Add 'mrbgems/mruby-pack/' from commit '383a9c79'

git-subtree-dir: mrbgems/mruby-pack
git-subtree-mainline: 842e6945
git-subtree-split: 383a9c79

mrbgems/mruby-pack/.gitignore

+gem_*
+gem-*
+mrb-*.a
+src/*.o
+/tmp

mrbgems/mruby-pack/.travis.yml

+script:
+  - "ruby run_test.rb all test"

mrbgems/mruby-pack/README.md

+mruby-pack (pack / unpack)
+=========
+
+mruby-pack provides `Array#pack` and `String#unpack` for mruby.
+
+
+## Installation
+Add the line below into your `build_config.rb`:
+
+```
+  conf.gem :github => 'iij/mruby-pack'
+```
+
+There is no dependency on other mrbgems.
+
+
+## Supported template string
+ - A : arbitrary binary string (space padded, count is width)
+ - a : arbitrary binary string (null padded, count is width)
+ - C : 8-bit unsigned (unsigned char)
+ - c : 8-bit signed (signed char)
+ - D, d: 64-bit float, native format
+ - E : 64-bit float, little endian byte order
+ - e : 32-bit float, little endian byte order
+ - F, f: 32-bit float, native format
+ - G : 64-bit float, network (big-endian) byte order
+ - g : 32-bit float, network (big-endian) byte order
+ - H : hex string (high nibble first)
+ - h : hex string (low nibble first)
+ - I : unsigned integer, native endian (`unsigned int` in C)
+ - i : signed integer, native endian (`int` in C)
+ - L : 32-bit unsigned, native endian (`uint32_t`)
+ - l : 32-bit signed, native endian (`int32_t`)
+ - m : base64 encoded string (see RFC 2045, count is width)
+ - N : 32-bit unsigned, network (big-endian) byte order
+ - n : 16-bit unsigned, network (big-endian) byte order
+ - Q : 64-bit unsigned, native endian (`uint64_t`)
+ - q : 64-bit signed, native endian (`int64_t`)
+ - S : 16-bit unsigned, native endian (`uint16_t`)
+ - s : 16-bit signed, native endian (`int16_t`)
+ - U : UTF-8 character
+ - V : 32-bit unsigned, VAX (little-endian) byte order
+ - v : 16-bit unsigned, VAX (little-endian) byte order
+ - x : null byte
+ - Z : same as "a", except that null is added with *
+
+
+
+## License
+
+Copyright (c) 2012 Internet Initiative Japan Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a 
+copy of this software and associated documentation files (the "Software"), 
+to deal in the Software without restriction, including without limitation 
+the rights to use, copy, modify, merge, publish, distribute, sublicense, 
+and/or sell copies of the Software, and to permit persons to whom the 
+Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in 
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+DEALINGS IN THE SOFTWARE.
+

mrbgems/mruby-pack/mrbgem.rake

+MRuby::Gem::Specification.new('mruby-pack') do |spec|
+  spec.license = 'MIT'
+  spec.authors = 'Internet Initiative Japan Inc.'
+
+  spec.cc.include_paths << "#{build.root}/src"
+end

mrbgems/mruby-pack/packtest.rb

+# encoding: ascii
+
+# a = Array, s = String, t = Template
+
+def packtest(a, s, t)
+  begin
+    r = a.pack(t)
+    return if r == s
+    puts "#{a.inspect}.pack(#{t.inspect}) -> #{r.inspect} should be #{s.inspect}"
+  rescue => r
+    unless r.is_a? s
+      puts "#{a.inspect}.pack(#{t.inspect}) -> #{r.inspect} should be #{s.inspect}"
+    end
+  end
+end
+
+def unpacktest(a, s, t)
+  r = s.unpack(t)
+  return if r == a
+  puts "#{s.inspect}.unpack(#{t.inspect}) -> #{r.inspect} should be #{a.inspect}"
+end
+
+def pptest(a, s, t)
+  packtest(a, s, t)
+  unpacktest(a, s, t)
+end
+
+pptest [1], "\x01", "C"
+
+packtest [1.1], "\x01", "C"
+packtest [-1], "\xff", "C"
+packtest [1,2], "\x01\x02", "C2"
+#packtest [1], "X", ArgumentError
+
+unpacktest [48, nil], "0", "CC"
+unpacktest [160, -96], "\xa0\xa0", "Cc"
+unpacktest [49, 50, 51], "123", "C*"
+
+pptest [12849], "12", "S"
+unpacktest [nil], "0", "S"
+unpacktest [12849, nil], "123", "SS"
+unpacktest [12849], "123", "S*"
+
+pptest [10000], "\x27\x10", "s>"
+pptest [-10000], "\xd8\xf0", "s>"
+pptest [50000], "\xc3\x50", "S>"
+
+pptest [10000], "\x10\x27", "s<"
+pptest [-10000], "\xf0\xd8", "s<"
+pptest [50000], "\x50\xc3", "S<"
+
+pptest [1000000000], "\x3b\x9a\xca\x00", "l>"
+pptest [-1000000000], "\xc4\x65\x36\x00", "l>"
+
+pptest [1], "\x01\x00\x00\x00", "L<"
+pptest [258], "\x02\x01\x00\x00", "L<"
+pptest [66051], "\x03\x02\x01\x00", "L<"
+pptest [16909060], "\x04\x03\x02\x01", "L<"
+pptest [16909060], "\x01\x02\x03\x04", "L>"
+
+packtest [-1], "\xff\xff\xff\xff", "L<"
+
+pptest [1000000000], "\x00\x00\x00\x00\x3b\x9a\xca\x00", "q>"
+pptest [-1000000000], "\xff\xff\xff\xff\xc4\x65\x36\x00", "q>"
+
+if (2**33).is_a? Fixnum
+  pptest [81985529216486895],    "\x01\x23\x45\x67\x89\xab\xcd\xef", "q>"
+  pptest [-1167088121787636991], "\x01\x23\x45\x67\x89\xab\xcd\xef", "q<"
+end
+
+pptest [16909060], "\x01\x02\x03\x04", "N"
+pptest [258], "\x01\x02", "n"
+pptest [32769], "\x80\x01", "n"
+
+pptest [16909060], "\x04\x03\x02\x01", "V"
+pptest [258], "\x02\x01", "v"
+
+packtest [""], "", "m"
+packtest ["a"], "YQ==\n", "m"
+packtest ["ab"], "YWI=\n", "m"
+packtest ["abc"], "YWJj\n", "m"
+packtest ["abcd"], "YWJjZA==\n", "m"
+
+unpacktest [""], "", "m"
+unpacktest ["a"], "YQ==\n", "m"
+unpacktest ["ab"], "YWI=\n", "m"
+unpacktest ["abc"], "YWJj\n", "m"
+unpacktest ["abcd"], "YWJjZA==\n", "m"
+
+packtest [""], "\0", "H"
+packtest ["3"], "0", "H"
+packtest ["34"], "", "H0"
+packtest ["34"], "0", "H"
+packtest ["34"], "4", "H2"
+packtest ["34"], "4\0", "H3"
+packtest ["3456"], "4P", "H3"
+packtest ["34563"], "4V0", "H*"
+packtest ["5a"], "Z", "H*"
+packtest ["5A"], "Z", "H*"
+
+unpacktest [""], "", "H"
+unpacktest [""], "0", "H0"
+unpacktest ["3"], "0", "H"
+unpacktest ["30"], "0", "H2"
+unpacktest ["30"], "0", "H3"
+unpacktest ["303"], "01", "H3"
+unpacktest ["303132"], "012", "H*"
+unpacktest ["3031", 50], "012", "H4C"
+unpacktest ["5a"], "Z", "H*"
+
+packtest [""], "\0", "h"
+packtest ["3"], "\03", "h"
+packtest ["34"], "", "h0"
+packtest ["34"], "\03", "h"
+packtest ["34"], "C", "h2"
+packtest ["34"], "C\0", "h3"
+packtest ["3456"], "C\05", "h3"
+packtest ["34563"], "Ce\03", "h*"
+
+packtest   [""],    " ",   "A"
+unpacktest [""],    "",    "A"
+pptest     ["1"],   "1",   "A"
+pptest     ["1"],   "1 ",  "A2"
+unpacktest ["1"],   "1",   "A2"
+unpacktest ["1"],   "1 ",  "A2"
+unpacktest ["1"],   "1\0", "A2"
+packtest   ["12"],  "1",   "A"
+unpacktest ["1"],   "12",  "A"
+pptest     ["123"], "123", "A*"
+packtest   ["1","2"], "2", "A0A"
+unpacktest ["","2"],  "2", "A0A"
+
+packtest   [""],    "\0",  "a"
+unpacktest [""],    "",    "a"
+pptest     ["1"],   "1",   "a"
+pptest     ["1 "],  "1 ",  "a2"
+pptest     ["1\0"], "1\0", "a2"
+packtest   ["1"],   "1\0", "a2"
+pptest     ["123"], "123", "a*"
+
+packtest   [""],    "\0",    "Z"
+unpacktest [""],    "",      "Z"
+pptest     ["1"],   "1",     "Z"
+pptest     ["1"],   "1\0",   "Z2"
+pptest     ["1 "],  "1 ",    "Z2"
+pptest     ["123"], "123\0", "Z*"
+pptest     ["1","2"], "12",      "ZZ"
+pptest     ["1","2"], "1\0002",  "Z*Z"
+unpacktest ["1","3"], "1\00023", "Z3Z"
+
+packtest   [1, 2], "\x01\x02", "CyC"
+
+packtest   [65], "A", 'U'
+packtest   [59411], "\xEE\xA0\x93", 'U'
+
+pptest     [1], "\x00\x01", "xC"
+unpacktest [2], "\xcc\x02", "xC"

