Quote the name of the maybe/2 type

.github/workflows/build.yml

@@ -0,0 +1,44 @@
+name: Erlang CI
+
+on: [push]
+
+jobs:
+  build_and_test:
+    runs-on: ubuntu-latest
+    name: OTP ${{matrix.otp}}
+    strategy:
+      matrix:
+        otp: ["24.0", "25.0", "26.0", "27.0"]
+    steps:
+    - uses: actions/checkout@v2.0.0
+    - uses: erlef/setup-beam@v1.18.0
+      with:
+        otp-version: ${{ matrix.otp }}
+        rebar3-version: "3.23.0"
+    - name: Compile
+      run: make compile
+    - name: Run xref
+      run: make xref
+    - name: Run dialyzer
+      run: make dialyze
+    - name: Run eunit tests
+      run: make eunit
+
+  release:
+    if: github.ref == 'refs/heads/master' && startsWith(github.event.head_commit.message, 'no-release:') == false
+    needs: build_and_test
+    runs-on: ubuntu-latest
+    steps:
+    - name: Bump version and push tag
+      id: tag_version
+      uses: mathieudutour/github-tag-action@v5.3
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+    - name: Create a GitHub release
+      uses: actions/create-release@v1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      with:
+        tag_name: ${{ steps.tag_version.outputs.new_tag }}
+        release_name: Release ${{ steps.tag_version.outputs.new_tag }}
+        body: ${{ steps.tag_version.outputs.changelog }}

.gitignore

@@ -3,3 +3,5 @@ deps/
 *.app
 .eunit/
 *.plt
+_build
+/test_db*/

Makefile

@@ -0,0 +1,16 @@
+all: compile
+
+compile:
+	rebar3 compile
+
+clean:
+	rebar3 clean
+
+eunit:
+	rebar3 eunit
+
+dialyze:
+	rebar3 dialyzer
+
+xref:
+	rebar3 as test xref

README.md

@@ -19,13 +19,17 @@ jakob@sleepy.primat.es:~/git/stdlib2$ gmake test
 Manifest
 ========
 * include/:
-    * prelude.hrl        -- Useful macros and type aliases.
+    * prelude.hrl        -- Complete collection of macros and type aliases.
+    * byte.hrl           -- Macros and type aliases for byte unit conversion.
+    * maybe.hrl          -- Macros and type aliases for maybe monads.
+    * time.hrl           -- Macros and type aliases related to time and date.
 * src/:
     * s2_atoms.erl       -- Atom-related utilities.
     * s2_csets.erl       -- Counting sets.
     * s2_env.erl         -- Environment access and setup.
     * s2_export.erl      -- Export unexported functions from the REPL.
     * s2_fs.erl          -- Filesystem-related utilities.
+    * s2_functors.erl    -- The functor typeclass.
     * s2_funs.erl        -- Combinators.
     * s2_gen_db.erl      -- Behaviour for persistent state.
     * s2_gen_lattice.erl -- Behaviour for lattices.

include/byte.hrl

@@ -0,0 +1,13 @@
+-ifndef(__S2_BYTE_HRL).
+-define(__S2_BYTE_HRL, true).
+
+-define(BITS(Bytes), (Bytes * 8)).
+-define(BYTES(Bits), (Bits div 8)).
+
+-define(KB(X), (X * 1024)).
+-define(MB(X), (X * 1024 * 1024)).
+-define(GB(X), (X * 1024 * 1024 * 1024)).
+-define(TB(X), (X * 1024 * 1024 * 1024 * 1024)).
+-define(PB(X), (X * 1024 * 1024 * 1024 * 1024 * 1024)).
+
+-endif.

