Ruby bindings for libspelling, the spell checker GNOME Text Editor and Builder use: a GObject front end over enchant, plus the GtkSourceView adapter that underlines misspellings as they are typed.
require "libspelling"
provider = Spelling::Provider.default
provider.display_name # => "Enchant"
provider.default_code # => "en_GB", or nil where enchant found no dictionary
checker = Spelling::Checker.default
checker.check_word("the", -1) # => true (-1 means NUL-terminated)
checker.list_corrections("teh") # => ["the", ...], or nil with no dictionaryThe Ruby namespace is Spelling, not Libspelling: it is the namespace the
typelib declares, and only the gem is named after the shared library.
None of this needs a display or a main loop. spelling_init — which the loader
calls for you — registers the library's types and its enchant provider and
touches no GdkDisplay, so word lookups work headless and in CI.
Spelling::TextBufferAdapter is the exception, as it wants a real
GtkSource::Buffer: for that, add the
gtksourceview5 gem and build it
inside your GTK application.
The library ships a GObject Introspection typelib — Spelling-1.typelib —
describing every class, method, property and signal it has. Spelling::Loader
hands that to ruby-gnome's GObjectIntrospection::Loader, which defines the
Ruby classes from it at require time. The loader is thirty lines, most of them
comment.
So this gem is pure Ruby: no extension of its own, no Cargo workspace, no per-platform binary. You get the whole library rather than the subset somebody got round to wrapping by hand, and it does not drift when libspelling gains API.
Be precise about install, though. gem install libspelling still compiles C,
because gobject-introspection and glib2 are themselves native extensions
built against glib, so a compiler and glib's development headers are needed.
What this gem adds on top is nothing: it has no build step of its own, and
those two extensions are the ones every ruby-gnome application already has,
since gtk4 depends on them.
This is how ruby-gnome itself ships gtksourceview5, libsecret and the rest.
The typelib is a C-library artefact, so it belongs to your distribution and this gem cannot install it:
| Debian / Ubuntu | gir1.2-spelling-1 (the library itself is libspelling-1-2) |
| Fedora | libspelling |
| Arch | libspelling |
| nix | pkgs.libspelling |
Spelling-1.typelib names GtkSource-5, Gtk-4.0 and Gio-2.0, and the
loader follows those at require time, so gtksourceview5's and gtk4's typelibs
have to be installed too — gir1.2-gtksource-5 and gir1.2-gtk-4.0 on Debian,
and the main packages elsewhere. Without them the require fails as
Typelib file for namespace 'GtkSource' not found.
If any of it is outside the default search path, point GI_TYPELIB_PATH at the
directories holding the typelibs. The dev shell in flake.nix does this.
Note the version: libspelling 0.4 ships Spelling-1.typelib, with a bare 1
where most GNOME libraries would have 1.0. That is the version string the
loader passes, and the reason it is worth reading off the installed file rather
than guessing.
One trap worth knowing. The typelib must come from the same glib build as
the gobject-introspection gem. Mixing two registers GIO twice in one process
and fails with cannot register existing type 'GTlsCertificate'. Under nix,
take both from one nixpkgs — and note that glib's typelibs live in its out
output, not the default one.
The gem needs Spelling-1.typelib and everything that typelib declares, resolved
transitively by the loader at require time. A missing one surfaces as
Typelib file for namespace 'X' not found, one at a time, so the whole chain
is listed here rather than discovered by repeated failure:
pkgs.libspelling— its typelib, which is whereSpelling-1.typeliblivespkgs.gtksourceview5— GtkSource-5pkgs.gtk4— Gtk-4.0, and through it Gdk, Gsk and Graphenepkgs.pango— Pango-1.0 and PangoCairo-1.0pkgs.gdk-pixbuf— GdkPixbuf-2.0pkgs.graphene— Graphene-1.0, the viewport mathspkgs.harfbuzz— HarfBuzz-0.0pkgs.gobject-introspection— its typelibpkgs.glib— GLib-2.0, GObject-2.0 and Gio-2.0, which nearly every GNOME typelib declares
Note the .out: a package's default output is often bin, which carries no
typelibs. makeSearchPath takes the first output, so it has to be asked for
out explicitly — this is the single most common way to get a search path that
looks right and finds nothing.
{
inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
outputs = { nixpkgs, ... }:
let
system = "x86_64-linux";
pkgs = nixpkgs.legacyPackages.${system};
typelibPath = pkgs.lib.makeSearchPath "lib/girepository-1.0"
(map (drv: drv.out or drv) [ pkgs.libspelling pkgs.gtksourceview5 pkgs.gtk4 pkgs.pango pkgs.gdk-pixbuf pkgs.graphene pkgs.harfbuzz pkgs.gobject-introspection pkgs.glib ]);
in
{
devShells.${system}.default = pkgs.mkShell {
packages = [ pkgs.ruby_3_4 pkgs.bundler ] ++ [ pkgs.libspelling pkgs.gtksourceview5 pkgs.gtk4 pkgs.pango pkgs.gdk-pixbuf pkgs.graphene pkgs.harfbuzz pkgs.gobject-introspection pkgs.glib ];
shellHook = ''
export GI_TYPELIB_PATH="${typelibPath}''${GI_TYPELIB_PATH:+:$GI_TYPELIB_PATH}"
'';
};
};
}Everything must come from one nixpkgs. A typelib built against a different
glib than the gobject-introspection gem registers GIO twice in the process
and fails with cannot register existing type 'GTlsCertificate'.
If you are packaging an application rather than entering a shell, the same
typelibPath goes on the wrapper:
makeWrapper ${ruby}/bin/ruby $out/bin/my-app \
--set GI_TYPELIB_PATH "${typelibPath}"nix develop
bin/testThe suite runs headless, which is part of what it checks.
gem kit releaseThat is the whole thing. It gates on the changelog having an entry for this version, on no deprecation deadline coming due, and on a clean working tree; then builds, pushes and tags.
There is nothing to wait for in CI. This gem is pure Ruby, so gem build
produces one libspelling-X.Y.Z.gem that is the same artefact wherever it is built —
no extension, no per-platform gems, nothing for a workflow to hand back.
Apache-2.0. libspelling itself is LGPL-2.1-or-later; this gem links nothing and copies no libspelling code — it reads a description of it at runtime.