Design Considerations

Design considerations of FuPy:

• Stay close to the mathematical theory of functional programming

  • many operators are uncurried functions

• Allow interoperability with “normal” Python

  • use readable identifiers

  • auto (un)packing of function arguments

• Printable functions, including lambda expressions

• Traceable evaluation

• Lazy evaluation

Functionality:

• Basic Types: Empty, Unit, Either, Both, Func

• Infix function combinators (@, |, &, +, *), and functions like id_, const, guard

• Operator sections

• Fixpoint types and fixpoint values, with their catamorphisms and anamorphisms

Tensions

• Mathematical theory of FP and its notation and terminology

  • functions take only one argument

  • prefers uncurried operators

  • predefined function combinators (in particular, split and case)

• Python notation and terminology

  • no/multi-argument functions

• Haskell notation and terminology

  • functions take only one argument

  • prefers curried operators

  • implicit functors

• LaTeX macro names