Practices for writing high-performance Go

Post by igouy » Tue, May 07, 2019, 4:07 PM UTC

v_lisivka wrote: post #84

galangalalgol wrote: post #67

Earlier quoted context omitted.

The benchmark game puts c, rust, and c++, in that order, roughly on par in performance, with go being about 2-3x slower. No idea if that's accurate. Sampling bias means people who like performance are optimizing the languages used for performance, and people who just like to get something working quit after the first benchmark in go or python is finished. https://benchmarksgame-team.pages.debian.net/benchmarksgame/..…

If you discard regexredux, then Rust is faster than C and C++ at average: see average bar at "How many times slower graph" [1]. regexredux program is outlier in Rust, because replacement of a regex in string is slower in regex crate, because author of regex crate chose to implement safer, but slower algorithm. To fix this, regex crate must be updated or replaced. I spent two weekends on this. [1]: https://benchmarksg…

Post by networkimprov » Tue, May 07, 2019, 6:23 PM UTC

icebraining wrote: post #73

networkimprov wrote: post #41

Earlier quoted context omitted.

My point is that you should file a Github issue if there isn't one.

Why "should"? Nobody owes the writing of issues.

Post by v_lisivka » Tue, May 07, 2019, 8:10 PM UTC

igouy wrote: post #91

v_lisivka wrote: post #84

Earlier quoted context omitted.

If you discard regexredux, then Rust is faster than C and C++ at average: see average bar at "How many times slower graph" [1]. regexredux program is outlier in Rust, because replacement of a regex in string is slower in regex crate, because author of regex crate chose to implement safer, but slower algorithm. To fix this, regex crate must be updated or replaced. I spent two weekends on this. [1]: https://benchmarksg…

mandelbrot is outlier in Rust, because… :-)

Post by Const-me » Wed, May 08, 2019, 12:16 AM UTC

neop1x wrote: post #96

Const-me wrote: post #90

Earlier quoted context omitted.

> it aims to be feature-rich Visual basic had a Replace() function back in 1998, to replace substrings. C++ now has many amazingly advanced high-level features, but still no built-in way to replace a substring. I don’t think I needed to write my own string replacing function in any other language I used (I’ve been programming for living since 2000). I like C++ and use it a lot. But these seemingly small issues with i…

String operations of C look so much cleaner and complete than those "algorithmic and templating" ones of C++. And C++ can quickly become difficult to read after overloading various operators on classes or after using fancier less-known features. I personally find C++ too complex and confusing. I know Google dictates some reasonable subset of C++ for Fuchia and that is good. Btw also the dependency management is somet…

Post by v_lisivka » Wed, May 08, 2019, 9:21 AM UTC

igouy wrote: post #98

v_lisivka wrote: post #84

Earlier quoted context omitted.

If you discard regexredux, then Rust is faster than C and C++ at average: see average bar at "How many times slower graph" [1]. regexredux program is outlier in Rust, because replacement of a regex in string is slower in regex crate, because author of regex crate chose to implement safer, but slower algorithm. To fix this, regex crate must be updated or replaced. I spent two weekends on this. [1]: https://benchmarksg…

> To fix this, regex crate must be updated or replaced. I somehow doubt pcre2 is being changed to make the tiny toy C programs run better. > I spent two weekends on this. So shouldn't we assume the program performance simply reflects all-those-hours you've spent working on it?

  fn find_replaced_sequence_length(sequence: String) -> usize {
    // Replace the following patterns, one at a time:
    let substs = vec![
        ("tHa[Nt]", ""),
        ("aND|caN|Ha[DS]|WaS", ""),
        ("a[NSt]|BY", ""),
        ("]*>", "|"),
        ("\\|[^|][^|]*\\|", "-"),
    ];
  
    // Perform the replacements in the sequence:
    substs
        .iter()
        .fold(sequence, |s, (re, replacement)| {
            regex(re)
                .replace_all(&s, NoExpand(replacement)).into_owned()
        }).len()
  }