poc: fasten hook

[artemeff]

proof of concept to compile module make/2 function into something like this:

def make(params, opts) do
  with {:ok, a} <- __cast_a__(params, opts),
       {:ok, b} <- __cast_b__(params, opts) do
    {:ok, struct(ExampleFast, a: a, b: b, c: c, d: d, e: e)}
  end
end

defp __cast_a__(%{"a" => term}, opts) do
  Construct.Type.cast(:string, term, opts)
end

defp __cast_a__(%{a: term}, opts) do
  Construct.Type.cast(:string, term, opts)
end

defp __cast_a__(_, _) do
  {:error, %{a: :missing}}
end

defp __cast_b__(%{"b" => term}, opts) do
  Construct.Type.cast(:float, term, opts)
end

defp __cast_b__(%{b: term}, opts) do
  Construct.Type.cast(:float, term, opts)
end

defp __cast_b__(_, _) do
  {:error, %{b: :missing}}
end

this prevents types traversal to increase performance by almost 3 times. results from bench/struct_bench.exs

Operating System: macOS
CPU Information: Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
Number of Available Cores: 16
Available memory: 64 GB
Elixir 1.14.0
Erlang 25.0.4

Benchmark suite executing with the following configuration:
warmup: 2 s
time: 3 s
memory time: 3 s
reduction time: 3 s
parallel: 1
inputs: none specified
Estimated total run time: 22 s

Benchmarking make ...
Benchmarking make optimized ...

Name                     ips        average  deviation         median         99th %
make optimized      799.50 K        1.25 μs  ±2251.41%        1.08 μs        1.69 μs
make                300.32 K        3.33 μs   ±419.27%        2.99 μs        5.04 μs

Comparison:
make optimized      799.50 K
make                300.32 K - 2.66x slower +2.08 μs

Memory usage statistics:

Name              Memory usage
make optimized         1.12 KB
make                   3.43 KB - 3.07x memory usage +2.31 KB

**All measurements for memory usage were the same**

Reduction count statistics:

Name           Reduction count
make optimized             109
make                       362 - 3.32x reduction count +253

[coveralls]

Pull Request Test Coverage Report for Build 260d0bc00fda028425e2d03d4d37b6eb8c3aff79-PR-45

• 1 of 31 (3.23%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-7.0%) to 84.518%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
lib/construct/hooks/fasten.ex	0	30	0.0%

Totals
Change from base Build 38acc7c1eb0c6cdaa11568f7e2393dd93eb8841a:	-7.0%
Covered Lines:	333
Relevant Lines:	394

---

💛 - Coveralls

[artemeff]

Operating System: macOS
CPU Information: Apple M3 Pro
Number of Available Cores: 12
Available memory: 36 GB
Elixir 1.17.3
Erlang 27.1

Benchmark suite executing with the following configuration:
warmup: 2 s
time: 3 s
memory time: 3 s
reduction time: 3 s
parallel: 1
inputs: none specified
Estimated total run time: 22 s

Benchmarking make ...
Benchmarking make optimized ...

Name                     ips        average  deviation         median         99th %
make optimized        2.85 M      350.96 ns  ±2847.14%         333 ns         459 ns
make                  1.14 M      880.07 ns  ±1296.72%         833 ns        1125 ns

Comparison:
make optimized        2.85 M
make                  1.14 M - 2.51x slower +529.10 ns

Memory usage statistics:

Name              Memory usage
make optimized         1.01 KB
make                   3.15 KB - 3.12x memory usage +2.14 KB

**All measurements for memory usage were the same**

Reduction count statistics:

Name           Reduction count
make optimized             109
make                       362 - 3.32x reduction count +253

**All measurements for reduction count were the same**