Add some list-related NIFs

CHANGELOG.md

@@ -55,6 +55,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `supervisor:which_children/1` and `supervisor:count_children/1`
 - Added `monitored_by` in `process_info/2`
 - Added mock implementation for `current_stacktrace` in `process_info`
+- Added `erlang:list_to_bitstring`
+- Reimplemented `lists:keyfind`, `lists:keymember` and `lists:member` as NIFs
 
 ### Changed
 

libs/estdlib/src/lists.erl

@@ -135,11 +135,7 @@ last([_H | T]) -> last(T).
 %%-----------------------------------------------------------------------------
 -spec member(E :: term(), L :: list()) -> boolean().
 member(_, []) ->
-    false;
-member(E, [E | _]) ->
-    true;
-member(E, [_ | T]) ->
-    member(E, T).
+    erlang:nif_error(undefined).
 
 %%-----------------------------------------------------------------------------
 %% @param   E the member to delete
@@ -265,22 +261,8 @@ keydelete(K, I, [H | T], L2) ->
 %% @end
 %%-----------------------------------------------------------------------------
 -spec keyfind(K :: term(), I :: pos_integer(), L :: list(tuple())) -> tuple() | false.
-keyfind(_K, _I, []) ->
-    false;
-keyfind(K, I, [H | T]) when is_tuple(H) ->
-    case I =< tuple_size(H) of
-        true ->
-            case element(I, H) of
-                K ->
-                    H;
-                _ ->
-                    keyfind(K, I, T)
-            end;
-        false ->
-            keyfind(K, I, T)
-    end;
-keyfind(K, I, [_H | T]) ->
-    keyfind(K, I, T).
+keyfind(_K, _I, _L) ->
+    erlang:nif_error(undefined).
 
 %%-----------------------------------------------------------------------------
 %% @param   K the key to match
@@ -292,21 +274,7 @@ keyfind(K, I, [_H | T]) ->
 %%-----------------------------------------------------------------------------
 -spec keymember(K :: term(), I :: pos_integer(), L :: list(tuple())) -> boolean().
 keymember(_K, _I, []) ->
-    false;
-keymember(K, I, [H | T]) when is_tuple(H) ->
-    case I =< tuple_size(H) of
-        true ->
-            case element(I, H) of
-                K ->
-                    true;
-                _ ->
-                    keymember(K, I, T)
-            end;
-        false ->
-            keymember(K, I, T)
-    end;
-keymember(K, I, [_H | T]) ->
-    keymember(K, I, T).
+    erlang:nif_error(undefined).
 
 %%-----------------------------------------------------------------------------
 %% @param   K           the key to match

src/libAtomVM/defaultatoms.def

@@ -194,3 +194,6 @@ X(INIT_ATOM, "\x4", "init")
 X(MONITORED_BY_ATOM, "\xC", "monitored_by")
 
 X(CURRENT_STACKTRACE_ATOM, "\x12", "current_stacktrace")
+
+X(KEY_ATOM, "\x3", "key")
+X(VALUE_ATOM, "\x5", "value")

src/libAtomVM/nifs.c

@@ -177,6 +177,7 @@ static term nif_erlang_setnode_2(Context *ctx, int argc, term argv[]);
 static term nif_erlang_memory(Context *ctx, int argc, term argv[]);
 static term nif_erlang_monitor(Context *ctx, int argc, term argv[]);
 static term nif_erlang_demonitor(Context *ctx, int argc, term argv[]);
+static term nif_erlang_list_to_bitstring_1(Context *ctx, int argc, term argv[]);
 static term nif_erlang_unlink(Context *ctx, int argc, term argv[]);
 static term nif_atomvm_add_avm_pack_binary(Context *ctx, int argc, term argv[]);
 static term nif_atomvm_add_avm_pack_file(Context *ctx, int argc, term argv[]);
@@ -197,6 +198,9 @@ static term nif_code_ensure_loaded(Context *ctx, int argc, term argv[]);
 static term nif_erlang_module_loaded(Context *ctx, int argc, term argv[]);
 static term nif_erlang_nif_error(Context *ctx, int argc, term argv[]);
 static term nif_lists_reverse(Context *ctx, int argc, term argv[]);
+static term nif_lists_keyfind(Context *ctx, int argc, term argv[]);
+static term nif_lists_keymember(Context *ctx, int argc, term argv[]);
+static term nif_lists_member(Context *ctx, int argc, term argv[]);
 static term nif_maps_from_keys(Context *ctx, int argc, term argv[]);
 static term nif_maps_next(Context *ctx, int argc, term argv[]);
 static term nif_unicode_characters_to_list(Context *ctx, int argc, term argv[]);
@@ -764,6 +768,22 @@ static const struct Nif erlang_lists_subtract_nif = {
     .base.type = NIFFunctionType,
     .nif_ptr = nif_erlang_lists_subtract
 };
+static const struct Nif lists_member_nif = {
+    .base.type = NIFFunctionType,
+    .nif_ptr = nif_lists_member
+};
+static const struct Nif lists_keymember_nif = {
+    .base.type = NIFFunctionType,
+    .nif_ptr = nif_lists_keymember
+};
+static const struct Nif lists_keyfind_nif = {
+    .base.type = NIFFunctionType,
+    .nif_ptr = nif_lists_keyfind
+};
+static const struct Nif list_to_bitstring_nif = {
+    .base.type = NIFFunctionType,
+    .nif_ptr = nif_erlang_list_to_bitstring_1
+};
 static const struct Nif zlib_compress_nif = {
     .base.type = NIFFunctionType,
     .nif_ptr = nif_zlib_compress_1
@@ -5824,6 +5844,97 @@ static term nif_erlang_lists_subtract(Context *ctx, int argc, term argv[])
     return result;
 }
 
