erldistpy/docs/etf_vectors.erl
russell@unturf.com b9fd28ca3b
phase 0 + 1: repo bones and ETF codec
Repo scaffolding (LICENSE, Makefile, pyproject.toml, README) matching
unfeed conventions. Flat package layout, ruff config, Unlicense.

ETF codec covers the subset needed for gen_call against an Elixir node:
small/int/big_int, atom_utf8 (legacy atom_ext on decode), binary, nil,
list, small/large tuple, new_pid, newer_reference. Booleans round-trip
as atoms true/false; Python None as atom nil; str encodes to utf-8
binary to match Elixir convention.

Golden vectors were generated from real Erlang term_to_binary/1 output
(generator script at docs/etf_vectors.erl). Decode tests verify wire
compatibility; round-trip tests verify encoder consistency.

make all green: 58 passed, lint clean.

Next phases tracked in docs/ROADMAP.md (EPMD, handshake, channel,
gen_call, TLS, unfeed integration).
2026-06-16 10:39:01 -04:00

47 lines
1.4 KiB
Erlang

%% Generator for the golden ETF vectors used in tests/test_etf.py.
%% Re-run when adding new test cases:
%%
%% erlc -o /tmp docs/etf_vectors.erl
%% erl -noshell -pa /tmp -eval 'etf_vectors:main([]), init:stop().'
%% cat /tmp/etf_vectors.txt
%%
-module(etf_vectors).
-export([main/1]).
main(_) ->
Terms = [
{small_int_0, 0},
{small_int_42, 42},
{small_int_255, 255},
{int_256, 256},
{int_neg_1, -1},
{int_max32, 2147483647},
{int_min32, -2147483648},
{big_pos, 9999999999999999},
{big_neg, -9999999999999999},
{atom_hello, hello},
{atom_true, true},
{atom_false, false},
{atom_nil, nil},
{atom_unicode, 'привет'},
{binary_empty, <<>>},
{binary_hi, <<"hi">>},
{binary_utf8, <<"héllo"/utf8>>},
{tuple_empty, {}},
{tuple_pair, {ok, <<"value">>}},
{tuple_triple, {1, 2, 3}},
{list_empty, []},
{list_ints, [1, 2, 3]},
{list_mixed, [hello, <<"world">>, 42]},
{nested, {gen_call, [{node, 'wallet@cammy'}], {get_balance, xmr}}}
],
Out = [
io_lib:format("~s|~s~n", [atom_to_list(N), bin_to_hex(term_to_binary(T))])
|| {N, T} <- Terms
],
ok = file:write_file("/tmp/etf_vectors.txt", iolist_to_binary(Out)).
bin_to_hex(B) ->
<< <<(hex(N div 16)), (hex(N rem 16))>> || <<N>> <= B >>.
hex(N) when N < 10 -> $0 + N;
hex(N) -> $a + N - 10.