Funarg Problem - Downwards Funarg Problem

Downwards Funarg Problem

A downwards funarg may also refer to a function's state when that function is not actually executing. However, because, by definition, the existence of a downwards funarg is contained in the execution of the function that creates it, the activation record for the function can usually still be stored on the stack. Nonetheless, the existence of downwards funargs implies a tree structure of closures and activation records that can complicate human and machine reasoning about the program state.

The downwards funarg problem complicates the efficient compilation of tail recursion and code written in continuation-passing style. In these special cases, the intent of the programmer is (usually) that the function run in limited stack space, so the "faster" behavior may actually be undesirable.