New APIs (all backward-compatible)

Iteration with error/break control

• ArrayEachErr — like ArrayEach but the callback returns error. Return io.EOF for graceful stop, any other error to abort. Resolves #53, #129, #176, #230, #255, #262.
• EachKeyErr — same pattern for EachKey.

Safe string handling

• Escape(s string) []byte — RFC 8259 string escaping (inverse of Unescape). Produces a quoted JSON string literal.
• SetString(data, val, keys...) — Set with auto-quoted value. No more invalid JSON from forgetting quotes. Resolves #144, #158, #218, #270.

Container accessors

• GetArrayLen(data, keys...) (int, error) — count array elements without a callback. Resolves #175, #261.
• GetObjectLen(data, keys...) (int, error) — count object key-value pairs.
• GetUint64(data, keys...) (uint64, error) — uint64 variant of GetInt. Resolves #271.

Delete found signal

• DeleteFound(data, keys...) ([]byte, bool) — returns whether the key was found. Resolves #229.

Wildcard paths

• EachKeyWildcard, ArrayEachWildcard, SetWildcard — [*] path component to iterate/set all elements. Resolves #112.

  jsonparser.SetWildcard(data, []byte("true"), "users", "[*]", "active")

JSONPath compiled paths

• ParsePath("$.users[0].name") → []string{"users", "[0]", "name"}
• CompilePath + CompiledPath — pre-compile and reuse with Get/Set/Delete/etc. Resolves #234, #251.

  path, _ := jsonparser.CompilePath("$.person.name.fullName")
  name, _ := path.Get(data)  // reuse across calls

Fixes

• EachKey no longer panics with >64 key components (#56)
• Set pre-allocates output buffer, reducing allocations from 6 to 1 (#107)

Proof coverage

• 3 new SYS-REQs (112: container length, 113: wildcard paths, 114: compiled paths)
• 121 total requirements, 0 errors, 0 warnings, 384 MC/DC witness rows (0 uncovered)
• All new APIs traced via source-native annotations

Acknowledgments

Implemented by codex (gpt-5-codex) via codex exec. Proof coverage by ReqProof.

Full changelog: CHANGELOG.md