FastDoubleParser: Java port of Daniel Lemires fast_double_parser

Re:FastDoubleParser: Java port of Daniel Lemires fast_double... by slavik81 on Monday March 22, 2021 @06:24PM (#26548153)

To me, the original C-style code looks nicer than the Java.

C++:

    bool found_minus = (*p == '-');
    bool negative = false;
    if (found_minus) {
      ++p;
      negative = true;
      if (!is_integer(*p)) { // a negative sign must be followed by an integer
        return nullptr;
      }
    }

Java:

    int strlen = str.length();
    if (strlen == 0) {
        throw new NumberFormatException("empty String");
    }
    int index = 0;
    char ch = str.charAt(index);

    boolean negative = false;
    if (ch == '-') {
        negative = true;
        ch = ++index < strlen ? str.charAt(index) : 0;
        if (ch == 0) {
            throw new NumberFormatException("'-' cannot stand alone");
        }
    }

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Re:FastDoubleParser: Java port of Daniel Lemires fast_double... by slavik81 on Tuesday March 23, 2021 @12:44AM (#26551216)

I suppose the main point I was trying to convey is that the code snippet gopalv quoted is not ugly because it's C-like. That ternary expression doesn't appear in the original C++ implementation at all. Many of the things people are complaining about—like relying on the return value of a prefix increment—are only in the Java version.

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