Data commit

Task/First-class-environments/C/first-class-environments.c

@@ -0,0 +1,36 @@
+#include <stdio.h>
+
+#define JOBS 12
+#define jobs(a) for (switch_to(a = 0); a < JOBS || !printf("\n"); switch_to(++a))
+typedef struct { int seq, cnt; } env_t;
+
+env_t env[JOBS] = {{0, 0}};
+int *seq, *cnt;
+
+void hail()
+{
+	printf("% 4d", *seq);
+	if (*seq == 1) return;
+	++*cnt;
+	*seq = (*seq & 1) ? 3 * *seq + 1 : *seq / 2;
+}
+
+void switch_to(int id)
+{
+	seq = &env[id].seq;
+	cnt = &env[id].cnt;
+}
+
+int main()
+{
+	int i;
+	jobs(i) { env[i].seq = i + 1; }
+
+again:	jobs(i) { hail(); }
+	jobs(i) { if (1 != *seq) goto again; }
+
+	printf("COUNTS:\n");
+	jobs(i) { printf("% 4d", *cnt); }
+
+	return 0;
+}