76 lines
1.6 KiB
C++
76 lines
1.6 KiB
C++
#include <NumberParsing.h>
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// This function assumes you have called is_valid_digit_for_base() to validate the digit first.
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static isize parse_digit_unchecked(char c)
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{
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if (_isdigit(c)) return c - '0';
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if (_islower(c)) return (c - 'a') + 10;
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return (c - 'A') + 10;
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}
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static bool is_valid_digit_for_base(int base, char c)
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{
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if (!_isalnum(c)) return false;
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if (parse_digit_unchecked(c) >= (isize)base) return false;
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return true;
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}
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usize _strtou(const char* str, const char** endptr, int base)
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{
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usize val = 0;
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while (_isspace(*str)) str++;
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if ((base == 0 || base == 16) && *str == '0')
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{
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str++;
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if (_tolower(*str) == 'x')
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{
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base = 16;
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str++;
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}
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else if (base == 0)
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base = 8;
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}
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else if (base == 0)
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base = 10;
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while (is_valid_digit_for_base(base, *str))
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{
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val = (base * val) + parse_digit_unchecked(*str);
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str++;
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}
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if (endptr) *endptr = str;
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return val;
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}
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isize _strtoi(const char* str, const char** endptr, int base)
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{
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bool negative = false;
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while (_isspace(*str)) str++;
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if (*str == '-' || *str == '+')
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{
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if (*str == '-') negative = true;
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str++;
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}
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usize rc = _strtou(str, endptr,
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base); // FIXME: Check for overflow (the unsigned usize value might not fit into a signed isize)
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return negative ? -(isize)rc : (isize)rc;
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}
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usize _atou(const char** str)
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{
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return _strtou(*str, str, 10);
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}
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isize _atos(const char** str)
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{
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return _strtoi(*str, str, 10);
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}
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