Move src/sprintf to mrbgems/mruby-sprintf/src/

1 files changed, 1095 insertions, 0 deletions

diff --git a/mrbgems/mruby-sprintf/src/sprintf.c b/mrbgems/mruby-sprintf/src/sprintf.c
new file mode 100644
index 000000000..192d44735
--- /dev/null
+++ b/mrbgems/mruby-sprintf/src/sprintf.c
@@ -0,0 +1,1095 @@
+/*
+** sprintf.c - Kernel.#sprintf
+**
+** See Copyright Notice in mruby.h
+*/
+
+#include "mruby.h"
+
+#ifdef ENABLE_SPRINTF
+
+#include <stdio.h>
+#include <string.h>
+#include "mruby/string.h"
+#include "mruby/hash.h"
+#include "mruby/numeric.h"
+#include <math.h>
+#include <ctype.h>
+
+#ifdef _MSC_VER
+#include <float.h>
+#endif
+
+#ifdef HAVE_IEEEFP_H
+#include <ieeefp.h>
+#endif
+
+#define BIT_DIGITS(N)   (((N)*146)/485 + 1)  /* log2(10) =~ 146/485 */
+#define BITSPERDIG (sizeof(mrb_int)*CHAR_BIT)
+#define EXTENDSIGN(n, l) (((~0 << (n)) >> (((n)*(l)) % BITSPERDIG)) & ~(~0 << (n)))
+
+static void fmt_setup(char*,size_t,int,int,int,int);
+
+static char*
+remove_sign_bits(char *str, int base)
+{
+  char *t;
+
+  t = str;
+  if (base == 16) {
+    while (*t == 'f') {
+      t++;
+    }
+  }
+  else if (base == 8) {
+    *t |= EXTENDSIGN(3, strlen(t));
+    while (*t == '7') {
+      t++;
+    }
+  }
+  else if (base == 2) {
+    while (*t == '1') {
+      t++;
+    }
+  }
+
+  return t;
+}
+
+static char
+sign_bits(int base, const char *p)
+{
+  char c;
+
+  switch (base) {
+  case 16:
+    if (*p == 'X') c = 'F';
+    else c = 'f';
+    break;
+  case 8:
+    c = '7'; break;
+  case 2:
+    c = '1'; break;
+  default:
+    c = '.'; break;
+  }
+  return c;
+}
+
+static mrb_value
+mrb_fix2binstr(mrb_state *mrb, mrb_value x, int base)
+{
+  char buf[64], *b = buf + sizeof buf;
+  unsigned long val = mrb_fixnum(x);
+  char d;
+
+  if (base != 2) {
+    mrb_raisef(mrb, E_ARGUMENT_ERROR, "invalid radix %d", base);
+  }
+
+  if (val >= (1 << 10))
+    val &= 0x3ff;
+
+  if (val == 0) {
+    return mrb_str_new(mrb, "0", 1);
+  }
+  *--b = '\0';
+  do {
+    *--b = mrb_digitmap[(int)(val % base)];
+  } while (val /= base);
+
+  if (mrb_fixnum(x) < 0) {
+    b = remove_sign_bits(b, base);
+    switch (base) {
+    case 16: d = 'f'; break;
+    case 8:  d = '7'; break;
+    case 2:  d = '1'; break;
+    default: d = 0;   break;
+    }
+
+    if (d && *b != d) {
+      *--b = d;
+    }
+  }
+
+  return mrb_str_new2(mrb, b);
+}
+
+#define FNONE  0
+#define FSHARP 1
+#define FMINUS 2
+#define FPLUS  4
+#define FZERO  8
+#define FSPACE 16
+#define FWIDTH 32
+#define FPREC  64
+#define FPREC0 128
+
+#define CHECK(l) do {\
+/*  int cr = ENC_CODERANGE(result);*/\
+  while (blen + (l) >= bsiz) {\
+    bsiz*=2;\
+  }\
+  mrb_str_resize(mrb, result, bsiz);\
+/*  ENC_CODERANGE_SET(result, cr);*/\
+  buf = RSTRING_PTR(result);\
+} while (0)
+
+#define PUSH(s, l) do { \
+  CHECK(l);\
+  memcpy(&buf[blen], s, l);\
+  blen += (l);\
+} while (0)
+
+#define FILL(c, l) do { \
+  CHECK(l);\
+  memset(&buf[blen], c, l);\
+  blen += (l);\
+} while (0)
+
+#define GETARG() (!mrb_undef_p(nextvalue) ? nextvalue : \
+  posarg == -1 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "unnumbered(%d) mixed with numbered", nextarg), mrb_undef_value()) : \
+  posarg == -2 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "unnumbered(%d) mixed with named", nextarg), mrb_undef_value()) : \
+  (posarg = nextarg++, GETNTHARG(posarg)))
+
+#define GETPOSARG(n) (posarg > 0 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "numbered(%d) after unnumbered(%d)", n, posarg), mrb_undef_value()) : \
+  posarg == -2 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "numbered(%d) after named", n), mrb_undef_value()) : \
+  ((n < 1) ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "invalid index - %d$", n), mrb_undef_value()) : \
+  (posarg = -1, GETNTHARG(n))))
+
+#define GETNTHARG(nth) \
+  ((nth >= argc) ? (mrb_raise(mrb, E_ARGUMENT_ERROR, "too few arguments"), mrb_undef_value()) : argv[nth])
+
+#define GETNAMEARG(id, name, len) ( \
+  posarg > 0 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "named%.*s after unnumbered(%d)", (len), (name), posarg), mrb_undef_value()) : \
