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To see how declarations appear in the body of a function, consider the following example, which uses Newton's method to calculate square roots :2(Adapted from section 1.1.8 of Structure and Interpretation of Computer Programs.):
| Code Block | ||||
|---|---|---|---|---|
| ||||
sqrt = function(x) {
average = function(x,y) { (x + y) / 2 };
good_enough = function(guess, x) {
v = (guess * guess) - x;
v < 0.01 && v > -0.01
};
improve = function(guess, x) {
average(guess, (x / guess))
};
sqrt_iter = function(guess, x) {
good_enough(guess, x) => guess
| sqrt_iter(improve(guess,x), x)
};
sqrt_iter(1.0, x)
} |
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