// Jensen's device in Clipper (or Harbour)
//    A fairly direct translation of the Algol 60
// John M Skelton 11-Feb-2012

function main()
local i
? transform(sum(@i, 1, 100, {|| 1 / i}), "##.###############")
   // @ is the quite rarely used pass by ref, {|| ...} is a
   // code block (an anonymous function, here without arguments)
   // The @i makes it clear that something unusual is occurring;
   // a called function which modifies a parameter is commonly
   // poor design!
return 0

function sum(i, lo, hi, bFunc)
local temp := 0
for i = lo to hi
   temp += eval(bFunc)
next i
return temp