try improving string validation

[samuelcolvin]

WIP/experiment

[codecov-commenter]

Codecov Report

Merging #622 (cc03e7c) into int-validation (6374333) will decrease coverage by 0.07%.
The diff coverage is 100.00%.

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Additional details and impacted files

@@                Coverage Diff                 @@
##           int-validation     #622      +/-   ##
==================================================
- Coverage           94.03%   93.96%   -0.07%     
==================================================
  Files                  98       98              
  Lines               13286    13290       +4     
  Branches               25       25              
==================================================
- Hits                12493    12488       -5     
- Misses                787      796       +9     
  Partials                6        6              

Impacted Files	Coverage Δ
src/validators/typed_dict.rs	97.29% <ø> (ø)
src/input/input_python.rs	98.37% <100.00%> (-0.01%)	⬇️
src/input/return_enums.rs	89.07% <100.00%> (+0.11%)	⬆️
src/validators/arguments.rs	100.00% <100.00%> (ø)
src/validators/dataclass.rs	98.24% <100.00%> (ø)
src/validators/model_fields.rs	98.73% <100.00%> (ø)
src/validators/string.rs	94.69% <100.00%> (ø)

... and 1 file with indirect coverage changes

---

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[codspeed-hq]

CodSpeed Performance Report

Merging #622 str-validation (cc03e7c) will not alter performances.

Summary

🔥 21 improvements
❌ 0 regressions
✅ 98 untouched benchmarks

🆕 1 new benchmarks
⁉️ 0 dropped benchmarks

Benchmarks breakdown

	Benchmark	int-validation	str-validation	Change
🔥	test_complete_core_strict	1.6 ms	1.4 ms	14.35%
🔥	test_complete_core_error	8.6 ms	7.5 ms	13.12%
🔥	test_complete_core_isinstance	8.5 ms	7.3 ms	13.98%
🔥	test_core_python_fs	392.7 µs	339.3 µs	13.61%
🔥	test_list_of_ints_core_py	8.5 ms	2.6 ms	69.10%
🔥	test_set_of_ints_core	10.5 ms	3.8 ms	63.44%
🔥	test_set_of_ints_core_duplicates	8.2 ms	2.3 ms	72.23%
🔥	test_set_of_ints_core_length	10.6 ms	3.9 ms	62.94%
🔥	test_frozenset_of_ints_core	2.4 ms	1.3 ms	45.16%
🔥	test_frozenset_of_ints_duplicates_core	1,251.2 µs	995.5 µs	20.43%
🔥	test_dict_of_ints_core	12.6 ms	6 ms	52.47%
🔥	test_many_models_core_dict	5.6 ms	4.9 ms	11.10%
🔥	test_list_of_nullable_core	1,121.4 µs	626.1 µs	44.17%
🔥	test_positional_tuple	36.9 µs	25.3 µs	31.56%
🔥	test_variable_tuple	37.4 µs	25.9 µs	30.63%
🔥	test_int_error	78.1 µs	68.4 µs	12.39%
🔥	test_definition_in_tree	28.8 ms	5.6 ms	80.65%
🔥	test_definition_out_of_tree	32.6 ms	9.4 ms	71.17%
🔥	test_model_instance	57 µs	46.8 µs	17.93%
🔥	test_model_instance_abc	60.7 µs	47.7 µs	21.39%
🔥	test_core_root_model	119.6 µs	94.4 µs	21.08%
🆕	test_strict_int	N/A	15.3 µs	N/A

[samuelcolvin]

replaced b