COMP40...int main(){char *my_string; int length = get_string(my_string); printf(“We have string %s...

$: COMP40...int main(){char *my_string; int length = get_string(my_string); printf(“We have string %s of size %d”, my_string, length);} int get_string(char *sp) {sp = malloc ...$
COMP40More on Abstract Data Types

This generalization is known as universal polymorphism

List_push(List_T list, void *v)

void *v = s;

void *v = c;

void *v = p;

void *v = l;

/* Declare the type Table_T to be a struct pointer */typedef struct T *T;

/* Define Table_new to return the struct pointer */T Table_new(...);

#define T Table_T

struct Car {char *brand; int year;}; typedef struct Car Car;

List_T mylist = List_list(NULL); Car *retrieved_car;Car mycar = {"ford", 2000};

mylist = List_push(mylist, &mycar); mylist = List_pop(mylist, (void **)&retrieved_car);

List_free(&mylist);

void double(int n) {n = n * 2;

}

int x = 3;double(x);printf(“x = %d\n”, x);

void double(int *n) {*n = *n * 2;

}

int x = 3;double(&x);printf(“x = %d\n”, x);

int main(){ char *my_string; int length = get_string(my_string); printf(“We have string %s of size %d”, my_string, length);

}

int get_string(char *sp) { sp = malloc(...); /* Set *sp, *(sp+1), … */ return strlen(sp);}

/* Allocate a chunk of memory and read a string into it. Return both a pointer to the string and its length. */

int main(){ char *my_string; int length = get_string(my_string) ; printf(“We have string %s of size %d”, my_string, length);

}


my_string

length = ?

sp



}


my_string

length = ?

sp

h e l l o \0



}


my_string

length = ?

sp

h e l l o \0

length = 5

my_string/* Allocate a chunk of memory and read a string into it. Return both a pointer to the string and its length. */

int main(){ char *my_string; int length = get_string( &my_string); printf(“We have string %s of size %d”, my_string, length);

}

int get_string(char **sp_p) { *sp_p = malloc(...); /* Set **sp_p, *(*sp_p + 1), … */ return strlen(*sp_p);}

my_string

length = ?

sp_p


int main(){ char *my_string; int length = get_string( &my_string); printf(“We have string %s of size %d”, my_string, length);

}

int get_string(char **sp_p) { *sp_p = malloc(...); /* Set **sp_p, *(*sp_p + 1), … */ return strlen(*sp_p);}

my_string

length = ?

sp_p

h e l l o \0

length = 5


void print_hi() {printf(“%s\n”, “hi”);

}void print_no() {

printf(“%s\n”, “no”);}void print_yes() {

printf(“%s\n”, “yes”);}

void print_string(char *s) {printf(“%s\n”, s);

}

void List_push_int(List_int *l, int x) { /* Add in new integer element */}void List_push_char(List_char *l, char x) { /* Add in new character element */}

void List_push(List_T *l, void *x) { /* Add in new element */}

int find_min(int[] nums, int size) { int min = nums[0]; for (int i = 1; i < size; i++) { if (min > nums[i]) min = nums[i]; } return min;}

int find_max(int[] nums, int size) { int max = nums[0]; for (int i = 1; i < size; i++) { if (max < nums[i]) max = nums[i]; } return max;}

T f(int[] nums, int size, <func>) { T cl; for (int i = 0; i < size; i++) { cl = <func>(nums[i], cl); } return cl;}

void f(int[] nums, int size, <func>) { for (int i = 0; i < size; i++) { <func>(nums[i]); } }

int x = 77;int *p = &x;

void f() {printf(“Hello”);

} f<func> *fp;fp = f; pfp();

int f(int x); //function declaration (prototype)

int *g(int x); //function returning an int *int (*h)(int x); //function pointer declaration

int f(int x) {return x + 1;

}

int main() {//& and * are optionalh = &f;printf(“%d\n”, (*h)(4));

}

int f(int x); //function declaration (prototype)

int *g(int x); //function returning an int *int (*h)(int x); //function pointer declaration

int f(int x) {return x + 1;

}

int main() {//& and * are optionalh = f;printf(“%d\n”, h(4));

}

int cube(int n) { return n * n * n;}int func_app(int n, int f(int x)) { return f(n);}int main() { int (*func_ptr)(int x); //parameters may be named func_ptr = cube; printf(“%d\n”, cube(4)); printf(“%d\n”, func_ptr(4)); printf(“%d\n”, func_app(4, func_ptr));}

int digits[30];int i;

for (i = 0; i < 30; i++) { digits[i] = i;}

for (i = 0; i < 30; i++) { digits[i] = f(i);}

for (i = 0; i < 30; i += 2) { digits[i] = g(i);}

✓

void f(void **x, void *cl) { //perform computation on *x}

List_T list = List_list(...);

//populate the list

List_map(list, f, NULL);

✓

✓

✓

void f(void **x, void *cl) { (void) cl; int *elem = *x; *elem += 10;}

int *digits = malloc(3 * sizeof(*digits));

for (int i = 0; i < 3; i++) {*(digits + i) = i;

}List_T list = List_list( digits,

(void *)(digits+1), (void *)(digits+2), NULL);

List_map(list, f, NULL);

void f(void **x, void *cl) { int *elem = *x; int *accum_p = cl; *elem += 10; *accum_p += *elem;}

int *digits = malloc(3 * sizeof(*digits));int accum = 0;for (int i = 0; i < 3; i++) {

*(digits + i) = i;}List_T list = List_list( digits,


List_map(list, f, &accum);

void f(void **x, void *cl) { int *elem = *x; int *accum_p = cl; *elem += 10; *accum_p += *elem;}int accum = 0;List_T list = List_list(...);List_map(list, f, &accum);

0 1 2

0


10 1 2

10


10 11 2

21


10 11 12

33

void f(void **x, void *cl) { int *elem = *x; int *accum_p = cl; *elem += 10; *accum_p += *elem;}

int *digits = malloc(3 * sizeof(*digits));int accum = 0;for (int i = 0; i < 3; i++) {

*(digits + i) = i;}List_T list = List_list( digits,


List_map(list, f, &accum);

10 11 12

1011

12

COMP40...int main(){char *my_string; int length = get_string(my_string); printf(“We have string %s...

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