[Haskell-cafe] Efficiency of passing function arguments

[Henning Thielemann]

On Sat, 4 Apr 2020, KS wrote:

> and we want to pass doc to a function, we should ideally hope that doc 
> is not getting duplicated when passing it as an argument.

In Haskell, values are immutable and thus there is no need to copy. Values 
and parameters are always references. Due to laziness a value references a 
union. This union is in the beginning a generating function and once the 
value gots evaluated, it is the computed value.