class FFI::Generator

@see FFI::Generator::Task for easy integration in a Rakefile
end
:total_in, :ulong, 16
:avail_in, :uint, 8,
layout :next_in, :pointer, 0,
class ZStream < FFI::Struct
ZLIB_VERNUM = 4784
module Zlib
Generates the file zlib.rb with constant values and offsets:
FFI::Generator.new “zlib.rb.ffi”, “zlib.rb”
require “ffi/tools/generator”
Translate the file:
end
end
@@@
end
s.field :total_in, :ulong
s.field :avail_in, :uint
s.field :next_in, :pointer
s.include “zlib.h”
s.name “struct z_stream_s”
struct do |s|
class ZStream < FFI::Struct
@@@
end
c.const :ZLIB_VERNUM
c.include “zlib.h”
constants do |c|
@@@
module Zlib
In file zlib.rb.ffi:
== A simple example
Generate files with C structs for FFI::Struct and C constants.
#

def constants(options = {}, &block) 

def constants(options = {}, &block)
  @constants << FFI::ConstGenerator.new(@name, @options.merge(options), &block)
end

def initialize(ffi_name, rb_name, options = {}) 

def initialize(ffi_name, rb_name, options = {})
  @ffi_name = ffi_name
  @rb_name = rb_name
  @options = options
  @name = File.basename rb_name, '.rb'
  file = File.read @ffi_name
  new_file = file.gsub(/^( *)@@@(.*?)@@@/m) do
    @constants = []
    @structs = []
    indent = $1
    original_lines = $2.count "\n"
    instance_eval $2, @ffi_name, $`.count("\n")
    new_lines = []
    @constants.each { |c| new_lines << c.to_ruby }
    @structs.each { |s| new_lines << s.generate_layout }
    new_lines = new_lines.join("\n").split "\n" # expand multiline blocks
    new_lines = new_lines.map { |line| indent + line }
    padding = original_lines - new_lines.length
    new_lines += [nil] * padding if padding >= 0
    new_lines.join "\n"
  end
  open @rb_name, 'w' do |f|
    f.puts "# This file is generated from `#{@ffi_name}'. Do not edit."
    f.puts
    f.puts new_file
  end
end

def struct(options = {}, &block) 

def struct(options = {}, &block)
  @structs << FFI::StructGenerator.new(@name, @options.merge(options), &block)
end

def to_s 

def to_s
  proc { |obj| obj.to_s.inspect }
end