[Haskell-cafe] Lazy evaluation from "Why Functional programming matters"

Hi All, I was going through the paper's "lazy evaluation" section where the square root example is given. It occurred to me that one could implement it in a modular way with just higher order functions (without the need for lazy evaluation that is). function f (within, eps, next, a0){ while(true){ a1=next(a0); if(within(a0,a1,eps)return a0; a0=a1; } } Is this not the case? -- Regards, Kashyap