1 files changed, 94 insertions, 0 deletions
diff --git a/subprojects/exess/src/ulong.c b/subprojects/exess/src/ulong.c
new file mode 100644
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+++ b/subprojects/exess/src/ulong.c
@@ -0,0 +1,94 @@
+/*
+  Copyright 2019-2021 David Robillard <d@drobilla.net>
+
+  Permission to use, copy, modify, and/or distribute this software for any
+  purpose with or without fee is hereby granted, provided that the above
+  copyright notice and this permission notice appear in all copies.
+
+  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "exess/exess.h"
+#include "int_math.h"
+#include "read_utils.h"
+#include "string_utils.h"
+#include "write_utils.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+
+ExessResult
+exess_read_ulong(uint64_t* const out, const char* const str)
+{
+  *out = 0;
+
+  // Ensure the first character is a digit
+  size_t i = skip_whitespace(str);
+  if (!is_digit(str[i])) {
+    return result(EXESS_EXPECTED_DIGIT, i);
+  }
+
+  // Skip leading zeros
+  int n_zeroes = 0;
+  while (str[i] == '0') {
+    ++i;
+    ++n_zeroes;
+  }
+
+  // Read digits
+  for (; is_digit(str[i]); ++i) {
+    const uint64_t next = (*out * 10u) + (uint64_t)(str[i] - '0');
+    if (next < *out) {
+      *out = 0;
+      return result(EXESS_OUT_OF_RANGE, i);
+    }
+
+    *out = next;
+  }
+
+  return end_read(EXESS_SUCCESS, str, i);
+}
+
+ExessResult
+write_digits(const uint64_t value,
+             const size_t   buf_size,
+             char* const    buf,
+             const size_t   i)
+{
+  const uint8_t n_digits = exess_num_digits(value);
+  if (!buf) {
+    return result(EXESS_SUCCESS, n_digits);
+  }
+
+  if (i + n_digits >= buf_size) {
+    return end_write(EXESS_NO_SPACE, buf_size, buf, 0);
+  }
+
+  // Point s to the end
+  char* s = buf + i + n_digits - 1u;
+
+  // Write integer part (right to left)
+  uint64_t remaining = value;
+  do {
+    *s-- = (char)('0' + (remaining % 10));
+  } while ((remaining /= 10) > 0);
+
+  return result(EXESS_SUCCESS, n_digits);
+}
+
+ExessResult
+exess_write_ulong(const uint64_t value, const size_t buf_size, char* const buf)
+{
+  if (!buf) {
+    return result(EXESS_SUCCESS, exess_num_digits(value));
+  }
+
+  const ExessResult r = write_digits(value, buf_size, buf, 0);
+  return end_write(r.status, buf_size, buf, r.count);
+}