Function Composition

Implement the function composition by C++ 20.

Part1. Project function

• nothing
• identity
• defaultTo
• always

Part2. Function composition

• gather: transform a function that takes a tuple into a function that takes multiple
• spread: tranform a function that takes multiple arguments into a function that takes a tuple
• reverse: reverse the order of the arguments of a function
• partial: left partial application
• rightPartial: right partial application
• curry: curried the function
• tap: execute a function and return the input
• alt: execute two functions and return the value which is not empty
• tryCatch: execute a function and catch the exception
• seq: execute a list of functions in sequence
• converge: apply the every value to the forker functions and gather the output to the joiner function
• map: apply the function to every element of the input
• useWith: scatter the input to the functions and gather the output
• reduce: the init value is the first argument, the second argument is the input of the function
• compose: put the input to the last function and put the output to the last second function, until the first function

Reference

函数式编程中的组合子-SegmentFault