[v2,04/14] locale: Implement struct grouping_iterator

  The iterator allows grouping while scanning forward through
the digits.  This enables emitting digits as they are processed.
---
 stdio-common/Makefile                |   9 +-
 stdio-common/grouping_iterator.c     | 125 +++++++++++++
 stdio-common/grouping_iterator.h     |  65 +++++++
 stdio-common/tst-grouping_iterator.c | 262 +++++++++++++++++++++++++++
 4 files changed, 460 insertions(+), 1 deletion(-)
 create mode 100644 stdio-common/grouping_iterator.c
 create mode 100644 stdio-common/grouping_iterator.h
 create mode 100644 stdio-common/tst-grouping_iterator.c
  

On 23/05/2022 11:07, Florian Weimer via Libc-alpha wrote:
> The iterator allows grouping while scanning forward through
> the digits.  This enables emitting digits as they are processed.

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
>  stdio-common/Makefile                |   9 +-
>  stdio-common/grouping_iterator.c     | 125 +++++++++++++
>  stdio-common/grouping_iterator.h     |  65 +++++++
>  stdio-common/tst-grouping_iterator.c | 262 +++++++++++++++++++++++++++
>  4 files changed, 460 insertions(+), 1 deletion(-)
>  create mode 100644 stdio-common/grouping_iterator.c
>  create mode 100644 stdio-common/grouping_iterator.h
>  create mode 100644 stdio-common/tst-grouping_iterator.c
> 
> diff --git a/stdio-common/Makefile b/stdio-common/Makefile
> index b1e9144de0..da3a3bc0c9 100644
> --- a/stdio-common/Makefile
> +++ b/stdio-common/Makefile
> @@ -39,6 +39,7 @@ routines := \
>    gentempfd \
>    getline \
>    getw \
> +  grouping_iterator \
>    iovfscanf \
>    isoc99_fscanf \
>    isoc99_scanf \
> @@ -221,6 +222,10 @@ generated += \
>    siglist-aux.S \
>    # generated
>  
> +tests-internal = \
> +  tst-grouping_iterator \
> +  # tests-internal
> +
>  test-srcs = tst-unbputc tst-printf tst-printfsz-islongdouble
>  
>  ifeq ($(run-built-tests),yes)
> @@ -288,13 +293,15 @@ LOCALES := \
>    hi_IN.UTF-8 \
>    ja_JP.EUC-JP \
>    ps_AF.UTF-8 \
> -  # LOCALES
> +  tg_TJ.UTF-8 \
> + # LOCALES
>  include ../gen-locales.mk
>  
>  $(objpfx)bug14.out: $(gen-locales)
>  $(objpfx)scanf13.out: $(gen-locales)
>  $(objpfx)test-vfprintf.out: $(gen-locales)
>  $(objpfx)tst-grouping.out: $(gen-locales)
> +$(objpfx)tst-grouping_iterator.out: $(gen-locales)
>  $(objpfx)tst-sprintf.out: $(gen-locales)
>  $(objpfx)tst-sscanf.out: $(gen-locales)
>  $(objpfx)tst-swprintf.out: $(gen-locales)

Ok.

> diff --git a/stdio-common/grouping_iterator.c b/stdio-common/grouping_iterator.c
> new file mode 100644
> index 0000000000..cc169e2b09
> --- /dev/null
> +++ b/stdio-common/grouping_iterator.c
> @@ -0,0 +1,125 @@
> +/* Iterator for inserting thousands separators into numbers.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#include <grouping_iterator.h>
> +
> +#include <assert.h>
> +#include <limits.h>
> +#include <locale/localeinfo.h>
> +#include <stdint.h>
> +#include <string.h>
> +
> +/* Initializes *IT with no grouping information for a string of length
> +   DIGITS, and return false to indicate no grouping.  */
> +bool
> +__grouping_iterator_init_none (struct grouping_iterator *it, size_t digits)
> +{
> +  memset (it, 0, sizeof (*it));
> +  it->remaining_in_current_group = digits;
> +  it->remaining = digits;
> +  return false;
> +}

Ok, I would guess compiler will optimize the memset away.

> +
> +static bool
> +grouping_iterator_setup (struct grouping_iterator *it, size_t digits,
> +                         const char *grouping)
> +{
> +  /* We treat all negative values like CHAR_MAX.  */
> +
> +  if (*grouping == CHAR_MAX || *grouping <= 0)
> +    /* No grouping should be done.  */
> +    return __grouping_iterator_init_none (it, digits);
> +
> +  size_t remaining_to_group = digits;
> +  size_t non_repeating_groups = 0;
> +  size_t groups = 0;
> +  while (true)
> +    {
> +      non_repeating_groups += *grouping;
> +      if (remaining_to_group <= (unsigned int) *grouping)
> +        break;
> +
> +      ++groups;
> +      remaining_to_group -= *grouping++;
> +
> +      if (*grouping == CHAR_MAX
> +#if CHAR_MIN < 0
> +          || *grouping < 0
> +#endif
> +          )
> +          /* No more grouping should be done.  */
> +        break;
> +      else if (*grouping == 0)
> +        {
> +          /* Same grouping repeats.  */
> +          --grouping;
> +          non_repeating_groups -= *grouping; /* Over-counted.  */
> +          size_t repeats = (remaining_to_group - 1) / *grouping;
> +          groups += repeats;
> +          remaining_to_group -= repeats * *grouping;
> +          break;
> +        }
> +    }
> +
> +  it->remaining_in_current_group = remaining_to_group;
> +  it->remaining = digits;
> +  it->groupings = grouping;
> +  it->non_repeating_groups = non_repeating_groups;
> +  it->separators = groups;
> +  return it->separators > 0;
> +}
> +
> +/* Returns the appropriate grouping item in LOC depending on CATEGORY
> +   (which must be LC_MONETARY or LC_NUMERIC).  */
> +static const char *
> +get_grouping (int category, locale_t loc)
> +{
> +  return _nl_lookup (loc, category,
> +                     category == LC_MONETARY ? MON_GROUPING : GROUPING);
> +}
> +
> +
> +bool
> +__grouping_iterator_init (struct grouping_iterator *it,
> +                          int category, locale_t loc, size_t digits)
> +{
> +  if (digits <= 1)
> +    return __grouping_iterator_init_none (it, digits);
> +  else
> +    return grouping_iterator_setup (it, digits, get_grouping (category, loc));
> +}
> +
> +bool
> +__grouping_iterator_next (struct grouping_iterator *it)
> +{
> +  assert (it->remaining > 0);
> +  --it->remaining;
> +
> +  if (it->remaining_in_current_group > 0)
> +    {
> +      --it->remaining_in_current_group;
> +      return false;
> +    }
> +
> +  /* If we are in the non-repeating part, switch group.  */
> +  if (it->remaining < it->non_repeating_groups)
> +    --it->groupings;
> +
> +  it->remaining_in_current_group = *it->groupings - 1;
> +  return true;
> +}

Ok.

> diff --git a/stdio-common/grouping_iterator.h b/stdio-common/grouping_iterator.h
> new file mode 100644
> index 0000000000..ca41a7fdc1
> --- /dev/null
> +++ b/stdio-common/grouping_iterator.h
> @@ -0,0 +1,65 @@
> +/* Iterator for grouping a number while scanning it forward.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +#ifndef GROUPING_ITERATOR_H
> +#define GROUPING_ITERATOR_H
> +
> +#include <locale.h>
> +#include <stdbool.h>
> +#include <stddef.h>
> +
> +struct grouping_iterator
> +{
> +  /* Number of characters in the current group.  If this reaches zero,
> +     a thousands separator needs to be emittted.  */
> +  size_t remaining_in_current_group;
> +
> +  /* Number of characters remaining in the number.  This is used to
> +     detect the start of the non-repeating groups.  */
> +  size_t remaining;
> +
> +  /* Points to the current grouping descriptor.  */
> +  const char *groupings;
> +
> +  /* Total number of characters in the non-repeating groups.  */
> +  size_t non_repeating_groups;
> +
> +  /* Number of separators that will be inserted if the whole number is
> +     processed.  (Does not change during iteration.)  */
> +  size_t separators;
> +};
> +
> +struct __locale_data;
> +
> +/* Initializes *IT with the data from LOCDATA (which must be for
> +   LC_MONETARY or LC_NUMERIC).  DIGITS is the length of the number.
> +   Returns true if grouping is active, false if not.  */
> +bool __grouping_iterator_init (struct grouping_iterator *it,
> +                               int category, locale_t loc,
> +                               size_t digits) attribute_hidden;
> +
> +/* Initializes *IT with no grouping information for a string of length
> +   DIGITS, and return false to indicate no grouping.  */
> +bool __grouping_iterator_init_none (struct grouping_iterator *it, size_t digits)
> +  attribute_hidden;
> +
> +/* Advances to the next character and returns true if a thousands
> +   separator should be inserted before emitting it.  */
> +bool __grouping_iterator_next (struct grouping_iterator *it);
> +
> +#endif /* GROUPING_ITERATOR_H */

