too fucking tired... going to bed

src/wfc_eval_context.erl

@@ -0,0 +1,41 @@
+-module(wfc_eval_context).
+
+-export_type([
+    context/0
+]).
+
+-export([
+    new/0,
+    default/0,
+    define/3,
+    resolve_pattern/2
+]).
+
+-type sentence() :: wfc_sentence:sentence().
+
+-record(ctx,
+        {snowflakes :: #{binary() := fun()},
+         patterns   :: #{binary() := sentence()}}).
+
+-opaque context() :: #ctx{}.
+
+
+new() ->
+    #ctx{snowflakes = #{},
+         patterns   = #{}}.
+
+
+%% FIXME
+default() ->
+    new().
+
+
+define(Pat, Sentence, Ctx = #ctx{patterns = OldPatterns}) ->
+    NewPatterns = maps:put(Pat, Sentence, OldPatterns),
+    {ok, Ctx#ctx{patterns = NewPatterns}}.
+
+resolve_pattern(Pat, Ctx = #ctx{patterns = Patterns}) ->
+    case maps:find(Pat, Patterns) of
+        error -> {error, wfc_utils:str("wfc_eval_context:resolve_pattern: not found: ~w; context: ~w", [Pat, Ctx])};
+        Result -> Result
+    end.