+  posarg == -1 ? \
+  (mrb_raisef(mrb, E_ARGUMENT_ERROR, "named%.*s after numbered", (len), (name)), mrb_undef_value()) :    \
+  (posarg = -2, mrb_hash_fetch(mrb, get_hash(mrb, &hash, argc, argv), id, mrb_undef_value())))
+
+#define GETNUM(n, val) \
+  for (; p < end && ISDIGIT(*p); p++) {\
+    int next_n = 10 * n + (*p - '0'); \
+    if (next_n / 10 != n) {\
+      mrb_raise(mrb, E_ARGUMENT_ERROR, #val " too big"); \
+    } \
+    n = next_n; \
+  } \
+  if (p >= end) { \
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "malformed format string - %*[0-9]"); \
+  }
+
+#define GETASTER(num) do { \
+  t = p++; \
+  n = 0; \
+  GETNUM(n, val); \
+  if (*p == '$') { \
+    tmp = GETPOSARG(n); \
+  } \
+  else { \
+    tmp = GETARG(); \
+    p = t; \
+  } \
+  num = mrb_fixnum(tmp); \
+} while (0)
+
+static mrb_value
+get_hash(mrb_state *mrb, mrb_value *hash, int argc, const mrb_value *argv)
+{
+  mrb_value tmp;
+
+  if (!mrb_undef_p(*hash)) return *hash;
+  if (argc != 2) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "one hash required");
+  }
+  tmp = mrb_check_convert_type(mrb, argv[1], MRB_TT_HASH, "Hash", "to_hash");
+  if (mrb_nil_p(tmp)) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "one hash required");
+  }
+  return (*hash = tmp);
+}
+
+/*
+ *  call-seq:
+ *     format(format_string [, arguments...] )   -> string
+ *     sprintf(format_string [, arguments...] )  -> string
+ *
+ *  Returns the string resulting from applying <i>format_string</i> to
+ *  any additional arguments.  Within the format string, any characters
+ *  other than format sequences are copied to the result.
+ *
+ *  The syntax of a format sequence is follows.
+ *
+ *    %[flags][width][.precision]type
+ *
+ *  A format
+ *  sequence consists of a percent sign, followed by optional flags,
+ *  width, and precision indicators, then terminated with a field type
+ *  character.  The field type controls how the corresponding
+ *  <code>sprintf</code> argument is to be interpreted, while the flags
+ *  modify that interpretation.
+ *
+ *  The field type characters are:
+ *
+ *      Field |  Integer Format
+ *      ------+--------------------------------------------------------------
+ *        b   | Convert argument as a binary number.
+ *            | Negative numbers will be displayed as a two's complement
+ *            | prefixed with `..1'.
+ *        B   | Equivalent to `b', but uses an uppercase 0B for prefix
+ *            | in the alternative format by #.
+ *        d   | Convert argument as a decimal number.
+ *        i   | Identical to `d'.
+ *        o   | Convert argument as an octal number.
+ *            | Negative numbers will be displayed as a two's complement
+ *            | prefixed with `..7'.
+ *        u   | Identical to `d'.
+ *        x   | Convert argument as a hexadecimal number.
+ *            | Negative numbers will be displayed as a two's complement
+ *            | prefixed with `..f' (representing an infinite string of
+ *            | leading 'ff's).
+ *        X   | Equivalent to `x', but uses uppercase letters.
+ *
+ *      Field |  Float Format
+ *      ------+--------------------------------------------------------------
+ *        e   | Convert floating point argument into exponential notation
+ *            | with one digit before the decimal point as [-]d.dddddde[+-]dd.
+ *            | The precision specifies the number of digits after the decimal
+ *            | point (defaulting to six).
+ *        E   | Equivalent to `e', but uses an uppercase E to indicate
+ *            | the exponent.
+ *        f   | Convert floating point argument as [-]ddd.dddddd,
+ *            | where the precision specifies the number of digits after
+ *            | the decimal point.
+ *        g   | Convert a floating point number using exponential form
+ *            | if the exponent is less than -4 or greater than or
+ *            | equal to the precision, or in dd.dddd form otherwise.
+ *            | The precision specifies the number of significant digits.