+static term nif_lists_member(Context *ctx, int argc, term argv[])
+{
+    UNUSED(argc)
+    term elem = argv[0];
+    term list = argv[1];
+
+    while (term_is_nonempty_list(list)) {
+        term head = term_get_list_head(list);
+
+        TermCompareResult cmp_result = term_compare(head, elem, TermCompareExact, ctx->global);
+
+        if (cmp_result == TermEquals) {
+            return TRUE_ATOM;
+        }
+
+        if (UNLIKELY(cmp_result == TermCompareMemoryAllocFail)) {
+            RAISE_ERROR(OUT_OF_MEMORY_ATOM);
+        }
+
+        list = term_get_list_tail(list);
+    }
+
+    VALIDATE_VALUE(list, term_is_nil);
+
+    return FALSE_ATOM;
+}
+
+static term nif_lists_keymember(Context *ctx, int argc, term argv[])
+{
+    term result = nif_lists_keyfind(ctx, argc, argv);
+    if (UNLIKELY(term_is_invalid_term(result))) {
+        return result;
+    }
+    return result == FALSE_ATOM ? FALSE_ATOM : TRUE_ATOM;
+}
+
+static term nif_lists_keyfind(Context *ctx, int argc, term argv[])
+{
+    UNUSED(argc)
+    term key = argv[0];
+    term n = argv[1];
+    term tuple_list = argv[2];
+
+    VALIDATE_VALUE(n, term_is_integer);
+
+    avm_int_t n_pos = term_to_int(n);
+
+    if (n_pos <= 0) {
+        RAISE_ERROR(BADARG_ATOM);
+    }
+
+    while (term_is_nonempty_list(tuple_list)) {
+        term tuple = term_get_list_head(tuple_list);
+
+        if (!term_is_tuple(tuple)) {
+            tuple_list = term_get_list_tail(tuple_list);
+            continue;
+        }
+
+        int tuple_size = term_get_tuple_arity(tuple);
+
+        if (n_pos > tuple_size) {
+            tuple_list = term_get_list_tail(tuple_list);
+            continue;
+        }
+
+        term nth_element = term_get_tuple_element(tuple, n_pos - 1);
+
+        TermCompareResult cmp_result = term_compare(nth_element, key, TermCompareExact, ctx->global);
+
+        if (cmp_result == TermEquals) {
+            return tuple;
+        }
+        if (UNLIKELY(cmp_result == TermCompareMemoryAllocFail)) {
+            RAISE_ERROR(OUT_OF_MEMORY_ATOM);
+        }
+
+        tuple_list = term_get_list_tail(tuple_list);
+    }
+
+    VALIDATE_VALUE(tuple_list, term_is_nil);
+
+    return FALSE_ATOM;
+}
+
+static term nif_erlang_list_to_bitstring_1(Context *ctx, int argc, term argv[])
+{
+    //  TODO: implement proper list_to_bitstring function when the bitstrings are supported
+    return nif_erlang_list_to_binary_1(ctx, argc, argv);
+}
+
 #ifdef WITH_ZLIB
 static term nif_zlib_compress_1(Context *ctx, int argc, term argv[])
 {

