Question

the exercise 1.6 in "structure and interpretation of computer programs" goes into a infinite loop. Any ideas?

Answer 1

as i use the "new-if" provided in this exercise instead of "if" ，the "sqrt-iter" goes into infinite loop. when i print the "guess" ， it print the right answer again and again. i can't figure out why. Help~~

Answer 2

Thats because of applicative avaluation method. In this case all arguments of new-if should be evaluated which leads to infinite evaluation of sqrt-iter.

Answer 3

thank you :-) As the book says "the interpreter first evaluates the operator and operands and then applies the resulting procedure to the resulting arguments". :P