+ *        G   | Equivalent to `g', but use an uppercase `E' in exponent form.
+ *        a   | Convert floating point argument as [-]0xh.hhhhp[+-]dd,
+ *            | which is consisted from optional sign, "0x", fraction part
+ *            | as hexadecimal, "p", and exponential part as decimal.
+ *        A   | Equivalent to `a', but use uppercase `X' and `P'.
+ *
+ *      Field |  Other Format
+ *      ------+--------------------------------------------------------------
+ *        c   | Argument is the numeric code for a single character or
+ *            | a single character string itself.
+ *        p   | The valuing of argument.inspect.
+ *        s   | Argument is a string to be substituted.  If the format
+ *            | sequence contains a precision, at most that many characters
+ *            | will be copied.
+ *        %   | A percent sign itself will be displayed.  No argument taken.
+ *
+ *  The flags modifies the behavior of the formats.
+ *  The flag characters are:
+ *
+ *    Flag     | Applies to    | Meaning
+ *    ---------+---------------+-----------------------------------------
+ *    space    | bBdiouxX      | Leave a space at the start of
+ *             | aAeEfgG       | non-negative numbers.
+ *             | (numeric fmt) | For `o', `x', `X', `b' and `B', use
+ *             |               | a minus sign with absolute value for
+ *             |               | negative values.
+ *    ---------+---------------+-----------------------------------------
+ *    (digit)$ | all           | Specifies the absolute argument number
+ *             |               | for this field.  Absolute and relative
+ *             |               | argument numbers cannot be mixed in a
+ *             |               | sprintf string.
+ *    ---------+---------------+-----------------------------------------
+ *     #       | bBoxX         | Use an alternative format.
+ *             | aAeEfgG       | For the conversions `o', increase the precision
+ *             |               | until the first digit will be `0' if
+ *             |               | it is not formatted as complements.
+ *             |               | For the conversions `x', `X', `b' and `B'
+ *             |               | on non-zero, prefix the result with ``0x'',
+ *             |               | ``0X'', ``0b'' and ``0B'', respectively.
+ *             |               | For `a', `A', `e', `E', `f', `g', and 'G',
+ *             |               | force a decimal point to be added,
+ *             |               | even if no digits follow.
+ *             |               | For `g' and 'G', do not remove trailing zeros.
+ *    ---------+---------------+-----------------------------------------
+ *    +        | bBdiouxX      | Add a leading plus sign to non-negative
+ *             | aAeEfgG       | numbers.
+ *             | (numeric fmt) | For `o', `x', `X', `b' and `B', use
+ *             |               | a minus sign with absolute value for
+ *             |               | negative values.
+ *    ---------+---------------+-----------------------------------------
+ *    -        | all           | Left-justify the result of this conversion.
+ *    ---------+---------------+-----------------------------------------
+ *    0 (zero) | bBdiouxX      | Pad with zeros, not spaces.
+ *             | aAeEfgG       | For `o', `x', `X', `b' and `B', radix-1
+ *             | (numeric fmt) | is used for negative numbers formatted as
+ *             |               | complements.
+ *    ---------+---------------+-----------------------------------------
+ *    *        | all           | Use the next argument as the field width.
+ *             |               | If negative, left-justify the result. If the
+ *             |               | asterisk is followed by a number and a dollar
+ *             |               | sign, use the indicated argument as the width.
+ *
+ *  Examples of flags:
+ *
+ *   # `+' and space flag specifies the sign of non-negative numbers.
+ *   sprintf("%d", 123)  #=> "123"
+ *   sprintf("%+d", 123) #=> "+123"
+ *   sprintf("% d", 123) #=> " 123"
+ *
+ *   # `#' flag for `o' increases number of digits to show `0'.
+ *   # `+' and space flag changes format of negative numbers.
+ *   sprintf("%o", 123)   #=> "173"
+ *   sprintf("%#o", 123)  #=> "0173"
+ *   sprintf("%+o", -123) #=> "-173"
+ *   sprintf("%o", -123)  #=> "..7605"
+ *   sprintf("%#o", -123) #=> "..7605"
+ *
+ *   # `#' flag for `x' add a prefix `0x' for non-zero numbers.
+ *   # `+' and space flag disables complements for negative numbers.
+ *   sprintf("%x", 123)   #=> "7b"
+ *   sprintf("%#x", 123)  #=> "0x7b"
+ *   sprintf("%+x", -123) #=> "-7b"
+ *   sprintf("%x", -123)  #=> "..f85"
+ *   sprintf("%#x", -123) #=> "0x..f85"
+ *   sprintf("%#x", 0)    #=> "0"
+ *
+ *   # `#' for `X' uses the prefix `0X'.
+ *   sprintf("%X", 123)  #=> "7B"
+ *   sprintf("%#X", 123) #=> "0X7B"
+ *
+ *   # `#' flag for `b' add a prefix `0b' for non-zero numbers.