include/maybe.hrl

@@ -0,0 +1,126 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%% @doc Maybe Monads
+%%% @end
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%%%_* Types ============================================================
+-type functor(A)    :: s2_functors:functor(A).
+-type thunk(A)      :: fun(() -> A).
+-type collection(A) :: [A] | #{_ := A}.
+
+-type ok(A)       :: {ok, A}.
+-type error(A)    :: {error, A}.
+-type 'maybe'(A, B) :: ok(A) | error(B).
+-type whynot(A)   :: ok | error(A).
+
+%%%_* Macros ===========================================================
+-define(lift(E),   s2_maybe:lift(fun() -> E end)).
+-define(unlift(E), s2_maybe:unlift(fun() -> E end)).
+
+-define(do(F0, F1),
+        s2_maybe:do([F0, F1])).
+-define(do(F0, F1, F2),
+        s2_maybe:do([F0, F1, F2])).
+-define(do(F0, F1, F2, F3),
+        s2_maybe:do([F0, F1, F2, F3])).
+-define(do(F0, F1, F2, F3, F4),
+        s2_maybe:do([F0, F1, F2, F3, F4])).
+-define(do(F0, F1, F2, F3, F4, F5),
+        s2_maybe:do([F0, F1, F2, F3, F4, F5])).
+-define(do(F0, F1, F2, F3, F4, F5, F6),
+        s2_maybe:do([F0, F1, F2, F3, F4, F5, F6])).
+-define(do(F0, F1, F2, F3, F4, F5, F6, F7),
+        s2_maybe:do([F0, F1, F2, F3, F4, F5, F6, F7])).
+-define(do(F0, F1, F2, F3, F4, F5, F6, F7, F8),
+        s2_maybe:do([F0, F1, F2, F3, F4, F5, F6, F7, F8])).
+-define(do(F0, F1, F2, F3, F4, F5, F6, F7, F8, F9),
+        s2_maybe:do([F0, F1, F2, F3, F4, F5, F6, F7, F8, F9])).
+
+-define(fmap(F, Functor),
+        s2_functors:fmap(F, Functor)).
+
+-define(ido(F0, F1),
+        ?ido([F0, F1])).
+-define(ido(F0, F1, F2),
+        ?ido([F0, F1, F2])).
+-define(ido(F0, F1, F2, F3),
+        ?ido([F0, F1, F2, F3])).
+-define(ido(F0, F1, F2, F3, F4),
+        ?ido([F0, F1, F2, F3, F4])).
+-define(ido(F0, F1, F2, F3, F4, F5),
+        ?ido([F0, F1, F2, F3, F4, F5])).
+-define(ido(F0, F1, F2, F3, F4, F5, F6),
+        ?ido([F0, F1, F2, F3, F4, F5, F6])).
+-define(ido(F0, F1, F2, F3, F4, F5, F6, F7),
+        ?ido([F0, F1, F2, F3, F4, F5, F6, F7])).
+-define(ido(F0, F1, F2, F3, F4, F5, F6, F7, F8),
+        ?ido([F0, F1, F2, F3, F4, F5, F6, F7, F8])).
+-define(ido(F0, F1, F2, F3, F4, F5, F6, F7, F8, F9),
+        ?ido([F0, F1, F2, F3, F4, F5, F6, F7, F8, F9])).
+
+%% Instrumented do.
+-define(ido(Fs),
+        (case ?TIME(?FUNCTION, s2_maybe:do(Fs)) of
+           {ok, ___Res} = ___Ok ->
+             ?debug("~p: ok: ~p", [?FUNCTION, ___Res]),
+             ?increment(?FUNCTION, ok),
+             ___Ok;
+           {error, ___Rsn} = ___Err ->
+             ?error("~p: error: ~p", [?FUNCTION, ___Rsn]),
+             ?increment(?FUNCTION, error),
+             ___Err
+         end)).
+
+-define(thunk(E0),
+        fun() -> E0 end).
+-define(thunk(E0, E1),
+        fun() -> E0, E1 end).
+-define(thunk(E0, E1, E2),
+        fun() -> E0, E1, E2 end).
+-define(thunk(E0, E1, E2, E3),
+        fun() -> E0, E1, E2, E3 end).
+-define(thunk(E0, E1, E2, E3, E4),
+        fun() -> E0, E1, E2, E3, E4 end).
+-define(thunk(E0, E1, E2, E3, E4, E5),
+        fun() -> E0, E1, E2, E3, E4, E5 end).
+-define(thunk(E0, E1, E2, E3, E4, E5, E6),
+        fun() -> E0, E1, E2, E3, E4, E5, E6 end).
+-define(thunk(E0, E1, E2, E3, E4, E5, E6, E7),
+        fun() -> E0, E1, E2, E3, E4, E5, E6, E7 end).
+-define(thunk(E0, E1, E2, E3, E4, E5, E6, E7, E8),
+        fun() -> E0, E1, E2, E3, E4, E5, E6, E7, E8 end).
+-define(thunk(E0, E1, E2, E3, E4, E5, E6, E7, E8, E9),
+        fun() -> E0, E1, E2, E3, E4, E5, E6, E7, E8, E9 end).
+
+-define(liftm(F, A1),
+        s2_maybe:liftm(F, [?thunk(A1)])).
+-define(liftm(F, A1, A2),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2)])).
+-define(liftm(F, A1, A2, A3),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3)])).
+-define(liftm(F, A1, A2, A3, A4),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4)])).
+-define(liftm(F, A1, A2, A3, A4, A5),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4),
+                           ?thunk(A5)])).
+-define(liftm(F, A1, A2, A3, A4, A5, A6),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4),
+                           ?thunk(A5), ?thunk(A6)])).
+-define(liftm(F, A1, A2, A3, A4, A5, A6, A7),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4),
+                           ?thunk(A5), ?thunk(A6), ?thunk(A7)])).
+-define(liftm(F, A1, A2, A3, A4, A5, A6, A7, A8),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4),
+                           ?thunk(A5), ?thunk(A6), ?thunk(A7), ?thunk(A8)])).
+-define(liftm(F, A1, A2, A3, A4, A5, A6, A7, A8, A9),
+        s2_maybe:liftm(F, [?thunk(A1), ?thunk(A2), ?thunk(A3), ?thunk(A4),
+                           ?thunk(A5), ?thunk(A6), ?thunk(A7), ?thunk(A8),
+                           ?thunk(A9)])).
+
+%%%_* Guards ===========================================================
+-define(is_thunk(X), is_function(X, 0)).
+
+%%% Local Variables:
+%%% allout-layout: t
+%%% erlang-indent-level: 2
+%%% End: