Add the missing `tan` method to the Num class, implementing the tangent
trigonometric function. This fills the gap between the existing `sin` and
`cos` methods, providing a complete set of basic trigonometric operations.
- Register `num_tan` primitive in the VM core initialization
- Implement `DEF_PRIMITIVE(num_tan)` using C's `tan()` math function
- Add documentation entry for `tan` in the core library reference
Implements a new `fromString` static method on the `Num` class that attempts to parse a string as a decimal number literal using `strtod`. Returns the parsed `Num` value on success, or `null` if the string does not represent a valid number. Includes runtime validation that the argument is a string, and adds test coverage for positive, negative, zero, and decimal inputs as well as non-numeric strings.
Thorbjørn Lindeijer
Bob Nystrom
hachibu
Gavin Schulz