#include "pair.h"
#include <stdint.h>
#include <errno.h>

/** @return Constructs `a` and `b` as a pair. */
struct pair pair(const char *const a, const char *const b) {
	struct pair p;
	p.a = a, p.b = b;
	return p;
}

/** Doesn't check anything.
 @return Whether it was able to parse unsigned `p` to `n`. */
int pair_to_natural(const char *s, const char *const e, uint32_t *const n) {
	uint32_t accum = 0;
	while(s < e) {
		unsigned next = accum * 10 + (unsigned)(*s - '0');
		if(accum >= next) return errno = ERANGE, 0;
		accum = next;
		s++;
	}
	*n = accum;
	return 1;
}