
#include <stdlib.h>				/* for calloc, free */
#include "header.h"

extern struct SN_env *
SN_create_env(int S_size, int I_size, int B_size)
{
	struct SN_env *z = (struct SN_env *) calloc(1, sizeof(struct SN_env));

	if (z == NULL)
		return NULL;
	z->p = create_s();
	if (z->p == NULL)
		goto error;
	if (S_size)
	{
		int			i;

		z->S = (symbol * *) calloc(S_size, sizeof(symbol *));
		if (z->S == NULL)
			goto error;

		for (i = 0; i < S_size; i++)
		{
			z->S[i] = create_s();
			if (z->S[i] == NULL)
				goto error;
		}
		z->S_size = S_size;
	}

	if (I_size)
	{
		z->I = (int *) calloc(I_size, sizeof(int));
		if (z->I == NULL)
			goto error;
		z->I_size = I_size;
	}

	if (B_size)
	{
		z->B = (symbol *) calloc(B_size, sizeof(symbol));
		if (z->B == NULL)
			goto error;
		z->B_size = B_size;
	}

	return z;
error:
	SN_close_env(z);
	return NULL;
}

extern void
SN_close_env(struct SN_env * z)
{
	if (z == NULL)
		return;
	if (z->S_size)
	{
		int			i;

		for (i = 0; i < z->S_size; i++)
		{
			lose_s(z->S[i]);
		}
		free(z->S);
	}
	if (z->I_size)
		free(z->I);
	if (z->B_size)
		free(z->B);
	if (z->p)
		lose_s(z->p);
	free(z);
}

extern int
SN_set_current(struct SN_env * z, int size, const symbol * s)
{
	int			err = replace_s(z, 0, z->l, size, s, NULL);

	z->c = 0;
	return err;
}
