deploy: 9e1a09eec0

features/binary_formats/cbor.md

@@ -174,7 +174,20 @@ The library maps CBOR types to JSON value types as follows:
 
 !!! warning "Object keys"
 
-    CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected.
+    CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps
+    with keys other than text strings (major type 3) are rejected with a
+    [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with `allow_exceptions` set
+    to `false`, a discarded value) naming the type of the key that was found, for instance:
+
+    ```
+    [json.exception.parse_error.113] parse error at byte 2: syntax error while parsing CBOR object key: only string keys are supported, but found an unsigned integer; last byte: 0x01
+    ```
+
+    This applies to the [SAX interface](../parsing/sax_interface.md) as well, as the key is read before it is passed
+    on. This is a deliberate restriction of the library's JSON value model, not an oversight: formats built on CBOR
+    maps with integer keys, such as COSE ([RFC 9052](https://www.rfc-editor.org/rfc/rfc9052.html)) or CWT
+    ([RFC 8392](https://www.rfc-editor.org/rfc/rfc8392.html)), cannot be read with this library and need a
+    general-purpose CBOR library instead.
 
 !!! warning "UTF-8 validation of text strings"
 

features/binary_formats/cbor/index.md

@@ -185,7 +185,13 @@ CBOR negative integers (major type 1) are decoded as `-1 - n`. If the encoded ma
 
 Object keys
 
-CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than UTF-8 strings are rejected.
+CBOR allows map keys of any type, whereas JSON only allows strings as keys in object values. Therefore, CBOR maps with keys other than text strings (major type 3) are rejected with a [`parse_error.113`](https://json.nlohmann.me/home/exceptions/#jsonexceptionparse_error113) exception (or, with `allow_exceptions` set to `false`, a discarded value) naming the type of the key that was found, for instance:
+
+```
+[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing CBOR object key: only string keys are supported, but found an unsigned integer; last byte: 0x01
+```
+
+This applies to the [SAX interface](https://json.nlohmann.me/features/parsing/sax_interface/index.md) as well, as the key is read before it is passed on. This is a deliberate restriction of the library's JSON value model, not an oversight: formats built on CBOR maps with integer keys, such as COSE ([RFC 9052](https://www.rfc-editor.org/rfc/rfc9052.html)) or CWT ([RFC 8392](https://www.rfc-editor.org/rfc/rfc8392.html)), cannot be read with this library and need a general-purpose CBOR library instead.
 
 UTF-8 validation of text strings
 

features/binary_formats/messagepack.md

@@ -138,6 +138,21 @@ The library maps MessagePack types to JSON value types as follows:
 
     Any MessagePack output created by `to_msgpack` can be successfully parsed by `from_msgpack`.
 
+!!! warning "Object keys"
+
+    MessagePack allows map keys of any type, whereas JSON only allows strings as keys in object values. Like the
+    JSON-compatible [profile](https://github.com/msgpack/msgpack/blob/master/spec.md#profile) sketched in the
+    MessagePack specification, this library restricts map keys to `str` values. Maps with keys of any other type are
+    rejected with a [`parse_error.113`](../../home/exceptions.md#jsonexceptionparse_error113) exception (or, with
+    `allow_exceptions` set to `false`, a discarded value) naming the type of the key that was found, for instance:
+
+    ```
+    [json.exception.parse_error.113] parse error at byte 2: syntax error while parsing MessagePack object key: only string keys are supported, but found nil; last byte: 0xC0
+    ```
+
+    This applies to the [SAX interface](../parsing/sax_interface.md) as well, as the key is read before it is passed
+    on. Such input needs a general-purpose MessagePack library instead.
+
 !!! warning "UTF-8 validation of string values"
 
     The MessagePack specification requires `str` values (`fixstr`, `str 8`, `str 16`, `str 32`) to be valid UTF-8.

features/binary_formats/messagepack/index.md

@@ -152,6 +152,16 @@ Info
 
 Any MessagePack output created by `to_msgpack` can be successfully parsed by `from_msgpack`.
 
+Object keys
+
+MessagePack allows map keys of any type, whereas JSON only allows strings as keys in object values. Like the JSON-compatible [profile](https://github.com/msgpack/msgpack/blob/master/spec.md#profile) sketched in the MessagePack specification, this library restricts map keys to `str` values. Maps with keys of any other type are rejected with a [`parse_error.113`](https://json.nlohmann.me/home/exceptions/#jsonexceptionparse_error113) exception (or, with `allow_exceptions` set to `false`, a discarded value) naming the type of the key that was found, for instance:
+
+```
+[json.exception.parse_error.113] parse error at byte 2: syntax error while parsing MessagePack object key: only string keys are supported, but found nil; last byte: 0xC0
+```
+
+This applies to the [SAX interface](https://json.nlohmann.me/features/parsing/sax_interface/index.md) as well, as the key is read before it is passed on. Such input needs a general-purpose MessagePack library instead.
+
 UTF-8 validation of string values
 
 The MessagePack specification requires `str` values (`fixstr`, `str 8`, `str 16`, `str 32`) to be valid UTF-8. This library validates the bytes of every such string (object keys included) at decode time and rejects ill-formed UTF-8 with a [`parse_error.113`](https://json.nlohmann.me/home/exceptions/#jsonexceptionparse_error113) exception (or, with `allow_exceptions` set to `false`, a discarded value), rather than only failing later when the resulting value is dumped. `bin`/`ext`/`fixext` values are unaffected and are never validated, since they are not required to hold text.