Rakefile

require 'bundler/gem_tasks'
require 'rake/testtask'
require 'json'

Rake::TestTask.new(:test) do |t|
  t.libs << 'test'
  t.test_files = FileList['test/*_test.rb']
end

task test: :docs

desc 'Generate standard library documentation.'
task :docs do |t|
  docs = {}

  Dir.chdir('lib/spitewaste/libspw') do |d|
    Dir['*.spw'].sort.each do |path|
      mod = File.basename path, '.spw'
      docs[mod] = extract_docs path
    end

    File.open('docs.json', ?w) { |f|
      f.write JSON.pretty_generate docs
    }
  end
end

def extract_docs path
  docs = {}
  buffer = ''

  File.open(path).each_line do |line|
    if line.strip.empty?
      buffer.clear
    elsif line[/^([^_]\S+):/]
      docs[$1] = parse_doc buffer.dup unless buffer.empty?
      buffer.clear
    elsif line[/^;/]
      buffer << line
    end
  end

  docs.sort.to_h
end

def strpack s
  s.bytes.zip(0..).sum { |b, e| b * 128 ** e }
end

def parse_stack s
  s.scan(/"[^"]*"|\S+/).map { |v|
    begin
      Integer v
    rescue
      if v[/R\((-?\d+),(-?\d+)\)/]
        n, d = $1.to_i, $2.to_i
        s = (n<=>0) * (d<=>0)
        (n.abs * 2**31 + d.abs) * 2 + (s == -1 ? 0 : 1)
      else
        strpack v.delete %('")
      end
    end
  }
end

StackRx = /(?<=\[)[^\]]*(?=\])/ # match [.*], but don't capture the brackets

def parse_doc doc
  # strip leading comment to margin and any implementation details (!)
  doc.gsub!(/^; */, '').gsub!(/^!.+\n/, '')

  head, specs = doc.split "\n\n"
  *desc, effect = head.split ?\n
  desc *= ?\n

  cases = []
  specs.scan(StackRx).each_slice 2 do |spec|
    cases << spec.map { parse_stack _1 }
  end if specs

  {full: doc, desc: desc, effect: effect, cases: cases}
end

task default: :test