+ *   # `+' and space flag disables complements for negative numbers.
+ *   sprintf("%b", 123)   #=> "1111011"
+ *   sprintf("%#b", 123)  #=> "0b1111011"
+ *   sprintf("%+b", -123) #=> "-1111011"
+ *   sprintf("%b", -123)  #=> "..10000101"
+ *   sprintf("%#b", -123) #=> "0b..10000101"
+ *   sprintf("%#b", 0)    #=> "0"
+ *
+ *   # `#' for `B' uses the prefix `0B'.
+ *   sprintf("%B", 123)  #=> "1111011"
+ *   sprintf("%#B", 123) #=> "0B1111011"
+ *
+ *   # `#' for `e' forces to show the decimal point.
+ *   sprintf("%.0e", 1)  #=> "1e+00"
+ *   sprintf("%#.0e", 1) #=> "1.e+00"
+ *
+ *   # `#' for `f' forces to show the decimal point.
+ *   sprintf("%.0f", 1234)  #=> "1234"
+ *   sprintf("%#.0f", 1234) #=> "1234."
+ *
+ *   # `#' for `g' forces to show the decimal point.
+ *   # It also disables stripping lowest zeros.
+ *   sprintf("%g", 123.4)   #=> "123.4"
+ *   sprintf("%#g", 123.4)  #=> "123.400"
+ *   sprintf("%g", 123456)  #=> "123456"
+ *   sprintf("%#g", 123456) #=> "123456."
+ *
+ *  The field width is an optional integer, followed optionally by a
+ *  period and a precision.  The width specifies the minimum number of
+ *  characters that will be written to the result for this field.
+ *
+ *  Examples of width:
+ *
+ *   # padding is done by spaces,       width=20
+ *   # 0 or radix-1.             <------------------>
+ *   sprintf("%20d", 123)   #=> "                 123"
+ *   sprintf("%+20d", 123)  #=> "                +123"
+ *   sprintf("%020d", 123)  #=> "00000000000000000123"
+ *   sprintf("%+020d", 123) #=> "+0000000000000000123"
+ *   sprintf("% 020d", 123) #=> " 0000000000000000123"
+ *   sprintf("%-20d", 123)  #=> "123                 "
+ *   sprintf("%-+20d", 123) #=> "+123                "
+ *   sprintf("%- 20d", 123) #=> " 123                "
+ *   sprintf("%020x", -123) #=> "..ffffffffffffffff85"
+ *
+ *  For
+ *  numeric fields, the precision controls the number of decimal places
+ *  displayed.  For string fields, the precision determines the maximum
+ *  number of characters to be copied from the string.  (Thus, the format
+ *  sequence <code>%10.10s</code> will always contribute exactly ten
+ *  characters to the result.)
+ *
+ *  Examples of precisions:
+ *
+ *   # precision for `d', 'o', 'x' and 'b' is
+ *   # minimum number of digits               <------>
+ *   sprintf("%20.8d", 123)  #=> "            00000123"
+ *   sprintf("%20.8o", 123)  #=> "            00000173"
+ *   sprintf("%20.8x", 123)  #=> "            0000007b"
+ *   sprintf("%20.8b", 123)  #=> "            01111011"
+ *   sprintf("%20.8d", -123) #=> "           -00000123"
+ *   sprintf("%20.8o", -123) #=> "            ..777605"
+ *   sprintf("%20.8x", -123) #=> "            ..ffff85"
+ *   sprintf("%20.8b", -11)  #=> "            ..110101"
+ *
+ *   # "0x" and "0b" for `#x' and `#b' is not counted for
+ *   # precision but "0" for `#o' is counted.  <------>
+ *   sprintf("%#20.8d", 123)  #=> "            00000123"
+ *   sprintf("%#20.8o", 123)  #=> "            00000173"
+ *   sprintf("%#20.8x", 123)  #=> "          0x0000007b"
+ *   sprintf("%#20.8b", 123)  #=> "          0b01111011"
+ *   sprintf("%#20.8d", -123) #=> "           -00000123"
+ *   sprintf("%#20.8o", -123) #=> "            ..777605"
+ *   sprintf("%#20.8x", -123) #=> "          0x..ffff85"
+ *   sprintf("%#20.8b", -11)  #=> "          0b..110101"
+ *
+ *   # precision for `e' is number of
+ *   # digits after the decimal point           <------>
+ *   sprintf("%20.8e", 1234.56789) #=> "      1.23456789e+03"
+ *
+ *   # precision for `f' is number of
+ *   # digits after the decimal point               <------>
+ *   sprintf("%20.8f", 1234.56789) #=> "       1234.56789000"
+ *
+ *   # precision for `g' is number of
+ *   # significant digits                          <------->
+ *   sprintf("%20.8g", 1234.56789) #=> "           1234.5679"
+ *
+ *   #                                         <------->
+ *   sprintf("%20.8g", 123456789)  #=> "       1.2345679e+08"
+ *
+ *   # precision for `s' is
+ *   # maximum number of characters                    <------>
+ *   sprintf("%20.8s", "string test") #=> "            string t"
+ *
+ *  Examples:
+ *
+ *     sprintf("%d %04x", 123, 123)               #=> "123 007b"
+ *     sprintf("%08b '%4s'", 123, 123)            #=> "01111011 ' 123'"
+ *     sprintf("%1$*2$s %2$d %1$s", "hello", 8)   #=> "   hello 8 hello"
+ *     sprintf("%1$*2$s %2$d", "hello", -8)       #=> "hello    -8"
+ *     sprintf("%+g:% g:%-g", 1.23, 1.23, 1.23)   #=> "+1.23: 1.23:1.23"
+ *     sprintf("%u", -123)                        #=> "-123"
+ *
+ *  For more complex formatting, Ruby supports a reference by name.
