chelseatroy

...

private void scanToken() {
    char c = advance();
    switch (c) {
      case '(': addToken(LEFT_PAREN); break;
      case ')': addToken(RIGHT_PAREN); break;
      case '{': addToken(LEFT_BRACE); break;
      case '}': addToken(RIGHT_BRACE); break;
      case ',': addToken(COMMA); break;

chelseatroy

private void scanToken(char character) {
        if (singleCharacterToken(character) != null) {
            addToken(singleCharacterToken(character));
            return;
        }

        if (isComparisonOperator(character)) {
            addComparisonOperatorTokenFor(character);
            return;
        }

chelseatroy

(define (p) (p))
 
(define (test x y)
  (if (= x 0)
      0
      y))

(test 0 (p))

chelseatroy

(define (find-smallest a b c) 
  (cond ((and (<= a b) (<= a c) a))
        ((and (<= b c) (<= b c) b))
        ((and (<= c a) (<= c b) c))
   )
)

(define (largest-squared-hypotenuse a b c) (
    cond ((= (find-smallest a b c) a) (+ (* b b) (* c c)))
         ((= (find-smallest a b c) b) (+ (* a a) (* c c)))

chelseatroy

(define (square x) (* x x))
(define (average x y)
     (/ (+ x y) 2))

(define (sqrt x)
    (define (improve guess)
        (average guess (/ x guess)))

    (define (good-enough? guess)
        (< (abs (- (square guess) x)) (* 0.000001 x)))

chelseatroy

(define (sum-n n)
    (if (= n 0)
        0
        (+ n (sum-n (- n 1)))
    )
)

(sum-n 5) ; 15

chelseatroy

(define (sum-i n)
    (define (iter n sofar)
        (if (= n 0)
            sofar
            (+ (iter (- n 1) (+ n sofar)))))
    (iter n 0)
)

(sum-i 5) ; 15

chelseatroy

  
(define (sum term a next b)
  (accumulate + 0 term a next b))

(define (product term a next b)
  (accumulate * 1 term a next b))

(define (factorial n)
  (product identity 1 inc n))

chelseatroy

(define (square x) (* x x))
(define (qb x) (* x x x))
(define (average x y)
     (/ (+ x y) 2))

(define (sq-improve guess for-value)
        (average guess (/ for-value guess)))

(define (qb-improve guess for-value)
        (/ (+(/ for-value (square guess)) (* 2 guess)) 3))

chelseatroy

; 1.41

(define (double f)
  (lambda (x) (f(f x))))

(define (add-2-to x) (+ 2 x))
(define (inc x) (+ 1 x))
(define (square x) (* x x))

((double add-2-to) 3)