ada-toml: TOML parser for Ada

ada-toml is a pure Ada library for parsing and creating TOML documents. It conforms to the version 1.0.0 of the format standard.

Build and install

With an Ada 2012 compiler and GPRbuild, building and installing the library is as simple as running:

$ make
$ sudo make install

If you don't want to install in /usr, you can replace the last command with:

$ sudo make install prefix=/where/to/install

Note that the Makefile is just a wrapper around gprbuild and gprinstall to make it easy for users and packagers. You can also run them manually:

gprbuild -Pada_toml.gpr -p

This will build in debug mode and produce a static library. In order to build in production mode, add -XBUILD_MODE=prod, and to build a dynamic library, add -XLIBRARY_TYPE=static.

Installation to $PREFIX is simply done using GPRinstall:

gprinstall -Pada_toml.gpr --prefix=$PREFIX

See TESTING.rst to run the testsuite.

Quick tutorial

All basic types and subprograms are in the TOML package. All "nodes" in a TOML documents are materialized using the TOML.TOML_Value type. Since TOML values make up a tree, this type has reference semantics. This means that modifying a TOML node does not modify the corresponding TOML_Value value itself, but rather the TOML value that is referenced.

Parsing a TOML file is as easy as using the TOML.File_IO.Load_File function:

declare
   Result : constant TOML.Read_Result :=
      TOML.File_IO.Load_File ("config.toml");
begin
   if Result.Success then
      Ada.Text_IO.Put_Line ("config.toml loaded with success!");
   else
      Ada.Text_IO.Put_Line ("error while loading config.toml:");
      Ada.Text_IO.Put_Line
         (Ada.Strings.Unbounded.To_String (Result.Message));
   end if;
end;

Each TOML value has kind, defining which data it contains (a boolean, an integer, a string, a table, ...). To each kind, one or several primitives are associated to let one process the underlying data:

case Result.Kind is
   when TOML.TOML_Boolean =>
      Ada.Text_IO.Put_Line ("Boolean: " & Result.As_Boolean'Image);

   when TOML.TOML_Integer =>
      Ada.Text_IO.Put_Line ("Boolean: " & Result.As_Integer'Image);

   when TOML.TOML_String =>
      Ada.Text_IO.Put_Line ("Boolean: " & Result.As_String);

   when TOML.TOML_Array =>
      Ada.Text_IO.Put_Line ("Array of " & Result.Length & " elements");

   when others =>
      null;
end case;

There are also primitives to build TOML values:

declare
   Bool : constant TOML.TOML_Value := TOML.Create_Boolean (False);
   Int  : constant TOML.TOML_Value := TOML.Create_Integer (10);
   Str  : constant TOML.TOML_Value := TOML.Create_String ("Hello, world");

   Table : constant TOML.TOML_Value := TOML.Create_Table;
begin
   Table.Set ("bool_field", Bool);
   Table.Set ("int_field", Int);
   Table.Set ("str_field", Str);
end;

And finally one can turn a tree of TOML nodes back in text form:

Ada.Text_IO.Put_Line ("TOML document:");
Ada.Text_IO.Put_Line (Table.Dump_As_String);

Contributing

The development of ada-toml happens on GitHub. Everyone is welcome to contribute to this project: please read our contribution rules if you consider doing so.