Radek Szymczyszyn erszcz

Peter Thiel's CS183: Startup - Class 1 Notes Essay

Here is an essay version of my class notes from Class 1 of CS183: Startup. Errors and omissions are my own. Credit for good stuff is Peter’s entirely.

CS183: Startup—Notes Essay—The Challenge of the Future

Purpose and Preamble

Let's set the stage - we have a project with a source file under a subdir of src/. When we compile it the first time, everything looks good - the code returns the value defined by the macro:

$ cd /tmp
$ git clone https://github.com/erszcz/rebar_src_not_recompiled.git src_not_recompiled
$ cd src_not_recompiled
$ rg -C1 MACRO src/
src/subdir/m.erl

These are tests results of running EDoc from erlang/otp#2803 over all OTP and more than 20 top Hex.pm Erlang libraries.

See https://github.com/erszcz/non-otp-libraries and https://github.com/erszcz/otp/blob/edoc-chunk-support/lib/edoc/test/test_libs.sh for the tools.

Use test_libs.sh like this - see the script for more details:

VERBOSE=no LIB_DIR=/Users/erszcz/work/erlang/non-otp-libraries/_build/default/lib ERL_LIBS=/Users/erszcz/work/erlang/non-otp-libraries/_build/default/lib ERL_TOP=/Users/erszcz/work/erlang/otp EDOC=~/work/erlang/build.otp/lib/erlang/lib/edoc-0.12/bin/edoc ./test/test_libs.sh | tee non-otp-libs.log

	iex([email protected])16> Oban.check_queue(queue: "amazon_textract_reply")iex(mynode-a@127.
	%{
	name: "Oban",
	node: "[email protected]",
	running: [],
	queue: "amazon_textract_reply",
	started_at: ~U[2025-10-23 10:55:30.382229Z],
	global_limit: nil,
	local_limit: 100,
	uuid: "019a10b5-a24e-7a23-9216-825da58bda50",

	$ make -j10 tests
	test/check_name_clashes.sh
	mkdir -p "test_data"
	erlc +debug_info -o test_data test/known_problems/should_fail/arith_op.erl test/known_problems/should_fail/exhaustive_argumentwise.erl test/known_problems/should_fail/exhaustive_map_variants.erl test/known_problems/should_fail/exhaustive_remote_map_variants.erl test/known_problems/should_fail/guard_should_fail.erl test/known_problems/should_fail/infer_any_pattern.erl test/known_problems/should_fail/intersection_with_any_should_fail.erl test/known_problems/should_fail/lambda_wrong_args.erl test/known_problems/should_fail/map_refinement_fancy.erl test/known_problems/should_fail/poly_lists_map_should_fail.erl test/known_problems/should_fail/refine_ty_vars.erl test/known_problems/should_fail/rigid_type_variables_fail.erl test/known_problems/should_fail/sample.erl test/known_problems/should_fail/tuple_union_arg.erl test/known_problems/should_pass/any_doesnt_have_type_none_should_pass.erl test/known_problems/should_pass/arith_op_arg_types.erl test/kn

	$ make -j10 tests
	test/check_name_clashes.sh
	mkdir -p "test_data"
	erlc +debug_info -o test_data test/known_problems/should_fail/arith_op.erl test/known_problems/should_fail/exhaustive_argumentwise.erl test/known_problems/should_fail/exhaustive_map_variants.erl test/known_problems/should_fail/exhaustive_remote_map_variants.erl test/known_problems/should_fail/guard_should_fail.erl test/known_problems/should_fail/infer_any_pattern.erl test/known_problems/should_fail/intersection_with_any_should_fail.erl test/known_problems/should_fail/lambda_wrong_args.erl test/known_problems/should_fail/map_refinement_fancy.erl test/known_problems/should_fail/poly_lists_map_should_fail.erl test/known_problems/should_fail/refine_ty_vars.erl test/known_problems/should_fail/rigid_type_variables_fail.erl test/known_problems/should_fail/sample.erl test/known_problems/should_fail/tuple_union_arg.erl test/known_problems/should_pass/any_doesnt_have_type_none_should_pass.erl test/known_problems/should_pass/arith_op_arg_types.erl test/kn

	Gradualizer v0.1.3-150-gef2dbb7
	_build/default/lib/aoc_erlang/ebin//aoc2019_day03.beam: Nonexhaustive patterns on line 35 at column 1
	Example values which are not covered:
	[]
	_build/default/lib/aoc_erlang/ebin//aoc2019_day03.beam: The function call on line 62 at column 9 is expected to have type [35m[T, ...][0m but it has type [35m[B][0m

	map_smallest(Fun, List) ->
	lists:min([36mlists:map(Fun, List)[0m).
	[36m^^^^^^^^^^^^^^^^^^^^[0m

	FROM vectorized/redpanda:v21.10.2

	USER root

	RUN apt-get update \
	&& apt-get install -y build-essential gcc g++ libcap2-bin \
	&& apt-get clean \
	&& rm -rf /var/cache/apt/archives

	COPY sched.cc sched.cc

	Last login: Tue Mar 30 17:45:28 on ttys027
	11:13:23 erszcz @ x6 : ~
	$ cd work/josefs/gradualizer/
	11:13:49 erszcz @ x6 : ~/work/josefs/gradualizer (record-field-zip-fix)
	$ asdf local erlang 24.0-rc1
	11:14:13 erszcz @ x6 : ~/work/josefs/gradualizer (record-field-zip-fix %)
	$ cat > rebar.config
	{edoc_opts, [{doclet, edoc_doclet_chunks},
	> {layout, edoc_layout_chunks},
	> {preprocess, true},

	*.beam
	*.erltypes