B3: Numbers #41

Numbers are the most used value objects and the base that later families build on: Port is an Int with two bounds, CvssScore and Money reuse the decimal parsing and places, and Percentage.of() scales Money. This block rebuilds them on the 1.0 core in one module, pyvalueobjects/numeric.py: an abstract Numeric base whose operators keep the left operand's concrete type and re-validate every result, the Int, Float and DecimalNumber families (each with its four sign variants as one-line Bounds declarations), and Percentage. Text goes through the core's ASCII literal() grammars, so from_str is exact for big integers and never accepts '1_000', '١٢', 'nan' or '1e3' for an int. Every Decimal operation runs in the library's own DECIMAL_CONTEXT, never in the caller's thread-local context. The last commit exports the new classes from the package root and deletes the 0.x number modules and their unittest suites, together with the Nullable* number classes.

Fixes items C09, C10, C11, C12, C13, C16, X02, X03, X04 and C14/C46/C54 of #34.

Tasks

• Add Numeric and the Int family (5 classes), with samples and tests/test_numeric.py. (ebf9872, cd2c88e, 750b31a, b141674, 7a8a34a)
• Add the Float family (5 classes). (599951d, 1031aaa, 8953619)
• Add DECIMAL_CONTEXT, quantize_exact and the DecimalNumber family (5 classes, with places). (60e463f, f349545, 06080e9, 3b6593b)
• Add Percentage with ratio and of. (435f4b1)
• Export the new numbers. Delete the legacy numbers/ modules and tests; _legacy/numbers/int.py survives because the legacy list tests import it. (0d135a8, 2aaaab0)

Related bugs

• Bugs: numeric parsing and validation (0.28.1) #34 C09: Int.from_str parses through float and silently changes integers above 2**53.
• Bugs: numeric parsing and validation (0.28.1) #34 C10: Int.from_str accepts non-integer strings that round or underflow to an integer ('0.99999999999999999', '1e-400').
• Bugs: numeric parsing and validation (0.28.1) #34 C11: Int.from_str rejects large integer strings that the constructor accepts ('1' * 400).
• Bugs: numeric parsing and validation (0.28.1) #34 C12: Int.from_str has no input type check (bool, bytes, int, float, Decimal, IntEnum).
• Bugs: numeric parsing and validation (0.28.1) #34 C13: Int.from_str/from_float replace subclass validation errors with misleading format messages.
• Bugs: numeric parsing and validation (0.28.1) #34 C16: bounded int constructors and Int.from_float(inf/nan) report misleading messages.
• Bugs: numeric parsing and validation (0.28.1) #34 X02: Int.from_str/Float.from_str accept underscore-grouped, exponent (for ints) and non-ASCII-digit strings.
• Bugs: numeric parsing and validation (0.28.1) #34 X03: Float.from_int silently rounds integers that are not exactly representable.
• Bugs: numeric parsing and validation (0.28.1) #34 X04: Int accepts integers whose text form then raises a plain ValueError (int max-str-digits limit).
• Bugs: numeric parsing and validation (0.28.1) #34 C14/C46/C54: the *from_str*_with_decimals tests call from_float, and the zero test passes an int to from_str, so from_str decimal handling is untested.