public static ParsedDecimal from()

in src/main/java/org/apache/commons/text/numbers/ParsedDecimal.java [144:204]
39 lines of code
12 McCabe index (conditional complexity)

    public static ParsedDecimal from(final double d) {
        if (!Double.isFinite(d)) {
            throw new IllegalArgumentException("Double is not finite");
        }

        // Get the canonical string representation of the double value and parse
        // it to extract the components of the decimal value. From the documentation
        // of Double.toString() and the fact that d is finite, we are guaranteed the
        // following:
        // - the string will not be empty
        // - it will contain exactly one decimal point character
        // - all digit characters are in the ASCII range
        final char[] strChars = Double.toString(d).toCharArray();

        final boolean negative = strChars[0] == MINUS_CHAR;
        final int digitStartIdx = negative ? 1 : 0;

        final int[] digits = new int[strChars.length - digitStartIdx - 1];

        boolean foundDecimalPoint = false;
        int digitCount = 0;
        int significantDigitCount = 0;
        int decimalPos = 0;

        int i;
        for (i = digitStartIdx; i < strChars.length; ++i) {
            final char ch = strChars[i];

            if (ch == DECIMAL_SEP_CHAR) {
                foundDecimalPoint = true;
                decimalPos = digitCount;
            } else if (ch == EXPONENT_CHAR) {
                // no more mantissa digits
                break;
            } else if (ch != ZERO_CHAR || digitCount > 0) {
                // this is either the first non-zero digit or one after it
                final int val = digitValue(ch);
                digits[digitCount++] = val;

                if (val > 0) {
                    significantDigitCount = digitCount;
                }
            } else if (foundDecimalPoint) {
                // leading zero in a fraction; adjust the decimal position
                --decimalPos;
            }
        }

        if (digitCount > 0) {
            // determine the exponent
            final int explicitExponent = i < strChars.length
                    ? parseExponent(strChars, i + 1)
                    : 0;
            final int exponent = explicitExponent + decimalPos - significantDigitCount;

            return new ParsedDecimal(negative, digits, significantDigitCount, exponent);
        }

        // no non-zero digits, so value is zero
        return new ParsedDecimal(negative, new int[] {0}, 1, 0);
    }