1 files changed, 74 insertions, 0 deletions
diff --git a/aoc2023/build/packages/snag/src/snag.erl b/aoc2023/build/packages/snag/src/snag.erl
new file mode 100644
index 0000000..a07f242
--- /dev/null
+++ b/aoc2023/build/packages/snag/src/snag.erl
@@ -0,0 +1,74 @@
+-module(snag).
+-compile([no_auto_import, nowarn_unused_vars]).
+
+-export([new/1, error/1, layer/2, context/2, pretty_print/1, line_print/1]).
+-export_type([snag/0]).
+
+-type snag() :: {snag, binary(), list(binary())}.
+
+-spec new(binary()) -> snag().
+new(Issue) ->
+    {snag, Issue, []}.
+
+-spec error(binary()) -> {ok, any()} | {error, snag()}.
+error(Issue) ->
+    {error, new(Issue)}.
+
+-spec layer(snag(), binary()) -> snag().
+layer(Snag, Issue) ->
+    {snag, Issue, [erlang:element(2, Snag) | erlang:element(3, Snag)]}.
+
+-spec context({ok, EXX} | {error, snag()}, binary()) -> {ok, EXX} |
+    {error, snag()}.
+context(Result, Issue) ->
+    case Result of
+        {ok, _} ->
+            Result;
+
+        {error, Snag} ->
+            {error, layer(Snag, Issue)}
+    end.
+
+-spec pretty_print_cause(list(binary())) -> gleam@string_builder:string_builder().
+pretty_print_cause(Cause) ->
+    _pipe = Cause,
+    _pipe@1 = gleam@list:index_map(
+        _pipe,
+        fun(Index, Line) ->
+            gleam@string:concat(
+                [<<"  "/utf8>>,
+                    gleam@int:to_string(Index),
+                    <<": "/utf8>>,
+                    Line,
+                    <<"\n"/utf8>>]
+            )
+        end
+    ),
+    gleam@string_builder:from_strings(_pipe@1).
+
+-spec pretty_print(snag()) -> binary().
+pretty_print(Snag) ->
+    Builder = gleam@string_builder:from_strings(
+        [<<"error: "/utf8>>, erlang:element(2, Snag), <<"\n"/utf8>>]
+    ),
+    gleam@string_builder:to_string(case erlang:element(3, Snag) of
+            [] ->
+                Builder;
+
+            Cause ->
+                _pipe = Builder,
+                _pipe@1 = gleam@string_builder:append(
+                    _pipe,
+                    <<"\ncause:\n"/utf8>>
+                ),
+                gleam@string_builder:append_builder(
+                    _pipe@1,
+                    pretty_print_cause(Cause)
+                )
+        end).
+
+-spec line_print(snag()) -> binary().
+line_print(Snag) ->
+    _pipe = [gleam@string:append(<<"error: "/utf8>>, erlang:element(2, Snag)) |
+        erlang:element(3, Snag)],
+    gleam@string:join(_pipe, <<" <- "/utf8>>).