mrbgems/mruby-pack/run_test.rb

+#!/usr/bin/env ruby
+#
+# mrbgems test runner
+#
+
+gemname = File.basename(File.dirname(File.expand_path __FILE__))
+
+if __FILE__ == $0
+  repository, dir = 'https://github.com/mruby/mruby.git', 'tmp/mruby'
+  build_args = ARGV
+  build_args = ['all', 'test']  if build_args.nil? or build_args.empty?
+
+  Dir.mkdir 'tmp'  unless File.exist?('tmp')
+  unless File.exist?(dir)
+    system "git clone #{repository} #{dir}"
+  end
+
+  exit system(%Q[cd #{dir}; MRUBY_CONFIG=#{File.expand_path __FILE__} ruby minirake #{build_args.join(' ')}])
+end
+
+MRuby::Build.new do |conf|
+  toolchain :gcc
+  conf.gembox 'default'
+
+  conf.gem File.expand_path(File.dirname(__FILE__))
+end

mrbgems/mruby-pack/src/pack.c

+/*
+ ** pack.c - Array#pack, String#unpack
+ */
+
+#include "mruby.h"
+#include "error.h"
+#include "mruby/array.h"
+#include "mruby/class.h"
+#include "mruby/numeric.h"
+#include "mruby/string.h"
+#include "mruby/variable.h"
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+struct tmpl {
+  mrb_value str;
+  int idx;
+};
+
+enum {
+  PACK_DIR_CHAR,      /* C */
+  PACK_DIR_SHORT,     /* S */
+  PACK_DIR_LONG,      /* L */
+  PACK_DIR_QUAD,      /* Q */
+  //PACK_DIR_INT,     /* i */
+  //PACK_DIR_VAX,
+  PACK_DIR_UTF8,      /* U */
+  //PACK_DIR_BER,
+  PACK_DIR_DOUBLE,    /* E */
+  PACK_DIR_FLOAT,     /* f */
+  PACK_DIR_STR,       /* A */
+  PACK_DIR_HEX,       /* h */
+  PACK_DIR_BASE64,    /* m */
+  PACK_DIR_NUL,       /* x */
+  PACK_DIR_INVALID
+};
+
+enum {
+  PACK_TYPE_INTEGER,
+  PACK_TYPE_FLOAT,
+  PACK_TYPE_STRING,
+  PACK_TYPE_NONE
+};
+
+#define PACK_FLAG_s             0x00000001	/* native size ("_" "!") */
+#define PACK_FLAG_a             0x00000002	/* null padding ("a") */
+#define PACK_FLAG_Z             0x00000004	/* append nul char ("z") */
+#define PACK_FLAG_SIGNED        0x00000008	/* native size ("_" "!") */
+#define PACK_FLAG_GT            0x00000010	/* big endian (">") */
+#define PACK_FLAG_LT            0x00000020	/* little endian ("<") */
+#define PACK_FLAG_WIDTH         0x00000040	/* "count" is "width" */
+#define PACK_FLAG_LSB           0x00000080	/* LSB / low nibble first */
+#define PACK_FLAG_COUNT2        0x00000100	/* "count" is special... */
+#define PACK_FLAG_LITTLEENDIAN  0x00000200	/* little endian actually */
+
+#define PACK_BASE64_IGNORE	0xff
+#define PACK_BASE64_PADDING	0xfe
+
+static int littleendian = 0;
+
+const static unsigned char base64chars[] =
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static signed char base64_dec_tab[128];
+
+
+static int
+check_little_endian(void)
+{
+  unsigned int n = 1;
+  return (*(unsigned char *)&n == 1);
+}
+
+static unsigned int
+hex2int(unsigned char ch)
+{
+  if (ch >= '0' && ch <= '9')
+    return ch - '0';
+  else if (ch >= 'A' && ch <= 'F')
+    return 10 + (ch - 'A');
+  else if (ch >= 'a' && ch <= 'f')
+    return 10 + (ch - 'a');
+  else
+    return 0;
+}
+
+static void
+make_base64_dec_tab(void)
+{
+  int i;
+  memset(base64_dec_tab, PACK_BASE64_IGNORE, sizeof(base64_dec_tab));
+  for (i = 0; i < 26; i++)
+    base64_dec_tab['A' + i] = i;
+  for (i = 0; i < 26; i++)
+    base64_dec_tab['a' + i] = i + 26;
+  for (i = 0; i < 10; i++)
+    base64_dec_tab['0' + i] = i + 52;
+  base64_dec_tab['+'] = 62;
+  base64_dec_tab['/'] = 63;
+  base64_dec_tab['='] = PACK_BASE64_PADDING;
+}
+
+static mrb_value
+str_len_ensure(mrb_state *mrb, mrb_value str, int len)
+{
+  int n = RSTRING_LEN(str);
+  if (len > n) {
+    do {
+      n *= 2;
+    } while (len > n);
+    str = mrb_str_resize(mrb, str, n);
+  }
+  return str;
+}
+
+
+static int
+pack_c(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  str = str_len_ensure(mrb, str, sidx + 1);
+  RSTRING_PTR(str)[sidx] = mrb_fixnum(o);
+  return 1;
+}
+
+static int
+unpack_c(mrb_state *mrb, const void *src, int srclen, mrb_value ary, unsigned int flags)
+{
+  if (flags & PACK_FLAG_SIGNED)
+    mrb_ary_push(mrb, ary, mrb_fixnum_value(*(signed char *)src));
+  else
+    mrb_ary_push(mrb, ary, mrb_fixnum_value(*(unsigned char *)src));
+  return 1;
+}
+
+static int
+pack_s(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  unsigned short n;
+
+  str = str_len_ensure(mrb, str, sidx + 2);
+  n = mrb_fixnum(o);
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    RSTRING_PTR(str)[sidx+0] = n % 256;
+    RSTRING_PTR(str)[sidx+1] = n / 256;
+  } else {
+    RSTRING_PTR(str)[sidx+0] = n / 256;
+    RSTRING_PTR(str)[sidx+1] = n % 256;
+  }
+  return 2;
+}
+
+static int
+unpack_s(mrb_state *mrb, const unsigned char *src, int srclen, mrb_value ary, unsigned int flags)
+{
+  int n;
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    n = src[1] * 256 + src[0];
+  } else {
+    n = src[0] * 256 + src[1];
+  }
+  if ((flags & PACK_FLAG_SIGNED) && (n >= 0x8000)) {
+    n -= 0x10000;
+  }
+  mrb_ary_push(mrb, ary, mrb_fixnum_value(n));
+  return 2;
+}
+
+static int
+pack_l(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  unsigned long n;
+  str = str_len_ensure(mrb, str, sidx + 4);
+  n = mrb_fixnum(o);
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    RSTRING_PTR(str)[sidx+0] = n & 0xff;
+    RSTRING_PTR(str)[sidx+1] = n >> 8;
+    RSTRING_PTR(str)[sidx+2] = n >> 16;
+    RSTRING_PTR(str)[sidx+3] = n >> 24;
+  } else {
+    RSTRING_PTR(str)[sidx+0] = n >> 24;
+    RSTRING_PTR(str)[sidx+1] = n >> 16;
+    RSTRING_PTR(str)[sidx+2] = n >> 8;
+    RSTRING_PTR(str)[sidx+3] = n & 0xff;
+  }
+  return 4;
+}
+
+static int
+unpack_l(mrb_state *mrb, const unsigned char *src, int srclen, mrb_value ary, unsigned int flags)
+{
+  char msg[60];
+  uint32_t ul;
+  mrb_int n;
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    ul = (uint32_t)src[3] * 256*256*256;
+    ul += (uint32_t)src[2] *256*256;
+    ul += (uint32_t)src[1] *256;
+    ul += (uint32_t)src[0];
+  } else {
+    ul = (uint32_t)src[0] * 256*256*256;
+    ul += (uint32_t)src[1] *256*256;
+    ul += (uint32_t)src[2] *256;
+    ul += (uint32_t)src[3];
+  }
+  if (flags & PACK_FLAG_SIGNED) {
+    int32_t sl = ul;
+    if (!FIXABLE(sl)) {
+      snprintf(msg, sizeof(msg), "cannot unpack to Fixnum: %ld", (long)sl);
+      mrb_raise(mrb, E_RANGE_ERROR, msg);
+    }
+    n = sl;
+  } else {
+    if (!POSFIXABLE(ul)) {
+      snprintf(msg, sizeof(msg), "cannot unpack to Fixnum: %lu", (unsigned long)ul);
+      mrb_raise(mrb, E_RANGE_ERROR, msg);
+    }
+    n = ul;
+  }
+  mrb_ary_push(mrb, ary, mrb_fixnum_value(n));
+  return 4;
+}
+
+static int
+pack_q(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  unsigned long long n;
+  str = str_len_ensure(mrb, str, sidx + 8);
+  n = mrb_fixnum(o);
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    RSTRING_PTR(str)[sidx+0] = n & 0xff;
+    RSTRING_PTR(str)[sidx+1] = n >> 8;
+    RSTRING_PTR(str)[sidx+2] = n >> 16;
+    RSTRING_PTR(str)[sidx+3] = n >> 24;
+    RSTRING_PTR(str)[sidx+4] = n >> 32;
+    RSTRING_PTR(str)[sidx+5] = n >> 40;
+    RSTRING_PTR(str)[sidx+6] = n >> 48;
+    RSTRING_PTR(str)[sidx+7] = n >> 56;
+  } else {
+    RSTRING_PTR(str)[sidx+0] = n >> 56;
+    RSTRING_PTR(str)[sidx+1] = n >> 48;
+    RSTRING_PTR(str)[sidx+2] = n >> 40;
+    RSTRING_PTR(str)[sidx+3] = n >> 32;
+    RSTRING_PTR(str)[sidx+4] = n >> 24;
+    RSTRING_PTR(str)[sidx+5] = n >> 16;
+    RSTRING_PTR(str)[sidx+6] = n >> 8;
+    RSTRING_PTR(str)[sidx+7] = n & 0xff;
+  }
+  return 8;
+}
+
+static int
+unpack_q(mrb_state *mrb, const unsigned char *src, int srclen, mrb_value ary, unsigned int flags)
+{
+  char msg[60];
+  uint64_t ull;
+  int i, pos, step;
+  mrb_int n;
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+    pos  = 7;
+    step = -1;
+  } else {
+    pos  = 0;
+    step = 1;
+  }
+  ull = 0;
+  for (i = 0; i < 8; i++) {
+    ull = ull * 256 + (uint64_t)src[pos];
+    pos += step;
+  }
+  if (flags & PACK_FLAG_SIGNED) {
+    int64_t sll = ull;
+    if (!FIXABLE(sll)) {
+      snprintf(msg, sizeof(msg), "cannot unpack to Fixnum: %lld", (long long)sll);
+      mrb_raise(mrb, E_RANGE_ERROR, msg);
+    }
+    n = sll;
+  } else {
+    if (!POSFIXABLE(ull)) {
+      snprintf(msg, sizeof(msg), "cannot unpack to Fixnum: %llu", (unsigned long long)ull);
+      mrb_raise(mrb, E_RANGE_ERROR, msg);
+    }
+    n = ull;
+  }
+  mrb_ary_push(mrb, ary, mrb_fixnum_value(n));
+  return 8;
+}
+
+static int
+pack_double(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  int i;
+  double d;
+  uint8_t *buffer = (uint8_t *)&d;
+  str = str_len_ensure(mrb, str, sidx + 8);
+  d = mrb_float(o);
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+#ifdef MRB_ENDIAN_BIG
+    for (i = 0; i < 8; ++i) {
+      RSTRING_PTR(str)[sidx + i] = buffer[8 - i - 1];
+    }
+#else
+    memcpy(RSTRING_PTR(str) + sidx, buffer, 8);
+#endif
+  } else {
+#ifdef MRB_ENDIAN_BIG
+    memcpy(RSTRING_PTR(str) + sidx, buffer, 8);
+#else
+    for (i = 0; i < 8; ++i) {
+      RSTRING_PTR(str)[sidx + i] = buffer[8 - i - 1];
+    }
+#endif
+  }
+
+  return 8;
+}
+
+static int
+unpack_double(mrb_state *mrb, const unsigned char * src, int srclen, mrb_value ary, unsigned int flags)
+{
+  int i;
+  double d;
+  uint8_t *buffer = (uint8_t *)&d;
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+#ifdef MRB_ENDIAN_BIG
+    for (i = 0; i < 8; ++i) {
+      buffer[8 - i - 1] = src[i];
+    }
+#else
+    memcpy(buffer, src, 8);
+#endif
+  } else {
+#ifdef MRB_ENDIAN_BIG
+    memcpy(buffer, src, 8);
+#else
+    for (i = 0; i < 8; ++i) {
+      buffer[8 - i - 1] = src[i];
+    }
+#endif
+  }
+  mrb_ary_push(mrb, ary, mrb_float_value(mrb, d));
+
+  return 8;
+}
+
+static int
+pack_float(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, unsigned int flags)
+{
+  int i;
+  float f;
+  uint8_t *buffer = (uint8_t *)&f;
+  str = str_len_ensure(mrb, str, sidx + 4);
+  f = mrb_float(o);
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+#ifdef MRB_ENDIAN_BIG
+    for (i = 0; i < 4; ++i) {
+      RSTRING_PTR(str)[sidx + i] = buffer[4 - i - 1];
+    }
+#else
+    memcpy(RSTRING_PTR(str) + sidx, buffer, 4);
+#endif
+  } else {
+#ifdef MRB_ENDIAN_BIG
+    memcpy(RSTRING_PTR(str) + sidx, buffer, 4);
+#else
+    for (i = 0; i < 4; ++i) {
+      RSTRING_PTR(str)[sidx + i] = buffer[4 - i - 1];
+    }
+#endif
+  }
+
+  return 4;
+}
+
+static int
+unpack_float(mrb_state *mrb, const unsigned char * src, int srclen, mrb_value ary, unsigned int flags)
+{
+  int i;
+  float f;
+  uint8_t *buffer = (uint8_t *)&f;
+
+  if (flags & PACK_FLAG_LITTLEENDIAN) {
+#ifdef MRB_ENDIAN_BIG
+    for (i = 0; i < 4; ++i) {
