feat: improving performance

[TIMMLOPK]

Description

65

1. use spread instead of Object.assign()
2. use for...in instead of foreach
3. use stack to replace .flat()

Although this pr doesn't make tv faster than cva, it is improved

Additional context

Base on the #65 benchmark tests

Before

CVA x 854,053 ops/sec ±3.37% (85 runs sampled)
CVA with tailwind-merge x 459,752 ops/sec ±2.91% (87 runs sampled)
TV with slots x 80,733 ops/sec ±5.49% (93 runs sampled)
TV without slots x 95,664 ops/sec ±0.72% (91 runs sampled)
Fastest is CVA

Now

CVA x 897,001 ops/sec ±1.46% (90 runs sampled)
CVA with tailwind-merge x 471,939 ops/sec ±1.20% (93 runs sampled)
TV with slots x 151,139 ops/sec ±1.67% (93 runs sampled)
TV without slots x 172,622 ops/sec ±0.72% (92 runs sampled)
Fastest is CVA

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What is the purpose of this pull request?

• [ ] Bug fix
• [ ] New Feature
• [ ] Documentation update
• [X] Other

Before submitting the PR, please make sure you do the following

• [x] Read the Contributing Guidelines.
• [x] Follow the Style Guide.
• [x] Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• [x] Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).

[jrgarciadev]

Hey @TIMMLOPK thank you!, please check the tests, almost all of them are failing

[TIMMLOPK]

Fixed, I would update the benchmark later

[TIMMLOPK]

New benchmark runs on my PC(Windows 11, 4 core, node v18.15.0)

Before

CVA x 854,053 ops/sec ±3.37% (85 runs sampled)
CVA with tailwind-merge x 459,752 ops/sec ±2.91% (87 runs sampled)
TV with slots x 80,733 ops/sec ±5.49% (93 runs sampled)
TV without slots x 95,664 ops/sec ±0.72% (91 runs sampled)
Fastest is CVA

Now

CVA x 897,001 ops/sec ±1.46% (90 runs sampled)
CVA with tailwind-merge x 471,939 ops/sec ±1.20% (93 runs sampled)
TV with slots x 151,139 ops/sec ±1.67% (93 runs sampled)
TV without slots x 172,622 ops/sec ±0.72% (92 runs sampled)
Fastest is CVA

[Handfish]

@TIMMLOPK @jrgarciadev I made a pull request to @TIMMLOPK branch as I worked off his progress to code golf this forward a little bit. I found that flattening the arrays with recursion squeezed out some more ops/sec.