Ok.

> diff --git a/stdio-common/tst-grouping_iterator.c b/stdio-common/tst-grouping_iterator.c
> new file mode 100644
> index 0000000000..97d8f40628
> --- /dev/null
> +++ b/stdio-common/tst-grouping_iterator.c
> @@ -0,0 +1,262 @@
> +/* Test for struct grouping_iterator.
> +   Copyright (C) 2022 Free Software Foundation, Inc.
> +   This file is part of the GNU C Library.
> +
> +   The GNU C Library is free software; you can redistribute it and/or
> +   modify it under the terms of the GNU Lesser General Public
> +   License as published by the Free Software Foundation; either
> +   version 2.1 of the License, or (at your option) any later version.
> +
> +   The GNU C Library is distributed in the hope that it will be useful,
> +   but WITHOUT ANY WARRANTY; without even the implied warranty of
> +   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> +   Lesser General Public License for more details.
> +
> +   You should have received a copy of the GNU Lesser General Public
> +   License along with the GNU C Library; if not, see
> +   <https://www.gnu.org/licenses/>.  */
> +
> +/* Rebuild the fail to access internal-only functions.  */
> +#include <grouping_iterator.c>
> +
> +#include <stdio.h>
> +#include <support/check.h>
> +#include <support/support.h>
> +#include <support/test-driver.h>
> +
> +static void
> +check (int lineno, const char *groupings,
> +       const char *input, const char *expected)
> +{
> +  if (test_verbose)
> +    {
> +      printf ("info: %s:%d: \"%s\" via \"", __FILE__, lineno, input);
> +      for (const char *p = groupings; *p != 0; ++p)
> +        printf ("\\%o", *p & 0xff);
> +      printf ("\" to \"%s\"\n", expected);
> +    }
> +
> +  size_t initial_group = strchrnul (expected, '\'') - expected;
> +  size_t separators = 0;
> +  for (const char *p = expected; *p != '\0'; ++p)
> +    separators += *p == '\'';
> +
> +  size_t digits = strlen (input);
> +  char *out = xmalloc (2 * digits + 1);
> +
> +  struct grouping_iterator it;
> +  TEST_COMPARE (grouping_iterator_setup (&it, digits, groupings),
> +                strchr (expected, '\'') != NULL);
> +  TEST_COMPARE (it.remaining, digits);
> +  TEST_COMPARE (it.remaining_in_current_group, initial_group);
> +  TEST_COMPARE (it.separators, separators);
> +
> +  char *p = out;
> +  while (*input != '\0')
> +    {
> +      if (__grouping_iterator_next (&it))
> +        *p++ = '\'';
> +      TEST_COMPARE (it.separators, separators);
> +      *p++ = *input++;
> +    }
> +  *p++ = '\0';
> +
> +  TEST_COMPARE (it.remaining, 0);
> +  TEST_COMPARE (it.remaining_in_current_group, 0);
> +
> +  TEST_COMPARE_STRING (out, expected);
> +
> +  free (out);
> +}
> +
> +static int
> +do_test (void)
> +{
> +  check (__LINE__, "", "1", "1");
> +  check (__LINE__, "", "12", "12");
> +  check (__LINE__, "", "123", "123");
> +  check (__LINE__, "", "1234", "1234");
> +
> +  check (__LINE__, "\3", "1", "1");
> +  check (__LINE__, "\3", "12", "12");
> +  check (__LINE__, "\3", "123", "123");
> +  check (__LINE__, "\3", "1234", "1'234");
> +  check (__LINE__, "\3", "12345", "12'345");
> +  check (__LINE__, "\3", "123456", "123'456");
> +  check (__LINE__, "\3", "1234567", "1'234'567");
> +  check (__LINE__, "\3", "12345678", "12'345'678");
> +  check (__LINE__, "\3", "123456789", "123'456'789");
> +  check (__LINE__, "\3", "1234567890", "1'234'567'890");
> +
> +  check (__LINE__, "\2\3", "1", "1");
> +  check (__LINE__, "\2\3", "12", "12");