+      buffer[4 - i - 1] = src[i];
+    }
+#else
+    memcpy(buffer, src, 4);
+#endif
+  } else {
+#ifdef MRB_ENDIAN_BIG
+    memcpy(buffer, src, 4);
+#else
+    for (i = 0; i < 4; ++i) {
+      buffer[4 - i - 1] = src[i];
+    }
+#endif
+  }
+  mrb_ary_push(mrb, ary, mrb_float_value(mrb, f));
+
+  return 4;
+}
+
+static int
+pack_utf8(mrb_state *mrb, mrb_value o, mrb_value str, mrb_int sidx, long count, unsigned int flags)
+{
+  char utf8[4];
+  int len;
+  unsigned long c = 0;
+
+  if (mrb_float_p(o)) {
+    goto range_error;
+  }
+  c = mrb_fixnum(o);
+
+  /* Unicode character */
+  /* from mruby-compiler gem */
+  if (c < 0x80) {
+    utf8[0] = (char)c;
+    len = 1;
+  }
+  else if (c < 0x800) {
+    utf8[0] = (char)(0xC0 | (c >> 6));
+    utf8[1] = (char)(0x80 | (c & 0x3F));
+    len = 2;
+  }
+  else if (c < 0x10000) {
+    utf8[0] = (char)(0xE0 |  (c >> 12)        );
+    utf8[1] = (char)(0x80 | ((c >>  6) & 0x3F));
+    utf8[2] = (char)(0x80 | ( c        & 0x3F));
+    len = 3;
+  }
+  else if (c < 0x200000) {
+    utf8[0] = (char)(0xF0 |  (c >> 18)        );
+    utf8[1] = (char)(0x80 | ((c >> 12) & 0x3F));
+    utf8[2] = (char)(0x80 | ((c >>  6) & 0x3F));
+    utf8[3] = (char)(0x80 | ( c        & 0x3F));
+    len = 4;
+  }
+  else {
+range_error:
+    mrb_raise(mrb, E_RANGE_ERROR, "pack(U): value out of range");
+  }
+
+  str = str_len_ensure(mrb, str, sidx + len);
+  memcpy(RSTRING_PTR(str) + sidx, utf8, len);
+
+  return len;
+}
+
+static const unsigned long utf8_limits[] = {
+  0x0,        /* 1 */
+  0x80,       /* 2 */
+  0x800,      /* 3 */
+  0x10000,    /* 4 */
+  0x200000,   /* 5 */
+  0x4000000,  /* 6 */
+  0x80000000, /* 7 */
+};
+
+static unsigned long
+utf8_to_uv(mrb_state *mrb, const char *p, long *lenp)
+{
+  int c = *p++ & 0xff;
+  unsigned long uv = c;
+  long n;
+
+  if (!(uv & 0x80)) {
+    *lenp = 1;
+    return uv;
+  }
+  if (!(uv & 0x40)) {
+    *lenp = 1;
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "malformed UTF-8 character");
+  }
+
+  if      (!(uv & 0x20)) { n = 2; uv &= 0x1f; }
+  else if (!(uv & 0x10)) { n = 3; uv &= 0x0f; }
+  else if (!(uv & 0x08)) { n = 4; uv &= 0x07; }
+  else if (!(uv & 0x04)) { n = 5; uv &= 0x03; }
+  else if (!(uv & 0x02)) { n = 6; uv &= 0x01; }
+  else {
+    *lenp = 1;
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "malformed UTF-8 character");
+  }
+  if (n > *lenp) {
+    mrb_raisef(mrb, E_ARGUMENT_ERROR, "malformed UTF-8 character (expected %S bytes, given %S bytes)",
+    mrb_fixnum_value(n), mrb_fixnum_value(*lenp));
+  }
+  *lenp = n--;
+  if (n != 0) {
+    while (n--) {
+      c = *p++ & 0xff;
+      if ((c & 0xc0) != 0x80) {
+        *lenp -= n + 1;
+        mrb_raisef(mrb, E_ARGUMENT_ERROR, "malformed UTF-8 character");
+      }
+      else {
+        c &= 0x3f;
+        uv = uv << 6 | c;
+      }
+    }
+  }
+  n = *lenp - 1;
+  if (uv < utf8_limits[n]) {
+    mrb_raisef(mrb, E_ARGUMENT_ERROR, "redundant UTF-8 sequence");
+  }
+  return uv;
+}
+
+static int
+unpack_utf8(mrb_state *mrb, const unsigned char * src, int srclen, mrb_value ary, unsigned int flags)
+{
+  unsigned long uv;
+  long lenp = srclen;
+
+  if (srclen == 0) {
+    return 1;
+  }
+  uv = utf8_to_uv(mrb, (const char *)src, &lenp);
+  mrb_ary_push(mrb, ary, mrb_fixnum_value((mrb_int)uv));
+  return (int)lenp;
+}
+
+static int
+pack_a(mrb_state *mrb, mrb_value src, mrb_value dst, mrb_int didx, long count, unsigned int flags)
+{
+  int copylen, slen, padlen;
+  char *dptr, *dptr0, pad, *sptr;
+
+  sptr = RSTRING_PTR(src);
+  slen = RSTRING_LEN(src);
+
+  if ((flags & PACK_FLAG_a) || (flags & PACK_FLAG_Z))
+    pad = '\0';
+  else
+    pad = ' ';
+
+  if (count == 0) {
+    return 0;
+  } else if (count == -1) {
+    copylen = slen;
+    padlen = (flags & PACK_FLAG_Z) ? 1 : 0;
+  } else if (count < slen) {
+    copylen = count;
+    padlen = 0;
+  } else {
+    copylen = slen;
+    padlen = count - slen;
+  }
+
+  dst = str_len_ensure(mrb, dst, didx + copylen + padlen);
+  dptr0 = dptr = RSTRING_PTR(dst) + didx;
+  memcpy(dptr, sptr, copylen);
+  dptr += copylen;
+  while (padlen-- > 0) {
+    *dptr++ = pad;
+  }
+
+  return dptr - dptr0;
+}
+
+static int
+unpack_a(mrb_state *mrb, const void *src, int slen, mrb_value ary, long count, unsigned int flags)
+{
+  mrb_value dst;
+  const char *cp, *sptr;
+  long copylen;
+
+  sptr = (const char *)src;
+  if (count != -1 && count < slen)  {
+    slen = count;
+  }
+  copylen = slen;
+
+  if (flags & PACK_FLAG_Z) {  /* "Z" */
+    if ((cp = (const char *)memchr(sptr, '\0', slen)) != NULL) {
+      copylen = cp - sptr;
+      if (count == -1) {
+        slen = copylen + 1;
+      }
+    }
+  } else if (!(flags & PACK_FLAG_a)) {  /* "A" */
+    while (copylen > 0 && (sptr[copylen - 1] == '\0' || isspace(sptr[copylen - 1]))) {
+      copylen--;
+    }
+  }
+
+  dst = mrb_str_new(mrb, sptr, copylen);
+  mrb_ary_push(mrb, ary, dst);
+  return slen;
+}
+
+
+static int
+pack_h(mrb_state *mrb, mrb_value src, mrb_value dst, mrb_int didx, long count, unsigned int flags)
+{
+  unsigned int a, ashift, b, bshift;
+  int slen;
+  char *dptr, *dptr0, *sptr;
+
+  sptr = RSTRING_PTR(src);
+  slen = RSTRING_LEN(src);
+
+  if (flags & PACK_FLAG_LSB) {
