Stack overflow with recursive function

Question

I'm trying to make a recursive function where i pass in a integer and a list. I want to append a certain number of "-" (dashes) to the list if the length of the list is less than the integer as follows:

let rec dashes (longest, l1) =  
    if length l1 = longest then l1 
    else ["-"]@l1@dashes(longest,l1);;

However I get a stack overflow and I'm not sure why.

Answer 1

您对dashes递归调用将通过原始的l1参数传递，因此列表长度永远不会增加，并且终止条件仍为false。