C compiler with embedded metalanguage.
選択できるのは25トピックまでです。 トピックは、先頭が英数字で、英数字とダッシュ('-')を使用した35文字以内のものにしてください。
 
 
 

149 行
3.3 KiB

// This example serves to illustrate the possibility
// of adding the object aspect to C
// using the everyExternalDeclaration function.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct Symbol {
char *name;
int class, selector;
};
struct Symbol *newSymbol(char *name)
{
struct Symbol *symbol = malloc(sizeof(*symbol));
symbol->name = strdup(name);
symbol->class = 0;
symbol->selector = 0;
return symbol;
}
struct Symbol **symbols = 0;
int nSymbols = 0;
struct Symbol *intern(char *name)
{
int lo = 0;
int hi = nSymbols - 1;
while (lo <= hi ) {
int mid = (lo+hi)/2;
int cmp = strcmp(name, symbols[mid]->name);
if (cmp > 0) lo = mid + 1;
else if (cmp < 0) hi = mid - 1;
else return symbols[mid];
}
symbols = realloc(symbols, sizeof(*symbols) * ++nSymbols);
memmove(symbols + lo + 1, symbols + lo, sizeof(*symbols)*(nSymbols - lo - 1));
return symbols[lo] = newSymbol(name);
}
typedef void *(*method_t)();
void *method_dnu()
{
printf("method not found\n");
exit(1);
return 0;
}
method_t **methods = 0;
int nClasses = 0;
int nSelectors = 0;
int ensureClass(struct Symbol *symbol)
{
if (symbol->class == 0) {
if (nClasses == 0) nClasses++;
symbol->class = nClasses++;
methods = realloc(methods, sizeof(*methods)*nClasses);
methods[symbol->class] = malloc(sizeof(*methods)*nSelectors);
for (int i = 0; i<nSelectors; ++i)
methods[symbol->class][i] = method_dnu;
}
return symbol->class;
}
int ensureSelector(struct Symbol *symbol)
{
if (symbol->selector == 0) {
if (nSelectors == 0) nSelectors++;
symbol->selector = nSelectors++;
for (int i = 0; i<nClasses; ++i) {
methods[i] = realloc(methods[i], sizeof(**methods)*nSelectors);
methods[i][nSelectors-1] = method_dnu;
}
}
return symbol->selector;
}
int findClass(char *class)
{
return ensureClass(intern(class));
}
int findSelector(char *selector)
{
return ensureSelector(intern(selector));
}
void addMethod(int class, int selector, method_t method)
{
methods[class][selector] = method;
}
#define lookup(C, S) (methods[C][S])
struct Object {
int class;
};
#define send(R, M, ...) ({ struct Object *__ = (struct Object *)(R); lookup(__->class, _selector_##M)(__, ##__VA_ARGS__); })
struct __oop { int class; };
typedef struct __oop *oop;
#include <math.h>
struct Point { int class; double x, y; };
oop newPoint(double x, double y)
{
struct Point *self = calloc(1, sizeof *self);
self->x = x;
self->y = y;
self->class = findClass("Point");
return (struct __oop *) self;
}
double Point_magnitude(struct __oop *__self)
{
struct Point *self = (struct Point *) __self;
printf("point method : %f\n", sqrt(self->x * self->x * self->y * self->y));
return sqrt(self->x * self->x * self->y * self->y);
}
double Point_getX(struct __oop *__self)
{
struct Point *self = (struct Point *) __self;
printf("point method : %f\n", self->x);
return self->x;
}
int main()
{
int _selector_getX= findSelector("getX");
int _selector_magnitude= findSelector("magnitude");
int _class_Point= findClass("Point");
addMethod(_class_Point, _selector_getX, (method_t) Point_getX);
addMethod(_class_Point, _selector_magnitude, (method_t) Point_magnitude);
oop p = newPoint(3, 4);
send(p, magnitude);
send(p, getX);
return 0;
}