+    ashift = 0;
+    bshift = 4;
+  } else {
+    ashift = 4;
+    bshift = 0;
+  }
+
+  if (count == -1) {
+    count = slen;
+  } else if (slen > count) {
+    slen = count;
+  }
+
+  dst = str_len_ensure(mrb, dst, didx + count);
+  dptr = RSTRING_PTR(dst) + didx;
+
+  dptr0 = dptr;
+  for (; count > 0; count -= 2) {
+    a = b = 0;
+    if (slen > 0) {
+      a = hex2int(*sptr++);
+      slen--;
+    }
+    if (slen > 0) {
+      b = hex2int(*sptr++);
+      slen--;
+    }
+    *dptr++ = (a << ashift) + (b << bshift);
+  }
+
+  return dptr - dptr0;
+}
+
+static int
+unpack_h(mrb_state *mrb, const void *src, int slen, mrb_value ary, int count, unsigned int flags)
+{
+  mrb_value dst;
+  int a, ashift, b, bshift;
+  const char *sptr, *sptr0;
+  char *dptr, *dptr0;
+  const char hexadecimal[] = "0123456789abcdef";
+
+  if (flags & PACK_FLAG_LSB) {
+    ashift = 0;
+    bshift = 4;
+  } else {
+    ashift = 4;
+    bshift = 0;
+  }
+
+  sptr = (const char *)src;
+
+  if (count == -1)
+    count = slen * 2;
+
+  dst = mrb_str_new(mrb, NULL, count);
+  dptr = RSTRING_PTR(dst);
+
+  sptr0 = sptr;
+  dptr0 = dptr;
+  while (slen > 0 && count > 0) {
+    a = (*sptr >> ashift) & 0x0f;
+    b = (*sptr >> bshift) & 0x0f;
+    sptr++;
+    slen--;
+
+    *dptr++ = hexadecimal[a];
+    count--;
+
+    if (count > 0) {
+      *dptr++ = hexadecimal[b];
+      count--;
+    }
+  }
+
+  dst = mrb_str_resize(mrb, dst, dptr - dptr0);
+  mrb_ary_push(mrb, ary, dst);
+  return sptr - sptr0;
+}
+
+
+static int
+pack_m(mrb_state *mrb, mrb_value src, mrb_value dst, mrb_int didx, long count, unsigned int flags)
+{
+  mrb_int dstlen;
+  unsigned long l;
+  int column, srclen;
+  char *srcptr, *dstptr, *dstptr0;
+
+  srcptr = RSTRING_PTR(src);
+  srclen = RSTRING_LEN(src);
+
+  if (srclen == 0)  /* easy case */
+    return 0;
+
+  if (count != 0 && count < 3) {  /* -1, 1 or 2 */
+    count = 45;
+  } else if (count >= 3) {
+    count -= count % 3;
+  }
+
+  dstlen = srclen / 3 * 4;
+  if (count > 0) {
+    dstlen += (srclen / count) + ((srclen % count) == 0 ? 0 : 1);
+  }
+  dst = str_len_ensure(mrb, dst, didx + dstlen);
+  dstptr = RSTRING_PTR(dst) + didx;
+
+  dstptr0 = dstptr;
+  for (column = 3; srclen >= 3; srclen -= 3, column += 3) {
+    l = (unsigned char)*srcptr++ << 16;
+    l += (unsigned char)*srcptr++ << 8;
+    l += (unsigned char)*srcptr++;
+
+    *dstptr++ = base64chars[(l >> 18) & 0x3f];
+    *dstptr++ = base64chars[(l >> 12) & 0x3f];
+    *dstptr++ = base64chars[(l >>  6) & 0x3f];
+    *dstptr++ = base64chars[ l        & 0x3f];
+
+    if (column == count) {
+      *dstptr++ = '\n';
+      column = 0;
+    }
+  }
+  if (srclen == 1) {
+    l = (unsigned char)*srcptr++ << 16;
+    *dstptr++ = base64chars[(l >> 18) & 0x3f];
+    *dstptr++ = base64chars[(l >> 12) & 0x3f];
+    *dstptr++ = '=';
+    *dstptr++ = '=';
+    column += 3;
+  } else if (srclen == 2) {
+    l = (unsigned char)*srcptr++ << 16;
+    l += (unsigned char)*srcptr++ << 8;
+    *dstptr++ = base64chars[(l >> 18) & 0x3f];
+    *dstptr++ = base64chars[(l >> 12) & 0x3f];
+    *dstptr++ = base64chars[(l >>  6) & 0x3f];
+    *dstptr++ = '=';
+    column += 3;
+  }
+  if (column > 0 && count > 0) {
+    *dstptr++ = '\n';
+  }
+
+  return dstptr - dstptr0;
+}
+
+static int
+unpack_m(mrb_state *mrb, const void *src, int slen, mrb_value ary, unsigned int flags)
+{
+  mrb_value dst;
+  int dlen;
+  unsigned long l;
+  int i, padding;
+  unsigned char c, ch[4];
+  const char *sptr, *sptr0;
+  char *dptr, *dptr0;
+
+  sptr0 = sptr = (const char *)src;
+
+  dlen = slen / 4 * 3;  /* an estimated value - may be shorter */
+  dst = mrb_str_new(mrb, NULL, dlen);
+  dptr0 = dptr = RSTRING_PTR(dst);
+
+  padding = 0;
+  while (slen >= 4) {
+    for (i = 0; i < 4; i++) {
+      do {
+        if (slen-- == 0)
+          goto done;
+        c = *sptr++;
+	if (c >= sizeof(base64_dec_tab))
+	  continue;
+	ch[i] = base64_dec_tab[c];
+	if (ch[i] == PACK_BASE64_PADDING) {
+	  ch[i] = 0;
+	  padding++;
+	}
+      } while (ch[i] == PACK_BASE64_IGNORE);
+    }
+
+    l = (ch[0] << 18) + (ch[1] << 12) + (ch[2] << 6) + ch[3];
+
+    if (padding == 0) {
+      *dptr++ = (l >> 16) & 0xff;
+      *dptr++ = (l >> 8) & 0xff;
+      *dptr++ = l & 0xff;
+    } else if (padding == 1) {
+      *dptr++ = (l >> 16) & 0xff;
+      *dptr++ = (l >> 8) & 0xff;
+      break;
+    } else {
+      *dptr++ = (l >> 16) & 0xff;
+      break;
+    }
+  }
+
+done:
+  dst = mrb_str_resize(mrb, dst, dptr - dptr0);
+  mrb_ary_push(mrb, ary, dst);
+  return sptr - sptr0;
+}
+
+static int
+pack_x(mrb_state *mrb, mrb_value src, mrb_value dst, mrb_int didx, long count, unsigned int flags)
+{
+  long i;
+
+  dst = str_len_ensure(mrb, dst, didx + count);
+  for (i = 0; i < count; i++) {
+    RSTRING_PTR(dst)[didx] = '\0';
+  }
+  return count;
+}
+
+static int
+unpack_x(mrb_state *mrb, const void *src, int slen, mrb_value ary, int count, unsigned int flags)
+{
+  if (slen < count) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "x outside of string");
+  }
+  return count;
+}
+
+static void
+prepare_tmpl(mrb_state *mrb, struct tmpl *tmpl)
+{
+  mrb_get_args(mrb, "S", &tmpl->str);
+  tmpl->idx = 0;
+}
+
+static int
+has_tmpl(const struct tmpl *tmpl)
+{