+ *  %<name>s style uses format style, but %{name} style doesn't.
+ *
+ *  Exapmles:
+ *    sprintf("%<foo>d : %<bar>f", { :foo => 1, :bar => 2 })
+ *      #=> 1 : 2.000000
+ *    sprintf("%{foo}f", { :foo => 1 })
+ *      # => "1f"
+ */
+
+mrb_value
+mrb_f_sprintf(mrb_state *mrb, mrb_value obj)
+{
+  int argc;
+  mrb_value *argv;
+
+  mrb_get_args(mrb, "*", &argv, &argc);
+
+  if (argc <= 0) {
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "too few arguments");
+    return mrb_nil_value();
+  }
+  else {
+    return mrb_str_format(mrb, argc - 1, argv + 1, argv[0]);
+  }
+}
+
+mrb_value
+mrb_str_format(mrb_state *mrb, int argc, const mrb_value *argv, mrb_value fmt)
+{
+  const char *p, *end;
+  char *buf;
+  long blen, bsiz;
+  mrb_value result;
+  int n;
+  int width, prec, flags = FNONE;
+  int nextarg = 1;
+  int posarg = 0;
+  mrb_value nextvalue;
+  mrb_value tmp;
+  mrb_value str;
+  mrb_value hash = mrb_undef_value();
+
+#define CHECK_FOR_WIDTH(f)                                                  \
+  if ((f) & FWIDTH) {                                                       \
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "width given twice");         \
+  }                                                                         \
+  if ((f) & FPREC0) {                                                       \
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "width after precision");     \
+  }
+#define CHECK_FOR_FLAGS(f)                                                  \
+  if ((f) & FWIDTH) {                                                       \
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "flag after width");          \
+  }                                                                         \
+  if ((f) & FPREC0) {                                                       \
+    mrb_raise(mrb, E_ARGUMENT_ERROR, "flag after precision");      \
+  }
+
+  ++argc;
+  --argv;
+  mrb_string_value(mrb, &fmt);
+  p = RSTRING_PTR(fmt);
+  end = p + RSTRING_LEN(fmt);
+  blen = 0;
+  bsiz = 120;
+  result = mrb_str_buf_new(mrb, bsiz);
+  buf = RSTRING_PTR(result);
+  memset(buf, 0, bsiz);
+
+  for (; p < end; p++) {
+    const char *t;
+    mrb_sym id = 0;
+
+    for (t = p; t < end && *t != '%'; t++) ;
+    PUSH(p, t - p);
+    if (t >= end)
+      goto sprint_exit; /* end of fmt string */
+
+    p = t + 1;    /* skip `%' */
+
+    width = prec = -1;
+    nextvalue = mrb_undef_value();
+
+retry:
+    switch (*p) {
+      default:
+        mrb_raisef(mrb, E_ARGUMENT_ERROR, "malformed format string - %%%c", *p);
+        break;
+
+      case ' ':
+        CHECK_FOR_FLAGS(flags);
+        flags |= FSPACE;
+        p++;
+        goto retry;
+
+      case '#':
+        CHECK_FOR_FLAGS(flags);
+        flags |= FSHARP;
+        p++;
+        goto retry;
+
+      case '+':
+        CHECK_FOR_FLAGS(flags);
+        flags |= FPLUS;
+        p++;
+        goto retry;
+
+      case '-':
+        CHECK_FOR_FLAGS(flags);
+        flags |= FMINUS;
+        p++;
+        goto retry;
+
+      case '0':
+        CHECK_FOR_FLAGS(flags);
+        flags |= FZERO;
+        p++;
+        goto retry;
+
+      case '1': case '2': case '3': case '4':
+      case '5': case '6': case '7': case '8': case '9':
+        n = 0;
+        GETNUM(n, width);
+        if (*p == '$') {
+          if (!mrb_undef_p(nextvalue)) {
+            mrb_raisef(mrb, E_ARGUMENT_ERROR, "value given twice - %d$", n);
+          }
+          nextvalue = GETPOSARG(n);
+          p++;
+          goto retry;
+        }
+        CHECK_FOR_WIDTH(flags);
+        width = n;
+        flags |= FWIDTH;
+        goto retry;
+
+      case '<':
+      case '{': {
+        const char *start = p;
+        char term = (*p == '<') ? '>' : '}';
+        mrb_value symname;
+
+        for (; p < end && *p != term; )
+          p++;
+        if (id) {
+          mrb_raisef(mrb, E_ARGUMENT_ERROR, "name%.*s after <%s>",
+                    (int)(p - start + 1), start, mrb_sym2name(mrb, id));
+        }
+        symname = mrb_str_new(mrb, start + 1, p - start - 1);
