Show HN: val – An arbitrary precision calculator language

(github.com)

34 points | by crap 2 days ago ago

19 comments

  • primitivesuave 2 days ago ago

    The UI is awesome, amazing work! However, arbitrary precision implies that there is no fixed upper limit to the number of digits - simple tests like `0.1 + 0.2 == 0.3` and `2^53 == 2^53 + 1` (both produce "false") indicates you're still using IEEE 754 double precision floats.

    If "arbitrary precision" is not as important to you as "high precision", a 128 bit decimal has enough precision for 99% of real-world applications.

    • crap 2 days ago ago

      Thanks for checking it out! Should have been more clear that this is actively being worked on. This is ultimately the goal, and I'm currently working on integrating `astro_float` as the base for numbers.

      • primitivesuave 2 days ago ago

        That is awesome, I look forward to following the project and hopefully contributing! I became a better Rust programmer from reading your code :)

    • johannesrexx 21 hours ago ago

      Rewrite it like so

      > 1/10 + 2/10 == 3/10 true >

    • jdhwosnhw 2 days ago ago

      Do you mean, the first returns false and the second returns true?

      • primitivesuave 2 days ago ago

        Ah you're right, thank you for pointing it out!

        In the previous version of this comment (where I was still reading it incorrectly) I added a fun fact, that the significand of an IEEE 754 double-precision float is only allocated 52 bits, but the "hidden bit trick" provides an extra bit of precision when the normalized form starts with 1.

  • crap 2 days ago ago

    Thanks to everyone who gave feedback!

    Arbitrary precision is now supported in 0.3.0 after integrating the `astro_float` (https://docs.rs/astro-float/latest/astro_float/index.html) `BigFloat` type as the base for numbers in the language.

    Still working out the kinks, but its live so give it a try!

  • occamatl 2 days ago ago

    > sqrt(10^100)-1 -> 100000000000000000000000000000000000000000000000000

    Not what I expected.

  • jasonjmcghee 2 days ago ago

    Hey nice! We have similar interests. I built something similar, but with way less calculator functionality than you did :D

    But the main idea I was going for was real-time JIT evaluation with rendered errors (specifically learning / using cranelift JIT) - less to do with the calculator aspect.

    I ended up choosing miette for errors.

    https://github.com/jasonjmcghee/basic-treesitter-cranelift-j...

  • lttlrck 2 days ago ago

    This is cool.

    It love to have to base conversion functions, even if it's print only. Does that fit at all?

    • crap a day ago ago

      This definitely fits, base conversion is on the roadmap!

    • lttlrck a day ago ago

      and different input base notations, 0x, o, 0b etc

  • librasteve 14 hours ago ago

    very cool, welcome to the small club of CLI calculator authors! before I read this I knew of frink and crag (https://raku.land/zef:librasteve/App::Crag since you ask)

    Crag is built on raku so has some neat tricks up its sleeve - you can see Crag of the Day to see some in action...

      crag '0.1+0.2=0.2'   #True (arbitrary precision)
      crag '₃₆123.45'      #3F.G77777  (base 36)
      crag 'e ** (i * π) =~= -1'   #True  (math symbols, complex numbers)
      crag '0rMCMXLIV'     #1944 (Roman numerals)
      crag '^<௪௨ mph>'     #42mph  (Unicode and units)
    
    hee hee
  • I_complete_me 2 days ago ago

    I wish you well. And I clicked you a star on github. Keep up the good work.