+  return (tmpl->idx < RSTRING_LEN(tmpl->str));
+}
+
+static void
+read_tmpl(mrb_state *mrb, struct tmpl *tmpl, int *dirp, int *typep, int *sizep, long *countp, unsigned int *flagsp)
+{
+  int ch, dir, t, tlen, type;
+  int size = 0;
+  long count = 1;
+  unsigned int flags = 0;
+  const char *tptr;
+
+  tptr = RSTRING_PTR(tmpl->str);
+  tlen = RSTRING_LEN(tmpl->str);
+
+  t = tptr[tmpl->idx++];
+alias:
+  switch (t) {
+  case 'A':
+    dir = PACK_DIR_STR;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_WIDTH | PACK_FLAG_COUNT2;
+    break;
+  case 'a':
+    dir = PACK_DIR_STR;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_WIDTH | PACK_FLAG_COUNT2 | PACK_FLAG_a;
+    break;
+  case 'C':
+    dir = PACK_DIR_CHAR;
+    type = PACK_TYPE_INTEGER;
+    size = 1;
+    break;
+  case 'c':
+    dir = PACK_DIR_CHAR;
+    type = PACK_TYPE_INTEGER;
+    size = 1;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'D': case 'd':
+    dir = PACK_DIR_DOUBLE;
+    type = PACK_TYPE_FLOAT;
+    size = 8;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'F': case 'f':
+    dir = PACK_DIR_FLOAT;
+    type = PACK_TYPE_FLOAT;
+    size = 4;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'E':
+    dir = PACK_DIR_DOUBLE;
+    type = PACK_TYPE_FLOAT;
+    size = 8;
+    flags |= PACK_FLAG_SIGNED | PACK_FLAG_LT;
+    break;
+  case 'e':
+    dir = PACK_DIR_FLOAT;
+    type = PACK_TYPE_FLOAT;
+    size = 4;
+    flags |= PACK_FLAG_SIGNED | PACK_FLAG_LT;
+    break;
+  case 'G':
+    dir = PACK_DIR_DOUBLE;
+    type = PACK_TYPE_FLOAT;
+    size = 8;
+    flags |= PACK_FLAG_SIGNED | PACK_FLAG_GT;
+    break;
+  case 'g':
+    dir = PACK_DIR_FLOAT;
+    type = PACK_TYPE_FLOAT;
+    size = 4;
+    flags |= PACK_FLAG_SIGNED | PACK_FLAG_GT;
+    break;
+  case 'H':
+    dir = PACK_DIR_HEX;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_COUNT2;
+    break;
+  case 'h':
+    dir = PACK_DIR_HEX;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_COUNT2 | PACK_FLAG_LSB;
+    break;
+  case 'I':
+    switch (sizeof(int)) {
+      case 2: t = 'S'; goto alias;
+      case 4: t = 'L'; goto alias;
+      case 8: t = 'Q'; goto alias;
+      default:
+        mrb_raisef(mrb, E_RUNTIME_ERROR, "mruby-pack does not support sizeof(int) == %S", mrb_fixnum_value(sizeof(int)));
+    }
+    break;
+  case 'i':
+    switch (sizeof(int)) {
+      case 2: t = 's'; goto alias;
+      case 4: t = 'l'; goto alias;
+      case 8: t = 'q'; goto alias;
+      default:
+        mrb_raisef(mrb, E_RUNTIME_ERROR, "mruby-pack does not support sizeof(int) == %S", mrb_fixnum_value(sizeof(int)));
+    }
+    break;
+  case 'L':
+    dir = PACK_DIR_LONG;
+    type = PACK_TYPE_INTEGER;
+    size = 4;
+    break;
+  case 'l':
+    dir = PACK_DIR_LONG;
+    type = PACK_TYPE_INTEGER;
+    size = 4;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'm':
+    dir = PACK_DIR_BASE64;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_WIDTH;
+    break;
+  case 'N':  /* = "L>" */
+    dir = PACK_DIR_LONG;
+    type = PACK_TYPE_INTEGER;
+    size = 4;
+    flags |= PACK_FLAG_GT;
+    break;
+  case 'n':  /* = "S>" */
+    dir = PACK_DIR_SHORT;
+    type = PACK_TYPE_INTEGER;
+    size = 2;
+    flags |= PACK_FLAG_GT;
+    break;
+  case 'Q':
+    dir = PACK_DIR_QUAD;
+    type = PACK_TYPE_INTEGER;
+    size = 8;
+    break;
+  case 'q':
+    dir = PACK_DIR_QUAD;
+    type = PACK_TYPE_INTEGER;
+    size = 8;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'S':
+    dir = PACK_DIR_SHORT;
+    type = PACK_TYPE_INTEGER;
+    size = 2;
+    break;
+  case 's':
+    dir = PACK_DIR_SHORT;
+    type = PACK_TYPE_INTEGER;
+    size = 2;
+    flags |= PACK_FLAG_SIGNED;
+    break;
+  case 'U':
+    dir = PACK_DIR_UTF8;
+    type = PACK_TYPE_INTEGER;
+    break;
+  case 'V':  /* = "L<" */
+    dir = PACK_DIR_LONG;
+    type = PACK_TYPE_INTEGER;
+    size = 4;
+    flags |= PACK_FLAG_LT;
+    break;
+  case 'v':  /* = "S<" */
+    dir = PACK_DIR_SHORT;
+    type = PACK_TYPE_INTEGER;
+    size = 2;
+    flags |= PACK_FLAG_LT;
+    break;
+  case 'x':
+    dir = PACK_DIR_NUL;
+    type = PACK_TYPE_NONE;
+    break;
+  case 'Z':
+    dir = PACK_DIR_STR;
+    type = PACK_TYPE_STRING;
+    flags |= PACK_FLAG_WIDTH | PACK_FLAG_COUNT2 | PACK_FLAG_Z;
+    break;
+  default:
+    dir = PACK_DIR_INVALID;
+    type = PACK_TYPE_NONE;
+    break;
+  }
+
+  /* read suffix [0-9*_!<>] */
+  while (tmpl->idx < tlen) {
+    ch = tptr[tmpl->idx++];
+    if (isdigit(ch)) {
+      count = ch - '0';
+      while (tmpl->idx < tlen && isdigit(tptr[tmpl->idx])) {
+        count = count * 10 + (tptr[tmpl->idx++] - '0');
+      }
+      continue;  /* special case */
+    } else if (ch == '*')  {
+      count = -1;
+    } else if (ch == '_' || ch == '!' || ch == '<' || ch == '>') {
+      if (strchr("sSiIlLqQ", t) == NULL) {
+        char ch_str = ch;
+        mrb_raisef(mrb, E_ARGUMENT_ERROR, "'%S' allowed only after types sSiIlLqQ", mrb_str_new(mrb, &ch_str, 1));
+      }
+      if (ch == '_' || ch == '!') {
+        flags |= PACK_FLAG_s;
+      } else if (ch == '<') {
+        flags |= PACK_FLAG_LT;
+      } else if (ch == '>') {
+        flags |= PACK_FLAG_GT;
+      }
+    } else {
+      tmpl->idx--;
+      break;
+    }
+  }
+
