edn_turbo 0.8.0

Fast Ragel-based EDN parser for Ruby.

edn_turbo can be used as a parser plugin for edn-ruby. With a few exceptions edn_turbo provides the same functionality as the edn gem, but since the edn_turbo parser is implemented in C++, it is an order of magnitude faster.

Some quick sample runs comparing time output of file reads using edn and edn_turbo (see issue 12):

irb(main):001:0> require 'benchmark'
=> true
irb(main):002:0> require 'edn'
=> true
irb(main):003:0> s = "[{\"x\" {\"id\" \"/model/952\", \"model_name\" \"person\", \"ancestors\" [\"record\" \"asset\"], \"format\" \"edn\"}, \"id\" 952, \"name\" nil, \"model_name\" \"person\", \"rel\" {}, \"description\" nil, \"age\" nil, \"updated_at\" nil, \"created_at\" nil, \"anniversary\" nil, \"job\" nil, \"start_date\" nil, \"username\" nil, \"vacation_start\" nil, \"vacation_end\" nil, \"expenses\" nil, \"rate\" nil, \"display_name\" nil, \"gross_profit_per_month\" nil}]"
=> "[{\"x\" {\"id\" \"/model/952\", \"model_name\" \"person\", \"ancestors\" [\"record\" \"asset\"], \"format\" \"edn\"}, \"id\" 952, \"name\" nil, \"model_name\" \"person\", \"rel\" {}, \"description\" nil, \"age\" nil, \"updated_at\" nil, \"created_at\" nil, \"anniversary\" nil, \"job\" nil, \"start_date\" nil, \"username\" nil, \"vacation_start\" nil, \"vacation_end\" nil, \"expenses\" nil, \"rate\" nil, \"display_name\" nil, \"gross_profit_per_month\" nil}]"
irb(main):004:0> Benchmark.realtime { 100.times { EDN::read(s) } }
=> 0.083543
irb(main):005:0> Benchmark.realtime { 100000.times { EDN::read(s) } }
=> 73.901049
irb(main):006:0> require 'edn_turbo'
=> true
irb(main):007:0> Benchmark.realtime { 100.times { EDN::read(s) } }
=> 0.007321
irb(main):008:0> Benchmark.realtime { 100000.times { EDN::read(s) } }
=> 2.866411

Dependencies

Ruby 2.6 or greater.

ruby gems:
a C++-11 capable compiler.
icu4c

Notes:

edn_turbo uses a ragel-based parser but the generated .cc file is bundled so ragel should not need to be installed.
If your system updates the installed version of icu4c, you'll likely get symbol errors when trying to use edn_turbo as the libraries it was linked against when first installed will no longer exist. To resolve this, reinstall the gem so it is built against the new icu4c libraries.

Usage

Simply require 'edn_turbo' instead of 'edn'. Otherwise (with the exceptions noted below) the API is the same as the edn gem.

    require 'edn_turbo'

    File.open(filename) do |file|
       output = EDN.read(file)
       pp output if output != EOF
    end

    # also accepts a string
    pp EDN.read("[ 1 2 3 abc ]")

    # metadata
    e = EDN.read('^String ^:foo ^{:foo false :tag Boolean :bar 2} [1 2]')
    pp e          # -> [1, 2]
    pp e.metadata # -> {:foo=>true, :tag=>#<EDN::Type::Symbol:0x007fdbea8a29b0 @symbol=:String>, :bar=>2}

Or instantiate and reuse an instance of a parser:

    require 'edn_turbo'

    p = EDN::new_parser
    File.open(filename) do |file|
       output = p.parse(file)
       pp output if output != EOF
    end

    # with a string
    pp p.parse("[ 1 2 3 abc ]")


    # set new input
    s = "(1) :abc { 1 2 }"
    p.set_input(s)

    # parse token by token
    loop do
      t = p.read
      break if t == EOF

      pp t
    end

Differences with edn gem

edn_turbo reads String and core IO types using C-api calls. However, data from StringIO sources is extracted using read() calls into the ruby side.
As of v0.6.1, edn_turbo supports EDN ratio literals, returning a ruby Rational representation for them. See https://github.com/edn-format/edn/issues/64.
As of v0.6.2, edn_turbo supports representation of ##Inf as Float::INFINITY and ##NaN as Float::NAN.
As of v0.7.1, edn_turbo requires ruby 2.5 or greater.
As of v0.7.4, edn_turbo requires ruby 2.6 or greater.
As of v0.8.0, edn_turbo replaces its edn-ruby with edn2023.