ada-toml
is a pure Ada library for parsing and creating TOML documents.
The development of this library started recently and it currently lacks several important features, mainly: support for floating-point and date/time values.
With an Ada 2012 compiler and GPRbuild, building the library is as simple as running:
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
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);