Convert hexadecimal color triplet to decimal

_Andrew · August 11, 2023, 9:40pm

Given a color as an RGB hex triplet, is there a way in Nix to convert it into decimal values? e.g.:

parseHexColor "#0080ff" == [ 0 128 255 ]

colemickens · August 12, 2023, 3:20am

github.com

Misterio77/nix-colors/blob/b92df8f5eb1fa20d8e09810c03c9dc0d94ef2820/lib/core/conversions.nix#L87


      
               hex: A hexadecimal string.
          
          
   Example:
               hexadecimal "12"
               => 18
               hexadecimal "FF"
               => 255
               hexadecimal "abcdef"
               => 11259375
          */
          hexToDec = hex:
            let
              inherit (nixpkgs-lib) stringToCharacters reverseList imap0 foldl;
              decimals = builtins.map hexCharToDec (stringToCharacters hex);
              decimalsAscending = reverseList decimals;
              decimalsPowered = imap0 base16To10 decimalsAscending;
            in
            foldl builtins.add 0 decimalsPowered;
          
          
/* Converts a 6 character hexadecimal string to RGB values.

_Andrew · August 12, 2023, 3:10pm

Wonderful, thanks. Amusing that they even had to implement pow and a digit lookup table.