Functional programming jargon in plain English

mjburgess 11 days ago | next [–]

These definitions don’t really give you the idea, rather often just code examples..
“The ideas”, in my view:


Monoid	=	units that can be joined together
Functor	=	context for running a single-input function
Applicative	=	context for multi-input functions
Monad	=	context for sequence-dependent operations
Lifting	=	converting from one context to another
Sum type	=	something is either A or B or C…
Product type	=	a record
	=	something is both A and B and C
Partial application	=	defaulting an argument to a function
Currying	=	passing some arguments later
	=	rephrasing a function to return a functions of n-1 arguments when given 1, st. the final function will compute the desired result
EDIT: Context	=	compiler information that changes how the program will be interpreted (, executed, compiled,…)
Eg., context	=	run in the future, run across a list, redirect the i/o, …

— Functional programming jargon in plain English

— Hacker News

Currying and partial function application are often conflated. One of the significant differences between the two is that a call to a partially applied function returns the result right away, not another function down the currying chain; this distinction can be illustrated clearly for functions whose arity is greater than two.

Partial application can be seen as evaluating a curried function at a fixed point, e.g. given $\displaystyle{f\colon (X\times Y\times Z)\to N}$ and $\displaystyle{a\in X}$ then