v0.2.0

This update mainly brings bug fixes from v0.1.

What's new?

• You can now pass in custom classes into Parser.evaluate
• Constants are now precise to around 30 places.
• New constants (phi, tau)

More precise builtin functions

v0.2 changes the way some builtin functions are processed
for boosts on both performance and precision.

• sqrt now uses Decimal.sqrt
• log10 now uses Decimal.log10
• ln now uses Decimal.ln
• cbrt now uses input ** expr.one_third
• sin now uses expr.sin
• cos now uses expr.cos

Bug fixes

• Fixed unary minus interfering with implicit multiplication.
  • in v0.1: 5-3 = -15
  • in v0.2: 5-3 = 2

Miscellaneous

• Many functions now have positional-only arguments for slight performance boosts
  • This drops support for Python 3.7
• Messages retrieved from ParsingError.friendly are now much more descriptive.