> +  check (__LINE__, "\2\3", "123", "1'23");
> +  check (__LINE__, "\2\3", "1234", "12'34");
> +  check (__LINE__, "\2\3", "12345", "123'45");
> +  check (__LINE__, "\2\3", "123456", "1'234'56");
> +  check (__LINE__, "\2\3", "1234567", "12'345'67");
> +  check (__LINE__, "\2\3", "12345678", "123'456'78");
> +  check (__LINE__, "\2\3", "123456789", "1'234'567'89");
> +  check (__LINE__, "\2\3", "1234567890", "12'345'678'90");
> +
> +  check (__LINE__, "\3\2", "1", "1");
> +  check (__LINE__, "\3\2", "12", "12");
> +  check (__LINE__, "\3\2", "123", "123");
> +  check (__LINE__, "\3\2", "1234", "1'234");
> +  check (__LINE__, "\3\2", "12345", "12'345");
> +  check (__LINE__, "\3\2", "123456", "1'23'456");
> +  check (__LINE__, "\3\2", "1234567", "12'34'567");
> +  check (__LINE__, "\3\2", "12345678", "1'23'45'678");
> +  check (__LINE__, "\3\2", "123456789", "12'34'56'789");
> +  check (__LINE__, "\3\2", "1234567890", "1'23'45'67'890");
> +
> +  check (__LINE__, "\3\2\1", "1", "1");
> +  check (__LINE__, "\3\2\1", "12", "12");
> +  check (__LINE__, "\3\2\1", "123", "123");
> +  check (__LINE__, "\3\2\1", "1234", "1'234");
> +  check (__LINE__, "\3\2\1", "12345", "12'345");
> +  check (__LINE__, "\3\2\1", "123456", "1'23'456");
> +  check (__LINE__, "\3\2\1", "1234567", "1'2'34'567");
> +  check (__LINE__, "\3\2\1", "12345678", "1'2'3'45'678");
> +  check (__LINE__, "\3\2\1", "123456789", "1'2'3'4'56'789");
> +  check (__LINE__, "\3\2\1", "1234567890", "1'2'3'4'5'67'890");
> +
> +  check (__LINE__, "\2\3\1", "1", "1");
> +  check (__LINE__, "\2\3\1", "12", "12");
> +  check (__LINE__, "\2\3\1", "123", "1'23");
> +  check (__LINE__, "\2\3\1", "1234", "12'34");
> +  check (__LINE__, "\2\3\1", "12345", "123'45");
> +  check (__LINE__, "\2\3\1", "123456", "1'234'56");
> +  check (__LINE__, "\2\3\1", "1234567", "1'2'345'67");
> +  check (__LINE__, "\2\3\1", "12345678", "1'2'3'456'78");
> +  check (__LINE__, "\2\3\1", "123456789", "1'2'3'4'567'89");
> +  check (__LINE__, "\2\3\1", "1234567890", "1'2'3'4'5'678'90");
> +
> +  /* No repeats.  */
> +  check (__LINE__, "\3\377", "1", "1");
> +  check (__LINE__, "\3\377", "12", "12");
> +  check (__LINE__, "\3\377", "123", "123");
> +  check (__LINE__, "\3\377", "1234", "1'234");
> +  check (__LINE__, "\3\377", "12345", "12'345");
> +  check (__LINE__, "\3\377", "123456", "123'456");
> +  check (__LINE__, "\3\377", "1234567", "1234'567");
> +  check (__LINE__, "\3\377", "12345678", "12345'678");
> +
> +  check (__LINE__, "\2\3\377", "1", "1");
> +  check (__LINE__, "\2\3\377", "12", "12");
> +  check (__LINE__, "\2\3\377", "123", "1'23");
> +  check (__LINE__, "\2\3\377", "1234", "12'34");
> +  check (__LINE__, "\2\3\377", "12345", "123'45");
> +  check (__LINE__, "\2\3\377", "123456", "1'234'56");
> +  check (__LINE__, "\2\3\377", "1234567", "12'345'67");
> +  check (__LINE__, "\2\3\377", "12345678", "123'456'78");
> +  check (__LINE__, "\2\3\377", "123456789", "1234'567'89");
> +  check (__LINE__, "\2\3\377", "1234567890", "12345'678'90");
> +
> +  check (__LINE__, "\3\2\377", "1", "1");
> +  check (__LINE__, "\3\2\377", "12", "12");
> +  check (__LINE__, "\3\2\377", "123", "123");
> +  check (__LINE__, "\3\2\377", "1234", "1'234");
> +  check (__LINE__, "\3\2\377", "12345", "12'345");
> +  check (__LINE__, "\3\2\377", "123456", "1'23'456");
> +  check (__LINE__, "\3\2\377", "1234567", "12'34'567");
> +  check (__LINE__, "\3\2\377", "12345678", "123'45'678");