+  if ((flags & PACK_FLAG_LT) || (!(flags & PACK_FLAG_GT) && littleendian)) {
+    flags |= PACK_FLAG_LITTLEENDIAN;
+  }
+
+  *dirp = dir;
+  *typep = type;
+  *sizep = size;
+  *countp = count;
+  *flagsp = flags;
+}
+
+static mrb_value
+mrb_pack_pack(mrb_state *mrb, mrb_value ary)
+{
+  mrb_value o, result;
+  mrb_int aidx;
+  struct tmpl tmpl;
+  long count;
+  unsigned int flags;
+  int dir, ridx, size, type;
+
+  prepare_tmpl(mrb, &tmpl);
+
+  result = mrb_str_new(mrb, NULL, 128);  /* allocate initial buffer */
+  aidx = 0;
+  ridx = 0;
+  while (has_tmpl(&tmpl)) {
+    read_tmpl(mrb, &tmpl, &dir, &type, &size, &count, &flags);
+
+    if (dir == PACK_DIR_INVALID)
+      continue;
+    else if (dir == PACK_DIR_NUL) {
+        ridx += pack_x(mrb, mrb_nil_value(), result, ridx, count, flags);
+        continue;
+    }
+
+    for (; aidx < RARRAY_LEN(ary); aidx++) {
+      if (count == 0 && !(flags & PACK_FLAG_WIDTH))
+        break;
+
+      o = mrb_ary_ref(mrb, ary, aidx);
+      if (type == PACK_TYPE_INTEGER) {
+        o = mrb_to_int(mrb, o);
+      } else if (type == PACK_TYPE_FLOAT) {
+        if (!mrb_float_p(o)) {
+          o = mrb_funcall(mrb, o, "to_f", 0);
+        }
+      } else if (type == PACK_TYPE_STRING) {
+        if (!mrb_string_p(o)) {
+          mrb_raisef(mrb, E_TYPE_ERROR, "can't convert %S into String", mrb_class_path(mrb, mrb_obj_class(mrb, o)));
+        }
+      }
+
+      switch (dir) {
+      case PACK_DIR_CHAR:
+        ridx += pack_c(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_SHORT:
+        ridx += pack_s(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_LONG:
+        ridx += pack_l(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_QUAD:
+        ridx += pack_q(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_BASE64:
+        ridx += pack_m(mrb, o, result, ridx, count, flags);
+        break;
+      case PACK_DIR_HEX:
+        ridx += pack_h(mrb, o, result, ridx, count, flags);
+        break;
+      case PACK_DIR_STR:
+        ridx += pack_a(mrb, o, result, ridx, count, flags);
+        break;
+      case PACK_DIR_DOUBLE:
+        ridx += pack_double(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_FLOAT:
+        ridx += pack_float(mrb, o, result, ridx, flags);
+        break;
+      case PACK_DIR_UTF8:
+        ridx += pack_utf8(mrb, o, result, ridx, count, flags);
+        break;
+      default:
+        break;
+      }
+      if (dir == PACK_DIR_STR) { /* always consumes 1 entry */
+        aidx++;
+        break;
+      }
+      if (count > 0) {
+        count--;
+      }
+    }
+  }
+
+  mrb_str_resize(mrb, result, ridx);
+  return result;
+}
+
+static mrb_value
+mrb_pack_unpack(mrb_state *mrb, mrb_value str)
+{
+  mrb_value result;
+  struct tmpl tmpl;
+  long count;
+  unsigned int flags;
+  int dir, size, srcidx, srclen, type;
+  const unsigned char *sptr;
+
+  prepare_tmpl(mrb, &tmpl);
+
+  srcidx = 0;
+  srclen = RSTRING_LEN(str);
+
+  result = mrb_ary_new(mrb);
+  while (has_tmpl(&tmpl)) {
+    read_tmpl(mrb, &tmpl, &dir, &type, &size, &count, &flags);
+
+    if (dir == PACK_DIR_INVALID)
+      continue;
+    else if (dir == PACK_DIR_NUL) {
+      srcidx += unpack_x(mrb, sptr, srclen - srcidx, result, count, flags);
+      continue;
+    }
+
+    if (flags & PACK_FLAG_COUNT2) {
+      sptr = (const unsigned char *)RSTRING_PTR(str) + srcidx;
+      switch (dir) {
+      case PACK_DIR_HEX:
+        srcidx += unpack_h(mrb, sptr, srclen - srcidx, result, count, flags);
+        break;
+      case PACK_DIR_STR:
+        srcidx += unpack_a(mrb, sptr, srclen - srcidx, result, count, flags);
+        break;
+      }
+      continue;
+    }
+
+    while (count != 0) {
+      if (srclen - srcidx < size) {
+        while (count-- > 0) {
+          mrb_ary_push(mrb, result, mrb_nil_value());
+        }
+        break;
+      }
+
+      sptr = (const unsigned char *)RSTRING_PTR(str) + srcidx;
+      switch (dir) {
+      case PACK_DIR_CHAR:
+        srcidx += unpack_c(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_SHORT:
+        srcidx += unpack_s(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_LONG:
+        srcidx += unpack_l(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_QUAD:
+        srcidx += unpack_q(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_BASE64:
+        srcidx += unpack_m(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_FLOAT:
+        srcidx += unpack_float(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_DOUBLE:
+        srcidx += unpack_double(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      case PACK_DIR_UTF8:
+        srcidx += unpack_utf8(mrb, sptr, srclen - srcidx, result, flags);
+        break;
+      default:
+        mrb_raise(mrb, E_RUNTIME_ERROR, "mruby-pack's bug");
+      }
+      if (count > 0) {
+        count--;
+      }
+    }
+  }
+
+  return result;
+}
+
+void
+mrb_mruby_pack_gem_init(mrb_state *mrb)
+{
+  littleendian = check_little_endian();
+  make_base64_dec_tab();
+
+  mrb_define_method(mrb, mrb->array_class, "pack", mrb_pack_pack, MRB_ARGS_REQ(1));
+  mrb_define_method(mrb, mrb->string_class, "unpack", mrb_pack_unpack, MRB_ARGS_REQ(1));
+}
+
+void
+mrb_mruby_pack_gem_final(mrb_state *mrb)
+{
+}

