From 5818c9d714f1a8abeb76ec5d75ad0e0560e8d780 Mon Sep 17 00:00:00 2001 From: Damien Neil Date: Mon, 8 Dec 2025 14:22:12 -0800 Subject: [PATCH] encoding/json/jsontext: add symbolic Kind constants Add constants for each possible Kind value (KindNull, KindTrue, etc.). Leave the values unchanged ('n', 't', etc.). Update documentation to reference the symbols. Fixes #71756 Change-Id: Ib33b2ad9ee55f6f547d9e6a1c5a7f00c8400d3d3 Reviewed-on: https://go-review.googlesource.com/c/go/+/728420 Auto-Submit: Damien Neil Reviewed-by: Joseph Tsai Reviewed-by: Dmitri Shuralyov LUCI-TryBot-Result: Go LUCI --- src/encoding/json/jsontext/decode.go | 8 +++---- src/encoding/json/jsontext/encode.go | 6 +++--- src/encoding/json/jsontext/token.go | 32 ++++++++++++++++------------ src/encoding/json/jsontext/value.go | 2 +- 4 files changed, 26 insertions(+), 22 deletions(-) diff --git a/src/encoding/json/jsontext/decode.go b/src/encoding/json/jsontext/decode.go index 511832f2ae..48d66fb1d4 100644 --- a/src/encoding/json/jsontext/decode.go +++ b/src/encoding/json/jsontext/decode.go @@ -306,7 +306,7 @@ func (d *decodeBuffer) PreviousTokenOrValue() []byte { // PeekKind retrieves the next token kind, but does not advance the read offset. // -// It returns 0 if an error occurs. Any such error is cached until +// It returns [KindInvalid] if an error occurs. Any such error is cached until // the next read call and it is the caller's responsibility to eventually // follow up a PeekKind call with a read call. func (d *Decoder) PeekKind() Kind { @@ -1154,9 +1154,9 @@ func (d *Decoder) StackDepth() int { // It must be a number between 0 and [Decoder.StackDepth], inclusive. // For each level, it reports the kind: // -// - 0 for a level of zero, -// - '{' for a level representing a JSON object, and -// - '[' for a level representing a JSON array. +// - [KindInvalid] for a level of zero, +// - [KindBeginObject] for a level representing a JSON object, and +// - [KindBeginArray] for a level representing a JSON array. // // It also reports the length of that JSON object or array. // Each name and value in a JSON object is counted separately, diff --git a/src/encoding/json/jsontext/encode.go b/src/encoding/json/jsontext/encode.go index e3b9c04ca6..20f020700b 100644 --- a/src/encoding/json/jsontext/encode.go +++ b/src/encoding/json/jsontext/encode.go @@ -946,9 +946,9 @@ func (e *Encoder) StackDepth() int { // It must be a number between 0 and [Encoder.StackDepth], inclusive. // For each level, it reports the kind: // -// - 0 for a level of zero, -// - '{' for a level representing a JSON object, and -// - '[' for a level representing a JSON array. +// - [KindInvalid] for a level of zero, +// - [KindBeginObject] for a level representing a JSON object, and +// - [KindBeginArray] for a level representing a JSON array. // // It also reports the length of that JSON object or array. // Each name and value in a JSON object is counted separately, diff --git a/src/encoding/json/jsontext/token.go b/src/encoding/json/jsontext/token.go index caf0174923..6d9ad4b499 100644 --- a/src/encoding/json/jsontext/token.go +++ b/src/encoding/json/jsontext/token.go @@ -472,29 +472,33 @@ func (t Token) Kind() Kind { } } +// A Kind represents the kind of a JSON token. +// // Kind represents each possible JSON token kind with a single byte, // which is conveniently the first byte of that kind's grammar -// with the restriction that numbers always be represented with '0': -// -// - 'n': null -// - 'f': false -// - 't': true -// - '"': string -// - '0': number -// - '{': object begin -// - '}': object end -// - '[': array begin -// - ']': array end -// -// An invalid kind is usually represented using 0, -// but may be non-zero due to invalid JSON data. +// with the restriction that numbers always be represented with '0'. type Kind byte +const ( + KindInvalid Kind = 0 // invalid kind + KindNull Kind = 'n' // null + KindFalse Kind = 'f' // false + KindTrue Kind = 't' // true + KindString Kind = '"' // string + KindNumber Kind = '0' // number + KindBeginObject Kind = '{' // begin object + KindEndObject Kind = '}' // end object + KindBeginArray Kind = '[' // begin array + KindEndArray Kind = ']' // end array +) + const invalidKind Kind = 0 // String prints the kind in a humanly readable fashion. func (k Kind) String() string { switch k { + case 0: + return "invalid" case 'n': return "null" case 'f': diff --git a/src/encoding/json/jsontext/value.go b/src/encoding/json/jsontext/value.go index a4b06b2a94..84c919b9dc 100644 --- a/src/encoding/json/jsontext/value.go +++ b/src/encoding/json/jsontext/value.go @@ -236,7 +236,7 @@ func (v *Value) UnmarshalJSON(b []byte) error { } // Kind returns the starting token kind. -// For a valid value, this will never include '}' or ']'. +// For a valid value, this will never include [KindEndObject] or [KindEndArray]. func (v Value) Kind() Kind { if v := v[jsonwire.ConsumeWhitespace(v):]; len(v) > 0 { return Kind(v[0]).normalize()