> +  check (__LINE__, "\3\2\377", "123456789", "1234'56'789");
> +  check (__LINE__, "\3\2\377", "1234567890", "12345'67'890");
> +
> +  /* Locale-based tests.  */
> +
> +  locale_t loc;
> +  struct lc_ctype_data *ctype;
> +  struct grouping_iterator it;
> +
> +  loc = newlocale (LC_ALL_MASK, "de_DE.UTF-8", 0);
> +  TEST_VERIFY_EXIT (loc != 0);
> +  ctype = loc->__locales[LC_CTYPE]->private;
> +  TEST_VERIFY (!ctype->outdigit_translation_needed);
> +  for (int i = 0; i <= 9; ++i)
> +    TEST_COMPARE (ctype->outdigit_bytes[i], 1);
> +  TEST_COMPARE (ctype->outdigit_bytes_all_equal, 1);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_NUMERIC, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 3); /* Locale duplicates 3.  */
> +  TEST_COMPARE (it.separators, 2);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_MONETARY, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 3); /* Locale duplicates 3.  */
> +  TEST_COMPARE (it.separators, 2);
> +  freelocale (loc);
> +
> +  loc = newlocale (LC_ALL_MASK, "tg_TJ.UTF-8", 0);
> +  TEST_VERIFY_EXIT (loc != 0);
> +  ctype = loc->__locales[LC_CTYPE]->private;
> +  TEST_VERIFY (!ctype->outdigit_translation_needed);
> +  for (int i = 0; i <= 9; ++i)
> +    TEST_COMPARE (ctype->outdigit_bytes[i], 1);
> +  TEST_COMPARE (ctype->outdigit_bytes_all_equal, 1);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_NUMERIC, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 3); /* Locale duplicates 3.  */
> +  TEST_COMPARE (it.separators, 2);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_MONETARY, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 3); /* Locale duplicates 3.  */
> +  TEST_COMPARE (it.separators, 2);
> +  freelocale (loc);
> +
> +  loc = newlocale (LC_ALL_MASK, "hi_IN.UTF-8", 0);
> +  TEST_VERIFY_EXIT (loc != 0);
> +  ctype = loc->__locales[LC_CTYPE]->private;
> +  TEST_VERIFY (ctype->outdigit_translation_needed);
> +  for (int i = 0; i <= 9; ++i)
> +    /* Locale uses Devanagari digits.  */
> +    TEST_COMPARE (ctype->outdigit_bytes[i], 3);
> +  TEST_COMPARE (ctype->outdigit_bytes_all_equal, 3);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_NUMERIC, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 0);
> +  TEST_COMPARE (it.separators, 2);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_MONETARY, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 1);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 2);
> +  TEST_COMPARE (it.non_repeating_groups, 3);
> +  TEST_COMPARE (it.separators, 3);
> +  freelocale (loc);
> +
> +  loc = newlocale (LC_ALL_MASK, "ps_AF.UTF-8", 0);
> +  TEST_VERIFY_EXIT (loc != 0);
> +  ctype = loc->__locales[LC_CTYPE]->private;
> +  TEST_VERIFY (ctype->outdigit_translation_needed);
> +  for (int i = 0; i <= 9; ++i)
> +    /* Locale uses non-ASCII digits.  */
> +    TEST_COMPARE (ctype->outdigit_bytes[i], 2);
> +  TEST_COMPARE (ctype->outdigit_bytes_all_equal, 2);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_NUMERIC, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 0);
> +  TEST_COMPARE (it.separators, 2);
> +  TEST_COMPARE (__grouping_iterator_init (&it, LC_MONETARY, loc, 8), true);
> +  TEST_COMPARE (it.remaining_in_current_group, 2);
> +  TEST_COMPARE (it.remaining, 8);
> +  TEST_COMPARE (*it.groupings, 3);
> +  TEST_COMPARE (it.non_repeating_groups, 0);
> +  TEST_COMPARE (it.separators, 2);
> +  freelocale (loc);
> +
> +  return 0;
> +}
> +
> +#include <support/test-driver.c>