mrbgems/mruby-pack/test/pack.rb

+# pack & unpack 'm' (base64)
+assert('[""].pack("m")') do
+  ary = ""
+  str = ""
+  [ary].pack("m") == str and
+  str.unpack("m") == [ary]
+end
+
+assert('["\0"].pack("m")') do
+  ary = "\0"
+  str = "AA==\n"
+  [ary].pack("m") == str and
+  str.unpack("m") == [ary]
+end
+
+assert('["\0\0"].pack("m")') do
+  ary = "\0\0"
+  str = "AAA=\n"
+  [ary].pack("m") == str and
+  str.unpack("m") == [ary]
+end
+
+assert('["\0\0\0"].pack("m")') do
+  ary = "\0\0\0"
+  str = "AAAA\n"
+  [ary].pack("m") == str and
+  str.unpack("m") == [ary]
+end
+
+assert('["abc..xyzABC..XYZ"].pack("m")') do
+  ["abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"].pack("m") == "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNERUZHSElKS0xNTk9QUVJT\nVFVWV1hZWg==\n"
+end
+
+assert('"YWJ...".unpack("m") should "abc..xyzABC..XYZ"') do
+  str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+  "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNERUZHSElKS0xNTk9QUVJT\nVFVWV1hZWg==\n".unpack("m") == [str] and
+  "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWg==\n".unpack("m") == [str]
+end
+
+# pack & unpack 'H'
+assert('["3031"].pack("H*")') do
+  ary = "3031"
+  str = "01"
+  [ary].pack("H*") == str and
+  str.unpack("H*") == [ary]
+end
+
+assert('["10"].pack("H*")') do
+  ary = "10"
+  str = "\020"
+  [ary].pack("H*") == str and
+  str.unpack("H*") == [ary]
+end
+
+assert('[0,1,127,128,255].pack("C*")') do
+ ary = [ 0, 1, 127, 128, 255 ]
+ str = "\x00\x01\x7F\x80\xFF"
+ ary.pack("C*") == str and str.unpack("C*") == ary
+end
+
+# pack "a"
+assert('["abc"].pack("a")') do
+  ["abc"].pack("a") == "a" and
+  ["abc"].pack("a*") == "abc" and
+  ["abc"].pack("a4") == "abc\0"
+end
+
+# upack "a"
+assert('["abc"].pack("a")') do
+  "abc\0".unpack("a4") == ["abc\0"] and
+  "abc ".unpack("a4") == ["abc "]
+end
+
+# pack "A"
+assert('["abc"].pack("A")') do
+  ["abc"].pack("A") == "a" and
+  ["abc"].pack("A*") == "abc" and
+  ["abc"].pack("A4") == "abc "
+end
+
+# upack "A"
+assert('["abc"].pack("A")') do
+  "abc\0".unpack("A4") == ["abc"] and
+  "abc ".unpack("A4") == ["abc"]
+end
+
+# regression tests
+assert('issue #1') do
+  [1, 2].pack("nn") == "\000\001\000\002"
+end
+
+def assert_pack tmpl, packed, unpacked
+  assert_equal packed, unpacked.pack(tmpl)
+  assert_equal unpacked, packed.unpack(tmpl)
+end
+
+PACK_IS_LITTLE_ENDIAN = "\x01\00".unpack('S')[0] == 0x01
+
+assert 'pack float' do
+  assert_pack 'e', "\x00\x00@@", [3.0]
+  assert_pack 'g', "@@\x00\x00", [3.0]
+
+  if PACK_IS_LITTLE_ENDIAN
+    assert_pack 'f', "\x00\x00@@", [3.0]
+    assert_pack 'F', "\x00\x00@@", [3.0]
+  else
+    assert_pack 'f', "@@\x00\x00", [3.0]
+    assert_pack 'F', "@@\x00\x00", [3.0]
+  end
+end
+
+assert 'pack double' do
+  assert_pack 'E', "\x00\x00\x00\x00\x00\x00\b@", [3.0]
+  assert_pack 'G', "@\b\x00\x00\x00\x00\x00\x00", [3.0]
+
+  if PACK_IS_LITTLE_ENDIAN
+    assert_pack 'd', "\x00\x00\x00\x00\x00\x00\b@", [3.0]
+    assert_pack 'D', "\x00\x00\x00\x00\x00\x00\b@", [3.0]
+  else
+    assert_pack 'd', "@\b\x00\x00\x00\x00\x00\x00", [3.0]
+    assert_pack 'D', "@\b\x00\x00\x00\x00\x00\x00", [3.0]
+  end
+end
+
+assert 'pack/unpack "i"' do
+  int_size = [0].pack('i').size
+  raise "pack('i').size is too small (#{int_size})" if int_size < 2
+
+  if PACK_IS_LITTLE_ENDIAN
+    str = "\xC7\xCF" + "\xFF" * (int_size-2)
+  else
+    str = "\xFF" * (int_size-2) + "\xC7\xCF"
+  end
+  assert_pack 'i', str, [-12345]
+end
+
+assert 'pack/unpack "I"' do
+  uint_size = [0].pack('I').size
+  raise "pack('I').size is too small (#{uint_size})" if uint_size < 2
+
+  if PACK_IS_LITTLE_ENDIAN
+    str = "\x39\x30" + "\0" * (uint_size-2)
+  else
+    str = "\0" * (uint_size-2) + "\x39\x30"
+  end
+  assert_pack 'I', str, [12345]
+end
+
+assert 'pack/unpack "U"' do
+  assert_equal [], "".unpack("U")
+  assert_equal [], "".unpack("U*")
+  assert_equal [65, 66], "ABC".unpack("U2")
+  assert_equal [12371, 12435, 12395, 12385, 12399, 19990, 30028], "こんにちは世界".unpack("U*")
+
+  assert_equal "", [].pack("U")
+  assert_equal "", [].pack("U*")
+  assert_equal "AB", [65, 66, 67].pack("U2")
+  assert_equal "こんにちは世界", [12371, 12435, 12395, 12385, 12399, 19990, 30028].pack("U*")
+
+  assert_equal "\000", [0].pack("U")
+
+  assert_raise(RangeError) { [-0x40000000].pack("U") }
+  assert_raise(RangeError) { [-1].pack("U") }
+  assert_raise(RangeError) { [0x40000000].pack("U") }
+end