+        id = mrb_intern_str(mrb, symname);
+        nextvalue = GETNAMEARG(mrb_symbol_value(id), start, (int)(p - start + 1));
+        if (mrb_undef_p(nextvalue)) {
+          mrb_raisef(mrb, E_KEY_ERROR, "key%.*s not found", (int)(p - start + 1), start);
+        }
+        if (term == '}') goto format_s;
+        p++;
+        goto retry;
+      }
+
+      case '*':
+        CHECK_FOR_WIDTH(flags);
+        flags |= FWIDTH;
+        GETASTER(width);
+        if (width < 0) {
+          flags |= FMINUS;
+          width = -width;
+        }
+        p++;
+        goto retry;
+
+      case '.':
+        if (flags & FPREC0) {
+          mrb_raise(mrb, E_ARGUMENT_ERROR, "precision given twice");
+        }
+        flags |= FPREC|FPREC0;
+
+        prec = 0;
+        p++;
+        if (*p == '*') {
+          GETASTER(prec);
+          if (prec < 0) {  /* ignore negative precision */
+            flags &= ~FPREC;
+          }
+          p++;
+          goto retry;
+        }
+
+        GETNUM(prec, precision);
+        goto retry;
+
+      case '\n':
+      case '\0':
+        p--;
+
+      case '%':
+        if (flags != FNONE) {
+          mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid format character - %");
+        }
+        PUSH("%", 1);
+        break;
+
+      case 'c': {
+        mrb_value val = GETARG();
+        mrb_value tmp;
+        unsigned int c;
+
+        tmp = mrb_check_string_type(mrb, val);
+        if (!mrb_nil_p(tmp)) {
+          if (RSTRING_LEN(tmp) != 1 ) {
+            mrb_raise(mrb, E_ARGUMENT_ERROR, "%c requires a character");
+          }
+          c = RSTRING_PTR(tmp)[0];
+          n = 1;
+        }
+        else {
+          c = mrb_fixnum(val);
+          n = 1;
+        }
+        if (n <= 0) {
+          mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid character");
+        }
+        if (!(flags & FWIDTH)) {
+          CHECK(n);
+          buf[blen] = c;
+          blen += n;
+        }
+        else if ((flags & FMINUS)) {
+          CHECK(n);
+          buf[blen] = c;
+          blen += n;
+          FILL(' ', width-1);
+        }
+        else {
+          FILL(' ', width-1);
+          CHECK(n);
+          buf[blen] = c;
+          blen += n;
+        }
+      }
+      break;
+
+      case 's':
+      case 'p':
+  format_s:
+      {
+        mrb_value arg = GETARG();
+        long len, slen;
+
+        if (*p == 'p') arg = mrb_inspect(mrb, arg);
+        str = mrb_obj_as_string(mrb, arg);
+        len = RSTRING_LEN(str);
+        RSTRING_LEN(result) = blen;
+        if (flags&(FPREC|FWIDTH)) {
+          slen = RSTRING_LEN(str);
+          if (slen < 0) {
+            mrb_raise(mrb, E_ARGUMENT_ERROR, "invalid mbstring sequence");
+          }
+          if ((flags&FPREC) && (prec < slen)) {
+            char *p = RSTRING_PTR(str) + prec;
+            slen = prec;
+            len = p - RSTRING_PTR(str);
+          }
+          /* need to adjust multi-byte string pos */
+          if ((flags&FWIDTH) && (width > slen)) {
+            width -= (int)slen;
+            if (!(flags&FMINUS)) {
+              CHECK(width);
+              while (width--) {
+                buf[blen++] = ' ';
+              }
+            }
+            CHECK(len);
+            memcpy(&buf[blen], RSTRING_PTR(str), len);
+            blen += len;
+            if (flags&FMINUS) {
+              CHECK(width);
+              while (width--) {
+                buf[blen++] = ' ';
+              }
+            }
+            break;
+          }
+        }
+        PUSH(RSTRING_PTR(str), len);
+      }
+      break;
+
+      case 'd':
+      case 'i':
+      case 'o':
+      case 'x':
+      case 'X':
+      case 'b':
+      case 'B':
+      case 'u': {
+        mrb_value val = GETARG();
+        char fbuf[32], nbuf[64], *s;
+        const char *prefix = 0;
+        int sign = 0, dots = 0;
+        char sc = 0;
+        long v = 0, org_v = 0;
+        int base;
+        int len;
+
+        switch (*p) {
+          case 'd':
+          case 'i':
+          case 'u':
+            sign = 1; break;