Ok.
  

On Mai 23 2022, Florian Weimer via Libc-alpha wrote:

> +struct grouping_iterator
> +{
> +  /* Number of characters in the current group.  If this reaches zero,
> +     a thousands separator needs to be emittted.  */
> +  size_t remaining_in_current_group;
> +
> +  /* Number of characters remaining in the number.  This is used to
> +     detect the start of the non-repeating groups.  */
> +  size_t remaining;
> +
> +  /* Points to the current grouping descriptor.  */
> +  const char *groupings;
> +
> +  /* Total number of characters in the non-repeating groups.  */
> +  size_t non_repeating_groups;
> +
> +  /* Number of separators that will be inserted if the whole number is
> +     processed.  (Does not change during iteration.)  */
> +  size_t separators;

Does that really need the full range of size_t?  I think unsigned int
should be enough.

> +};
> +
> +struct __locale_data;
> +
> +/* Initializes *IT with the data from LOCDATA (which must be for
> +   LC_MONETARY or LC_NUMERIC).  DIGITS is the length of the number.
> +   Returns true if grouping is active, false if not.  */
> +bool __grouping_iterator_init (struct grouping_iterator *it,
> +                               int category, locale_t loc,
> +                               size_t digits) attribute_hidden;
> +
> +/* Initializes *IT with no grouping information for a string of length
> +   DIGITS, and return false to indicate no grouping.  */
> +bool __grouping_iterator_init_none (struct grouping_iterator *it, size_t digits)
> +  attribute_hidden;

Similarily, the digits argument can be unsigned int (format string
lengths are limited by int anyway).
  

* Andreas Schwab:

> On Mai 23 2022, Florian Weimer via Libc-alpha wrote:
>
>> +struct grouping_iterator
>> +{
>> +  /* Number of characters in the current group.  If this reaches zero,
>> +     a thousands separator needs to be emittted.  */
>> +  size_t remaining_in_current_group;
>> +
>> +  /* Number of characters remaining in the number.  This is used to
>> +     detect the start of the non-repeating groups.  */
>> +  size_t remaining;
>> +
>> +  /* Points to the current grouping descriptor.  */
>> +  const char *groupings;
>> +
>> +  /* Total number of characters in the non-repeating groups.  */
>> +  size_t non_repeating_groups;
>> +
>> +  /* Number of separators that will be inserted if the whole number is
>> +     processed.  (Does not change during iteration.)  */
>> +  size_t separators;
>
> Does that really need the full range of size_t?  I think unsigned int
> should be enough.
>
>> +};
>> +
>> +struct __locale_data;
>> +
>> +/* Initializes *IT with the data from LOCDATA (which must be for
>> +   LC_MONETARY or LC_NUMERIC).  DIGITS is the length of the number.
>> +   Returns true if grouping is active, false if not.  */
>> +bool __grouping_iterator_init (struct grouping_iterator *it,
>> +                               int category, locale_t loc,
>> +                               size_t digits) attribute_hidden;
>> +
>> +/* Initializes *IT with no grouping information for a string of length
>> +   DIGITS, and return false to indicate no grouping.  */
>> +bool __grouping_iterator_init_none (struct grouping_iterator *it, size_t digits)
>> +  attribute_hidden;
>
> Similarily, the digits argument can be unsigned int (format string
> lengths are limited by int anyway).

Yes, switching to unsigned int should work.  I will make the change and
re-test.

Thanks,
Florian