CBOR::Free::Decoder(3p)

NAME
CBOR::Free::Decoder

SYNOPSIS
    my $decoder = CBOR::Free::Decoder->new()->set_tag_handlers(
        2 => sub { DateTime->from_epoch( epoch => shift() ) },
    );

    # Enable shared/circular references:
    $decoder->preserve_references();

DESCRIPTION
This class provides an object-oriented interface to CBOR::Free’s decoder. This interface allows interpretation of tagged values.

METHODS

  $obj = CLASS->new()
Creates a new CBOR decoder object.

  $data = OBJ->decode( $CBOR )
Same as CBOR::Free’s static function of the same name but applies any tag handlers configured in set_tag_handlers().

As in CBOR::Free, any unrecognized tags prompt a warning but are otherwise ignored.

  $enabled_yn = OBJ->preserve_references( [$ENABLE] )
Enables/disables recognition of CBOR’s shared references. (If no argument is given, shared references will be enabled.)

HANDLE WITH CARE. This option can cause CBOR::Free to create circular references, which can cause memory leaks if not handled properly.

  $enabled_yn = OBJ->naive_utf8( [$ENABLE] )
Same interface as preserve_references(), but this option tells OBJ to forgo UTF-8 validation of CBOR text strings when enabled. This speeds up decoding of text strings but may confuse Perl if invalid UTF-8 is given in a CBOR text string. That may or may not break your application.

This should be safe in contexts—such as IPC—where you control the CBOR serialization and can thus ensure validity of the encoded text.

If in doubt, leave this off.

  $obj = OBJ->string_decode_cbor();
This causes OBJ to decode strings according to their CBOR type: text strings are UTF8-decoded; binary strings are left as-is. This is the default configuration, à la CBOR::Free::decode().

  $obj = OBJ->string_decode_never();
This causes OBJ to leave all strings undecoded. This is useful for applications that treat all strings as octet sequences. Note that CBOR text strings will still be validated as UTF-8 unless naive_utf8() is enabled.

  $obj = OBJ->string_decode_always();
This causes OBJ to decode all CBOR strings (including binary strings) as UTF-8, applying appropriate pre-validation unless naive_utf8() is enabled. This is useful if you expect all strings (including binary) to be UTF-8 and want to handle them in Perl as character strings instead of byte strings.

  OBJ->set_tag_handlers( %TAG_CALLBACK )
Takes a list of key/value pairs where each key is a tag (i.e., number) and each value is a coderef that CBOR::Free will run when that tag is seen during a decode operation. The coderef will receive the tagged value, and its (scalar) return will be inserted into the decoded data structure.

To unset a tag handler, assign undef to it.

This returns the OBJ.

NOTE: Handlers assigned here will only fire if CBOR::Free itself doesn’t decode the tag. For example, a handler for the “indirection” tag here will be ignored.