+          case 'o':
+          case 'x':
+          case 'X':
+          case 'b':
+          case 'B':
+            if (flags&(FPLUS|FSPACE)) sign = 1;
+            break;
+          default:
+            break;
+        }
+        if (flags & FSHARP) {
+          switch (*p) {
+            case 'o': prefix = "0"; break;
+            case 'x': prefix = "0x"; break;
+            case 'X': prefix = "0X"; break;
+            case 'b': prefix = "0b"; break;
+            case 'B': prefix = "0B"; break;
+            default: break;
+          }
+        }
+
+  bin_retry:
+        switch (mrb_type(val)) {
+          case MRB_TT_FLOAT:
+            if (FIXABLE(mrb_float(val))) {
+              val = mrb_fixnum_value((mrb_int)mrb_float(val));
+              goto bin_retry;
+            }
+            val = mrb_flt2big(mrb, mrb_float(val));
+            if (mrb_fixnum_p(val)) goto bin_retry;
+            break;
+          case MRB_TT_STRING:
+            val = mrb_str_to_inum(mrb, val, 0, TRUE);
+            goto bin_retry;
+          case MRB_TT_FIXNUM:
+            v = (long)mrb_fixnum(val);
+            break;
+          default:
+            val = mrb_Integer(mrb, val);
+            goto bin_retry;
+        }
+
+        switch (*p) {
+          case 'o':
+            base = 8; break;
+          case 'x':
+          case 'X':
+            base = 16; break;
+          case 'b':
+          case 'B':
+            base = 2; break;
+          case 'u':
+          case 'd':
+          case 'i':
+          default:
+            base = 10; break;
+        }
+
+        if (base == 2) {
+          org_v = v;
+          if ( v < 0 && !sign ) {
+            val = mrb_fix2binstr(mrb, mrb_fixnum_value(v), base);
+            dots = 1;
+          }
+          else {
+            val = mrb_fix2str(mrb, mrb_fixnum_value(v), base);
+          }
+          v = mrb_fixnum(mrb_str_to_inum(mrb, val, 10, 0/*Qfalse*/));
+        }
+        if (sign) {
+          char c = *p;
+          if (c == 'i') c = 'd'; /* %d and %i are identical */
+          if (base == 2) c = 'd';
+          if (v < 0) {
+            v = -v;
+            sc = '-';
+            width--;
+          }
+          else if (flags & FPLUS) {
+            sc = '+';
+            width--;
+          }
+          else if (flags & FSPACE) {
+            sc = ' ';
+            width--;
+          }
+          snprintf(fbuf, sizeof(fbuf), "%%l%c", c);
+          snprintf(nbuf, sizeof(nbuf), fbuf, v);
+          s = nbuf;
+        }
+        else {
+          char c = *p;
+          if (c == 'X') c = 'x';
+          if (base == 2) c = 'd';
+          s = nbuf;
+          if (v < 0) {
+            dots = 1;
+          }
+          snprintf(fbuf, sizeof(fbuf), "%%l%c", c);
+          snprintf(++s, sizeof(nbuf) - 1, fbuf, v);
+          if (v < 0) {
+            char d;
+
+            s = remove_sign_bits(s, base);
+            switch (base) {
+              case 16: d = 'f'; break;
+              case 8:  d = '7'; break;
+              case 2:  d = '1'; break;
+              default: d = 0; break;
+            }
+
+            if (d && *s != d) {
+              *--s = d;
+            }
+          }
+        }
+        len = (int)strlen(s);
+
+        if (dots) {
+          prec -= 2;
+          width -= 2;
+        }
+
+        if (*p == 'X') {
+          char *pp = s;
+          int c;
+          while ((c = (int)(unsigned char)*pp) != 0) {
+            *pp = toupper(c);
+            pp++;
+          }
+        }
+
+        if (prefix && !prefix[1]) { /* octal */
+          if (dots) {
+            prefix = 0;
+          }
+          else if (len == 1 && *s == '0') {
+            len = 0;
+            if (flags & FPREC) prec--;
+          }
+          else if ((flags & FPREC) && (prec > len)) {
+            prefix = 0;
+          }
+        }
+        else if (len == 1 && *s == '0') {
+          prefix = 0;
+        }
+
+        if (prefix) {
+          width -= (int)strlen(prefix);
+        }
+
+        if ((flags & (FZERO|FMINUS|FPREC)) == FZERO) {
+          prec = width;
+          width = 0;