src/libAtomVM/nifs.gperf

@@ -140,6 +140,7 @@ erlang:dist_ctrl_get_data/1, &dist_ctrl_get_data_nif
 erlang:dist_ctrl_put_data/2, &dist_ctrl_put_data_nif
 erlang:module_loaded/1,&module_loaded_nif
 erlang:nif_error/1,&nif_error_nif
+erlang:list_to_bitstring/1, &list_to_bitstring_nif
 erts_debug:flat_size/1, &flat_size_nif
 ets:new/2, &ets_new_nif
 ets:insert/2, &ets_insert_nif
@@ -180,6 +181,9 @@ base64:encode/1, &base64_encode_nif
 base64:decode/1, &base64_decode_nif
 base64:encode_to_string/1, &base64_encode_to_string_nif
 base64:decode_to_string/1, &base64_decode_to_string_nif
+lists:keyfind/3, &lists_keyfind_nif
+lists:keymember/3, &lists_keymember_nif
+lists:member/2, &lists_member_nif
 lists:reverse/1, &lists_reverse_nif
 lists:reverse/2, &lists_reverse_nif
 maps:from_keys/2, &maps_from_keys_nif

tests/erlang_tests/CMakeLists.txt

@@ -551,6 +551,11 @@ compile_assembler(test_op_bs_start_match_asm)
 compile_erlang(test_op_bs_create_bin)
 compile_assembler(test_op_bs_create_bin_asm)
 
+compile_erlang(test_list_to_bitstring)
+compile_erlang(test_lists_member)
+compile_erlang(test_lists_keymember)
+compile_erlang(test_lists_keyfind)
+
 if(Erlang_VERSION VERSION_GREATER_EQUAL "23")
     set(OTP23_OR_GREATER_TESTS
         test_op_bs_start_match_asm.beam
@@ -1070,6 +1075,12 @@ add_custom_target(erlang_test_modules DEPENDS
     test_ets.beam
     test_node.beam
 
+
+    test_list_to_bitstring.beam
+    test_lists_member.beam
+    test_lists_keymember.beam
+    test_lists_keyfind.beam
+
     test_op_bs_start_match.beam
     test_op_bs_create_bin.beam
 

tests/erlang_tests/test_list_to_bitstring.erl

@@ -0,0 +1,75 @@
+%
+% This file is part of AtomVM.
+%
+% Copyright 2025 Franciszek Kubis <franciszek.kubis@swmansion.com>
+%
+% Licensed under the Apache License, Version 2.0 (the "License");
+% you may not use this file except in compliance with the License.
+% You may obtain a copy of the License at
+%
+%    http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS,
+% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+% See the License for the specific language governing permissions and
+% limitations under the License.
+%
+% SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+%
+
+-module(test_list_to_bitstring).
+
+-export([start/0, concat/2, concat2/2, compare_bin/3, id/1]).
+
+start() ->
+    ok = test_concat(),
+    ok = test_iolist(),
+    ok = test_empty_list_to_binary(),
+    0.
+
+test_concat() ->
+    Bin = concat("Hello", "world"),
+    Bin2 = concat2("", ""),
+    CompRes1 = compare_bin(Bin, <<"Hello world">>) - compare_bin(Bin, <<"HelloXworld">>),
+    1 = CompRes1 + byte_size(Bin2) + invalid(42),
+    ok.
+
+test_iolist() ->
+    <<"Hello world">> = list_to_bitstring(?MODULE:id([<<"Hello ">>, [<<"wor">>, [$l, $d]]])),
+    ok.
+
+test_empty_list_to_binary() ->
+    <<"">> = erlang:list_to_bitstring(?MODULE:id([])),
+    ok.
+
+concat(A, B) ->
+    list_to_bitstring(?MODULE:id(A ++ " " ++ B)).
+
+concat2(A, B) ->
+    list_to_bitstring(?MODULE:id(A ++ B)).
+
+invalid(A) ->
+    try list_to_bitstring(?MODULE:id(A)) of
+        Any -> byte_size(Any)
+    catch
+        error:badarg -> 0;
+        _:_ -> 1000
+    end.
+
+compare_bin(Bin1, Bin2) ->
+    compare_bin(Bin1, Bin2, byte_size(Bin1) - 1).
+
+compare_bin(_Bin1, _Bin2, -1) ->
+    1;
+compare_bin(Bin1, Bin2, Index) ->
+    B1 = binary:at(Bin1, Index),
+    case binary:at(Bin2, Index) of
+        B1 ->
+            compare_bin(Bin1, Bin2, Index - 1);
+        _Any ->
+            0
+    end.
+
+id(X) ->
+    X.