}, {
name: jsontest.Name("ObjectNested"),
in: ` { "0" : { "1" : { "2" : { "3" : { "4" : { } } } } } } `,
@@ -204,7 +204,7 @@ var coderTestdata = []coderTestdataEntry{{
}
}`,
tokens: []Token{ObjectStart, String("0"), ObjectStart, String("1"), ObjectStart, String("2"), ObjectStart, String("3"), ObjectStart, String("4"), ObjectStart, ObjectEnd, ObjectEnd, ObjectEnd, ObjectEnd, ObjectEnd, ObjectEnd},
- pointers: []string{
+ pointers: []Pointer{
"",
"/0", "/0",
"/0/1", "/0/1",
@@ -268,7 +268,7 @@ var coderTestdata = []coderTestdataEntry{{
ObjectEnd,
ObjectEnd,
},
- pointers: []string{
+ pointers: []Pointer{
"",
"/", "/",
"//44444", "//44444",
@@ -289,7 +289,7 @@ var coderTestdata = []coderTestdataEntry{{
in: ` [ ] `,
outCompacted: `[]`,
tokens: []Token{ArrayStart, ArrayEnd},
- pointers: []string{"", ""},
+ pointers: []Pointer{"", ""},
}, {
name: jsontest.Name("ArrayN1"),
in: ` [ 0 ] `,
@@ -298,7 +298,7 @@ var coderTestdata = []coderTestdataEntry{{
0
]`,
tokens: []Token{ArrayStart, Uint(0), ArrayEnd},
- pointers: []string{"", "/0", ""},
+ pointers: []Pointer{"", "/0", ""},
}, {
name: jsontest.Name("ArrayN2"),
in: ` [ 0 , 1 ] `,
@@ -322,7 +322,7 @@ var coderTestdata = []coderTestdataEntry{{
]
]`,
tokens: []Token{ArrayStart, ArrayStart, ArrayStart, ArrayStart, ArrayStart, ArrayEnd, ArrayEnd, ArrayEnd, ArrayEnd, ArrayEnd},
- pointers: []string{
+ pointers: []Pointer{
"",
"/0",
"/0/0",
@@ -388,7 +388,7 @@ var coderTestdata = []coderTestdataEntry{{
String("objectN2"), ObjectStart, String("0"), Uint(0), String("1"), Uint(1), ObjectEnd,
ObjectEnd,
},
- pointers: []string{
+ pointers: []Pointer{
"",
"/literals", "/literals",
"/literals/0",
@@ -494,8 +494,8 @@ func testCoderInterleaved(t *testing.T, where jsontest.CasePos, modeName string,
func TestCoderStackPointer(t *testing.T) {
tests := []struct {
token Token
- wantWithRejectDuplicateNames string
- wantWithAllowDuplicateNames string
+ wantWithRejectDuplicateNames Pointer
+ wantWithAllowDuplicateNames Pointer
}{
{Null, "", ""},
@@ -549,14 +549,14 @@ func TestCoderStackPointer(t *testing.T) {
for _, allowDupes := range []bool{false, true} {
var name string
- var want func(i int) string
+ var want func(i int) Pointer
switch allowDupes {
case false:
name = "RejectDuplicateNames"
- want = func(i int) string { return tests[i].wantWithRejectDuplicateNames }
+ want = func(i int) Pointer { return tests[i].wantWithRejectDuplicateNames }
case true:
name = "AllowDuplicateNames"
- want = func(i int) string { return tests[i].wantWithAllowDuplicateNames }
+ want = func(i int) Pointer { return tests[i].wantWithAllowDuplicateNames }
}
t.Run(name, func(t *testing.T) {
diff --git a/jsontext/decode.go b/jsontext/decode.go
index d1ef6ae..e12a37b 100644
--- a/jsontext/decode.go
+++ b/jsontext/decode.go
@@ -1052,7 +1052,7 @@ func (d *Decoder) StackIndex(i int) (Kind, int64) {
// StackPointer returns a JSON Pointer (RFC 6901) to the most recently read value.
// Object names are only present if [AllowDuplicateNames] is false, otherwise
// object members are represented using their index within the object.
-func (d *Decoder) StackPointer() string {
+func (d *Decoder) StackPointer() Pointer {
d.s.Names.copyQuotedBuffer(d.s.buf)
- return string(d.s.appendStackPointer(nil))
+ return Pointer(d.s.appendStackPointer(nil))
}
diff --git a/jsontext/decode_test.go b/jsontext/decode_test.go
index fc156ed..11b25b4 100644
--- a/jsontext/decode_test.go
+++ b/jsontext/decode_test.go
@@ -48,7 +48,7 @@ func testDecoder(t *testing.T, where jsontest.CasePos, typeName string, td coder
switch typeName {
case "Token":
var tokens []Token
- var pointers []string
+ var pointers []Pointer
for {
tok, err := dec.ReadToken()
if err != nil {
@@ -176,7 +176,7 @@ type decoderMethodCall struct {
wantKind Kind
wantOut tokOrVal
wantErr error
- wantPointer string
+ wantPointer Pointer
}
var decoderErrorTestdata = []struct {
diff --git a/jsontext/encode.go b/jsontext/encode.go
index e5f3965..1035aa9 100644
--- a/jsontext/encode.go
+++ b/jsontext/encode.go
@@ -917,7 +917,7 @@ func (e *Encoder) StackIndex(i int) (Kind, int64) {
// StackPointer returns a JSON Pointer (RFC 6901) to the most recently written value.
