/ 
Data-Smile-0.001000
/ Data::Smile

NAME

Data::Smile - encoder/decoder for Smile data

SYNOPSIS

use Data::Smile qw( encode_smile decode_smile dump_smile load_smile );

my $bytes = encode_smile( { hello => 'world' } );
my $data  = decode_smile( $bytes );

dump_smile( 'example.smile', { answer => 42 } );
my $round_trip = load_smile( 'example.smile' );

DESCRIPTION

This module is a wrapper for Data::Smile::PP and Data::Smile::XS. It exports four optional functions:

  • encode_smile

  • decode_smile

  • dump_smile

  • load_smile

All option arguments are optional hashrefs. Passing any other kind of reference for options throws an exception.

FUNCTIONS

encode_smile( $data, \%options )

Encodes a Perl data structure into Smile bytes and returns a byte string.

Recognised options:

  • write_header (boolean, default true)

    Include the module's Smile transport header before the payload.

  • shared_names (boolean, default true)

    Enable the shared-name marker flag when repeated object/hash key names are observed.

  • shared_values (boolean, default true)

    Enable the shared short-string-value marker flag when repeated short, non-UTF-8 scalar values are observed.

  • canonical (boolean, default false)

    If true, encode hashes/objects with keys sorted lexically.

    This is slower, but should (in theory) result in byte-identical output every time, given the same input.

Unknown option keys throw an exception.

decode_smile( $bytes, \%options )

Decodes Smile bytes into Perl data and returns the resulting structure.

Recognised options:

  • use_bigint (boolean, default true)

    For Smile big-integer and big-decimal values, return big-number objects (Math::BigInt/Math::BigFloat) instead of native numeric scalars.

  • require_header (boolean, default false)

    Require the Smile header to be present. If true and no header is found, decoding throws an exception.

  • json_bool (boolean, default true)

    If true, decode booleans as JSON::PP booleans (JSON::PP::true and JSON::PP::false) when available. If false, decode booleans as native Perl booleans.

Unknown option keys throw an exception.

dump_smile( $file, $data, \%options )

Encodes $data using encode_smile and writes the bytes to $file. Returns true on success and false on write/close failure.

$file may be:

  • a filename string

  • an open writable filehandle

  • a Path::Tiny object

  • a Path::Class::File object

The \%options hashref is passed through to encode_smile, so it accepts the same options and defaults: write_header, shared_names, shared_values, and canonical.

load_smile( $file, \%options )

Reads Smile bytes from $file, decodes them with decode_smile, and returns the resulting data structure.

$file may be:

  • a filename string

  • an open readable filehandle

  • a Path::Tiny object

  • a Path::Class::File object

The \%options hashref is passed through to decode_smile, so it accepts the same options and defaults: use_bigint, require_header, and json_bool.

PERL AND XS IMPLEMENTATIONS

Data::Smile will attempt to load and use Data::Smile::XS to encode and decode Smile data. If that module is not loadable, then it will fall back to a pure Perl implementation in Data::Smile::PP.

There is currently no environment variable or other option that can be used to manually select an implementation, but loading and using those modules directly is supported.

Both modules are believed to fully implement version 1.0.7 of the Smile specification.

COMPARISON WITH JSON

Smile is a binary data format which allows you to encode and decode JSON-like data structures. That is, collections of key-value pairs (hashes in Perl terminology, objects in JSON terminology), arrays, strings, numbers, booleans, and null (undef in Perl terminology).

Depending on the complexity of the input data, Data::Smile may produce output half the size (in bytes) or even less than comparable JSON data.

Data::Smile::XS runs at about 25% the speed of JSON::XS when encoding, and roughly the same speed when decoding.

Data::Smile::PP runs at roughly the same speed as JSON::PP when encoding, and almost three times faster when decoding.

Of course, raw encoding/decoding of JSON-like data is probably only a small part of what your application will do. If it also needs to POST the data over HTTPS or write it to a database over a TCP socket, then the speed gains of having much smaller payloads can start to add up.

BLESSED OBJECTS

Like JSON::PP and JSON::XS, Data::Smile will call the TO_JSON method on any blessed objects it gets passed. If you pass it a blessed object without a TO_JSON method, then the behaviour is currently unspecified, and the behaviour may differ between the PP and XS versions.

THE SMILE HEADER

The encode_smile option allows you to save four whole bytes by omiting the usual Smile header. The Smile header consists of ":)\n" followed by a single byte advertising which Smile features are used in the file.

The decode_smile function supports all official Smile features, so doesn't need the header and can happily parse headless Smile data.

Most decoders require the header to be present, including go-smile (Go), libsmile (C), PySmile (Python), smile-js (Javascript), and serde_smile (Rust). For this reason encode_smile will include the header in its output by default.

If you are encoding mostly very small pieces of data, and storing them somewhere you know is always going to be Smile data (like a particular column in a database which is dedicated to storing Smile data), and you know that only Data::Smile will ever be used to parse the data, then it may be safe to store Smile without the header. Otherwise, it's only four bytes, so you should probably just include it.

BUGS

Please report any bugs to https://github.com/tobyink/p5-data-smile/issues.

SEE ALSO

Data::Smile::PP, Data::Smile::XS, https://github.com/FasterXML/smile-format-specification/blob/master/smile-specification.md (Smile format specification), https://en.wikipedia.org/wiki/Smile_(data_interchange_format).

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2026 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.