YEISON

Just another "because we can™" library by yours truly.

Yeison is an heterogeneous container for general types, essentially equivalent to JSON, TOML, YAML text file representations. It is also an experiment on using new Ada 2022 features to enable simpler initializations and pushing them to their limits. As such, it requires the latest GNAT compiler you can find packaged in Alire.

With this library, these kind of declarations are possible:

with Yeison;

package Examples is

   Number : constant Yeison.Int  := 3;
   Real   : constant Yeison.Real := 3.14;
   Text   : constant Yeison.Str  := "Some Unicode text: Mi ĝuas la Adan programlingvon";

   Vector : constant Yeison.Vec := (1, 2.0, "three");
   Map    : constant Yeison.Map := ("1" => 1, "2" => 2.0, "3" => "three");

   V2     : constant Yeison.Vec := (Vector, Map, Number, Real, Text);
   --  With nested vectors and maps inside a root vector

   M2     : constant Yeison.Map := ("vec" => V2, "map" => Map);
   --  With nested vectors and maps inside a root map

   M3     : constant Yeison.Map := ("one" => 1, 
                                    "two" => Yeison.Map'(2, Yeison.Vec'(3, 4, 5)));
   --  Inline initialization of nested structures

end Examples;

More examples available in the demo subfolder (which is also an Alire crate so you can alr run it).

Accessing the values in these containers is done with the usual notation but also relying on Yeison vectors for multilevel indexing:

pragma Assert (Vector (2)        = 2.0);
pragma Assert (Map ("3")         = "three");
pragma Assert (V2  (1)(2)        = 2.0);
pragma Assert (V2 ((1, 2))       = 2.0);
pragma Assert (M2  ("map")("3")  = "three");
pragma Assert (M2 (("map", "3")) = "three");

Since this library has not been conceived with extreme efficiency in mind, but to allow flexible use, it internally stores numbers as Big_Integers or Big_Reals, and strings as Unicode, so at least you do not have to worry about limits.

Using Yeison in your projects

At the time Yeison has no dependencies, so you can download it and use it normally as any other GNAT project through the provided GPR project file.

If using Alire, since it is not yet indexed, you can add it as a dependency of your project with

alr with --use=https://github.com/mosteo/yeison