BSON

BSON.jl is a Julia package for working with the Binary JSON serialisation format. It can be used as a general store for Julia data structures, with the following features:

• Lightweight and ubiquitous, with a simple JSON-like data model and clients in many languages.
• Efficient for binary data (eg. arrays of floats).
• Flexible enough to handle anything you throw at it – closures, custom types, circular data structures, etc.
• Backwards compatible, so that if data layout changes old files will still load.

julia> using BSON

julia> bson("test.bson", Dict(:a => [1+2im, 3+4im], :b => "Hello, World!"))

julia> BSON.load("test.bson")
Dict{Symbol,Any} with 2 entries:
  :a => Complex{Int64}[1+2im, 3+4im]
  :b => "Hello, World!"

(Note that the top-level object in BSON is always a Dict{Symbol,Any}).

There a few utility methods for working with BSON files.

julia> using BSON

julia> bson("test.bson", a = 1, b = 2)

julia> BSON.load("test.bson")
Dict{Symbol,Any} with 2 entries:
  :a => 1
  :b => 2

julia> using BSON: @save, @load

julia> a, b = 1, 2
(1, 2)

julia> @save "test.bson" a b # Same as above

julia> @load "test.bson" a b # Loads `a` and `b` back into the workspace

For external files you can use BSON.parse to load raw BSON data structures without any Julia-specific interpretation. In basic cases, this will look that same, but Julia-specific types will be stored in a more complex format.

julia> BSON.parse("test.bson")
Dict{Symbol,Any} with 2 entries:
  :a => 1
  :b => 2

julia> BSON.parse("test.bson")[:data]
Dict{Symbol,Any} with 4 entries:
  :tag  => "array"
  :type => Dict(:tag=>"datatype",:params=>Any[],:name=>["Core","Int64"])
  :size => [3]
  :data => UInt8[0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00  …  ]

This is also how the data will appear to readers in other languages, should you wish to move data outside of Julia.