// Object names are only present if [AllowDuplicateNames] is false, otherwise
// object members are represented using their index within the object.
-func (e *Encoder) StackPointer() string {
+func (e *Encoder) StackPointer() Pointer {
e.s.Names.copyQuotedBuffer(e.s.Buf)
- return string(e.s.appendStackPointer(nil))
+ return Pointer(e.s.appendStackPointer(nil))
}
diff --git a/jsontext/encode_test.go b/jsontext/encode_test.go
index 376176a..b7a53c7 100644
--- a/jsontext/encode_test.go
+++ b/jsontext/encode_test.go
@@ -48,7 +48,7 @@ func testEncoder(t *testing.T, where jsontest.CasePos, formatName, typeName stri
switch typeName {
case "Token":
- var pointers []string
+ var pointers []Pointer
for _, tok := range td.tokens {
if err := enc.WriteToken(tok); err != nil {
t.Fatalf("%s: Encoder.WriteToken error: %v", where, err)
@@ -136,7 +136,7 @@ func testFaultyEncoder(t *testing.T, where jsontest.CasePos, typeName string, td
type encoderMethodCall struct {
in tokOrVal
wantErr error
- wantPointer string
+ wantPointer Pointer
}
var encoderErrorTestdata = []struct {
diff --git a/jsontext/example_test.go b/jsontext/example_test.go
index c694b4c..3ab3e2d 100644
--- a/jsontext/example_test.go
+++ b/jsontext/example_test.go
@@ -34,7 +34,7 @@ func Example_stringReplace() {
// Using a Decoder and Encoder, we can parse through every token,
// check and modify the token if necessary, and
// write the token to the output.
- var replacements []string
+ var replacements []jsontext.Pointer
in := strings.NewReader(input)
dec := jsontext.NewDecoder(in)
out := new(bytes.Buffer)
diff --git a/jsontext/pointer.go b/jsontext/pointer.go
new file mode 100644
index 0000000..90f566f
--- /dev/null
+++ b/jsontext/pointer.go
@@ -0,0 +1,23 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build goexperiment.rangefunc
+
+package jsontext
+
+import "iter"
+
+// Tokens returns an iterator over the reference tokens in the JSON pointer,
+// starting from the first token until the last token (unless stopped early).
+// A token is either a JSON object name or an index to a JSON array element
+// encoded as a base-10 integer value.
+func (p Pointer) Tokens() iter.Seq[string] {
+ return func(yield func(string) bool) {
+ for len(p) > 0 {
+ if !yield(p.nextToken()) {
+ return
+ }
+ }
+ }
+}
diff --git a/jsontext/pointer_test.go b/jsontext/pointer_test.go
new file mode 100644
index 0000000..bd94370
--- /dev/null
+++ b/jsontext/pointer_test.go
@@ -0,0 +1,42 @@
+// Copyright 2024 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build goexperiment.rangefunc
+
+package jsontext
+
+import (
+ "iter"
+ "slices"
+ "testing"
+)
+
+func TestPointerTokens(t *testing.T) {
+ // TODO(https://go.dev/issue/61899): Use slices.Collect.
+ collect := func(seq iter.Seq[string]) (x []string) {
+ for v := range seq {
+ x = append(x, v)
+ }
+ return x
+ }
+
+ tests := []struct {
+ in Pointer
+ want []string
+ }{
+ {in: "", want: nil},
+ {in: "a", want: []string{"a"}},
+ {in: "~", want: []string{"~"}},
+ {in: "/a", want: []string{"a"}},
+ {in: "/foo/bar", want: []string{"foo", "bar"}},
+ {in: "///", want: []string{"", "", ""}},
+ {in: "/~0~1", want: []string{"~/"}},
+ }
+ for _, tt := range tests {
+ got := collect(tt.in.Tokens())
+ if !slices.Equal(got, tt.want) {
+ t.Errorf("Pointer(%q).Tokens = %q, want %q", tt.in, got, tt.want)
+ }
+ }
+}
diff --git a/jsontext/state.go b/jsontext/state.go
index 5c1a55d..1a15937 100644
--- a/jsontext/state.go
+++ b/jsontext/state.go
@@ -7,6 +7,7 @@ package jsontext
import (
"math"
"strconv"
+ "strings"
"github.com/go-json-experiment/json/internal/jsonwire"
)
@@ -48,6 +49,24 @@ func (s *state) reset() {
s.Namespaces.reset()
}
+// Pointer is a JSON Pointer (RFC 6901) that references a particular JSON value
+// relative to the root of the top-level JSON value.
+type Pointer string
+
+// nextToken returns the next token in the pointer, reducing the length of p.
+func (p *Pointer) nextToken() (token string) {
+ *p = Pointer(strings.TrimPrefix(string(*p), "/"))
+ i := min(uint(strings.IndexByte(string(*p), '/')), uint(len(*p)))
+ token = string(*p)[:i]
+ *p = (*p)[i:]
+ if strings.Contains(token, "~") {
+ // Per RFC 6901, section 3, unescape '~' and '/' characters.
+ token = strings.ReplaceAll(token, "~1", "/")
+ token = strings.ReplaceAll(token, "~0", "~")
+ }
+ return token
+}
+
// appendStackPointer appends a JSON Pointer (RFC 6901) to the current value.
// The returned pointer is only accurate if s.names is populated,
// otherwise it uses the numeric index as the object member name.