diff options
Diffstat (limited to 'coding-exercises/2/78')
| -rw-r--r-- | coding-exercises/2/78/complex-polar.rkt | 8 | ||||
| -rw-r--r-- | coding-exercises/2/78/complex-rectangular.rkt | 3 | ||||
| -rw-r--r-- | coding-exercises/2/78/install-complex-package.rkt | 73 | ||||
| -rw-r--r-- | coding-exercises/2/78/install-rational-package.rkt | 58 | ||||
| -rw-r--r-- | coding-exercises/2/78/scheme-number.rkt | 18 |
5 files changed, 157 insertions, 3 deletions
diff --git a/coding-exercises/2/78/complex-polar.rkt b/coding-exercises/2/78/complex-polar.rkt index 661627d..3c8cfe8 100644 --- a/coding-exercises/2/78/complex-polar.rkt +++ b/coding-exercises/2/78/complex-polar.rkt @@ -1,7 +1,8 @@ #lang racket (provide install-polar-package) +(require "../../../shared/data-directed-programming.rkt") -(define (install-polar-package) +(define (install-polar-package put) (define (magnitude z) (car z)) (define (angle z) @@ -21,4 +22,7 @@ (put 'real-part '(polar) real-part) (put 'imag-part '(polar) imag-part) (put 'magnitude '(polar) magnitude) - (put 'angle '(polar))) + (put 'angle '(polar) angle) + (put 'make-from-real-imag 'polar (lambda (x y) (typtag (make-from-real-imag x y)))) + (put 'make-from-mag-ang 'polar (lambda (r a) (typtag (make-from-mag-ang r a)))) + 'done) diff --git a/coding-exercises/2/78/complex-rectangular.rkt b/coding-exercises/2/78/complex-rectangular.rkt index 41e93b6..bbc2b8c 100644 --- a/coding-exercises/2/78/complex-rectangular.rkt +++ b/coding-exercises/2/78/complex-rectangular.rkt @@ -26,4 +26,5 @@ (put 'make-from-real-imag 'rectangular (lambda (x y) (typtag (make-from-real-imag x y)))) (put 'make-from-mag-ang 'rectangular - (lambda (r a) (typtag (make-from-mag-ang r a))))) + (lambda (r a) (typtag (make-from-mag-ang r a)))) + 'done) diff --git a/coding-exercises/2/78/install-complex-package.rkt b/coding-exercises/2/78/install-complex-package.rkt new file mode 100644 index 0000000..a656495 --- /dev/null +++ b/coding-exercises/2/78/install-complex-package.rkt @@ -0,0 +1,73 @@ +#lang racket +(provide install-complex-package) +(require "../../../shared/data-directed-programming.rkt") +(require "./complex-rectangular.rkt") +(require "./complex-polar.rkt") + + +(define (install-complex-package apply-generic get put) + ;; install and import methods + (install-rectangular-package put) + (install-polar-package put) + (define (make-from-real-imag x y) + ((get 'make-from-real-imag 'rectangular) x y)) + (define (make-from-mag-ang r a) + ((get 'make-from-mag-ang 'polar) r a)) + + (define (real-part z) + (apply-generic 'real-part z)) + (define (imag-part z) + (apply-generic 'imag-part z)) + (define (magnitude z) + (apply-generic 'magnitude z)) + (define (angle z) + (apply-generic 'angle z)) + + ;; internal + (define (add-complex z1 z2) + (make-from-real-imag (+ (real-part z1) (real-part z2)) + (+ (imag-part z1) (imag-part z2)))) + (define (sub-complex z1 z2) + (make-from-real-imag (- (real-part z1) (real-part z2)) + (- (imag-part z1) (imag-part z2)))) + (define (mul-complex z1 z2) + (make-from-mag-ang (* (magnitude z1) (magnitude z2)) + (+ (angle z1) (angle z2)))) + (define (div-complex z1 z2) + (make-from-mag-ang (/ (magnitude z1) (magnitude z2)) + (- (angle z1) (angle z2)))) + + ;; predicates (...) -> bool + (define (equ? z1 z2) + (and (equal? (real-part z1) (real-part z2)) + (equal? (imag-part z1) (imag-part z2)))) + (define (=zero? z) + (and (= (real-part z)) (= (imag-part z)))) + + ;; interface + (define (typetag z) (attach-tag 'complex z)) + (put 'real-part '(complex) real-part) + (put 'imag-part '(complex) imag-part) + (put 'magnitude '(complex) magnitude) + (put 'angle '(complex) angle) + + (put 'add '(complex complex) + (lambda (z1 z2) (typetag (add-complex z1 z2)))) + (put 'sub '(complex complex) + (lambda (z1 z2) (typetag (sub-complex z1 z2)))) + (put 'mul '(complex complex) + (lambda (z1 z2) (typetag (mul-complex z1 z2)))) + (put 'div '(complex complex) + (lambda (z1 z2) (typetag (div-complex z1 z2)))) + + (put 'equ? '(complex complex) + (lambda (z1 z2) (equ? z1 z2))) + (put '=zero? '(complex) + (lambda (z1) (=zero? z1))) + + (put 'make-from-real-imag 'complex + (lambda (x y) (typetag (make-from-real-imag x y)))) + (put 'make-from-mag-ang 'complex + (lambda (r a) (typetag (make-from-mag-ang r a)))) + 'done) + diff --git a/coding-exercises/2/78/install-rational-package.rkt b/coding-exercises/2/78/install-rational-package.rkt new file mode 100644 index 0000000..db4475e --- /dev/null +++ b/coding-exercises/2/78/install-rational-package.rkt @@ -0,0 +1,58 @@ +#lang racket +(provide install-rational-package) +(require "../../../shared/data-directed-programming.rkt") + + +(define (install-rational-package put) + ;; internal + (define (numer x) (car x)) + (define (denom x) (cdr x)) + (define (make-rat n d) + (define (sign x) + (cond + ((and (< x 0) (< d 0)) (* -1 x)) + ((and (< 0 x) (< d 0)) (* -1 x)) + (else x))) + (let ((g (gcd n d))) + (cons (sign (/ n g)) (abs (/ d g))))) + (define (add-rat x y) + (make-rat (+ (* (numer x) (denom y)) + (* (numer y) (denom x))) + (* (denom x) (denom y)))) + (define (sub-rat x y) + (make-rat (- (* (numer x) (denom y)) + (* (numer y) (denom x))) + (* (denom x) (denom y)))) + (define (mul-rat x y) + (make-rat (* (numer x) (numer y)) + (* (denom x) (denom y)))) + (define (div-rat x y) + (make-rat (* (numer x) (denom y)) + (* (denom x) (numer y)))) + + ;; predicates + (define (equ? x y) + (and (equal? (numer x) (numer y)) + (equal? (denom x) (denom y)))) + (define (=zero? x) + (equal? (numer x) 0)) + + ;; interface + (define (typetag x) (attach-tag 'rational x)) + (put 'add '(rational rational) + (lambda (x y) (typetag (add-rat x y)))) + (put 'sub '(rational rational) + (lambda (x y) (typetag (sub-rat x y)))) + (put 'mul '(rational rational) + (lambda (x y) (typetag (mul-rat x y)))) + (put 'div '(rational rational) + (lambda (x y) (typetag (div-rat x y)))) + + (put 'equ? '(rational rational) + (lambda (x y) (equ? x y))) + (put '=zero? '(rational) + (lambda (x) (=zero? x))) + + (put 'make 'rational + (lambda (x y) (typetag (make-rat x y)))) + 'done) diff --git a/coding-exercises/2/78/scheme-number.rkt b/coding-exercises/2/78/scheme-number.rkt new file mode 100644 index 0000000..fa9c0ec --- /dev/null +++ b/coding-exercises/2/78/scheme-number.rkt @@ -0,0 +1,18 @@ +#lang racket +(provide install-scheme-number-package) +(require "../../../shared/data-directed-programming.rkt") + + +(define (install-scheme-number-package put) + ;; interface part + (define (typtag x) + (attach-tag 'scheme-number x)) + + (put 'add '(scheme-number scheme-number) (lambda (x y) (typtag (+ x y)))) + (put 'sub '(scheme-number scheme-number) (lambda (x y) (typtag (- x y)))) + (put 'mul '(scheme-number scheme-number) (lambda (x y) (typtag (* x y)))) + (put 'div '(scheme-number scheme-number) (lambda (x y) (typtag (/ x y)))) + (put 'equ? '(scheme-number scheme-number) (lambda (x y) (= x y))) + (put '=zero? '(scheme-number) (lambda (x) (= 0 x))) + (put 'make 'scheme-number (lambda (x) (typtag x))) + 'done) |