+        }
+        else {
+          if (prec < len) {
+            if (!prefix && prec == 0 && len == 1 && *s == '0') len = 0;
+            prec = len;
+          }
+          width -= prec;
+        }
+
+        if (!(flags&FMINUS)) {
+          CHECK(width);
+          while (width-- > 0) {
+            buf[blen++] = ' ';
+          }
+        }
+
+        if (sc) PUSH(&sc, 1);
+
+        if (prefix) {
+          int plen = (int)strlen(prefix);
+          PUSH(prefix, plen);
+        }
+        CHECK(prec - len);
+        if (dots) PUSH("..", 2);
+
+        if (v < 0 || (base == 2 && org_v < 0)) {
+          char c = sign_bits(base, p);
+          while (len < prec--) {
+            buf[blen++] = c;
+          }
+        }
+        else if ((flags & (FMINUS|FPREC)) != FMINUS) {
+          char c = '0';
+          while (len < prec--) {
+            buf[blen++] = c;
+          }
+        }
+
+        PUSH(s, len);
+        CHECK(width);
+        while (width-- > 0) {
+          buf[blen++] = ' ';
+        }
+      }
+      break;
+
+      case 'f':
+      case 'g':
+      case 'G':
+      case 'e':
+      case 'E':
+      case 'a':
+      case 'A': {
+        mrb_value val = GETARG();
+        double fval;
+        int i, need = 6;
+        char fbuf[32];
+
+        fval = mrb_float(mrb_Float(mrb, val));
+        if (isnan(fval) || isinf(fval)) {
+          const char *expr;
+          const int elen = 3;
+
+          if (isnan(fval)) {
+            expr = "NaN";
+          }
+          else {
+            expr = "Inf";
+          }
+          need = elen;
+          if ((!isnan(fval) && fval < 0.0) || (flags & FPLUS))
+            need++;
+          if ((flags & FWIDTH) && need < width)
+            need = width;
+
+          CHECK(need + 1);
+          n = snprintf(&buf[blen], need + 1, "%*s", need, "");
+          if (flags & FMINUS) {
+            if (!isnan(fval) && fval < 0.0)
+              buf[blen++] = '-';
+            else if (flags & FPLUS)
+              buf[blen++] = '+';
+            else if (flags & FSPACE)
+              blen++;
+            memcpy(&buf[blen], expr, elen);
+          }
+          else {
+            if (!isnan(fval) && fval < 0.0)
+              buf[blen + need - elen - 1] = '-';
+            else if (flags & FPLUS)
+              buf[blen + need - elen - 1] = '+';
+            else if ((flags & FSPACE) && need > width)
+              blen++;
+            memcpy(&buf[blen + need - elen], expr, elen);
+          }
+          blen += strlen(&buf[blen]);
+          break;
+        }
+
+        fmt_setup(fbuf, sizeof(fbuf), *p, flags, width, prec);
+        need = 0;
+        if (*p != 'e' && *p != 'E') {
+          i = INT_MIN;
+          frexp(fval, &i);
+          if (i > 0)
+            need = BIT_DIGITS(i);
+        }
+        need += (flags&FPREC) ? prec : 6;
+        if ((flags&FWIDTH) && need < width)
+          need = width;
+        need += 20;
+
+        CHECK(need);
+        n = snprintf(&buf[blen], need, fbuf, fval);
+        blen += n;
+      }
+      break;
+    }
+    flags = FNONE;
+  }
+
+  sprint_exit:
+#if 0
+  /* XXX - We cannot validate the number of arguments if (digit)$ style used.
+   */
+  if (posarg >= 0 && nextarg < argc) {
+    const char *mesg = "too many arguments for format string";
+    if (mrb_test(ruby_debug)) mrb_raise(mrb, E_ARGUMENT_ERROR, mesg);
+    if (mrb_test(ruby_verbose)) mrb_warn("%s", mesg);
+  }
+#endif
+  mrb_str_resize(mrb, result, blen);
+
+  return result;
+}
+
+static void
+fmt_setup(char *buf, size_t size, int c, int flags, int width, int prec)
+{
+  char *end = buf + size;
+  int n;
+
+  *buf++ = '%';
+  if (flags & FSHARP) *buf++ = '#';
+  if (flags & FPLUS)  *buf++ = '+';
+  if (flags & FMINUS) *buf++ = '-';
+  if (flags & FZERO)  *buf++ = '0';
+  if (flags & FSPACE) *buf++ = ' ';
+
+  if (flags & FWIDTH) {
+    n = snprintf(buf, end - buf, "%d", width);
+    buf += n;
+  }
+
+  if (flags & FPREC) {
+    n = snprintf(buf, end - buf, ".%d", prec);
+    buf += n;
+  }
+
+  *buf++ = c;
+  *buf = '\0';
+}
+
+#endif	/* ENABLE_SPRINTF */