#ifndef _PLY_NODE_H
#define _PLY_NODE_H

#include <stdint.h>
#include <stdio.h>

#include "type.h"

typedef struct node node_t;

struct cons {
	node_t *car;
	node_t *cdr;
};

typedef enum op {
	OP_AGG = '@',
	OP_CALL = '(',
	OP_DEREF = '*',
	OP_DOT = '.',
	OP_MAP = '{',
} op_t;

typedef enum ntype {
	N_CONS,

	N_OP,
	N_IDENT,
	N_NUM,
	N_STRING,
} ntype_t;

struct node {
	ntype_t ntype;

	union {
		/* atom_t atom; */
		struct cons cons;

		op_t op;
		char *ident;
		int64_t num;
		char *string;
	};

	node_t *up;
	type_t *type;
};

/* debug */
typedef struct ndump_info {
	FILE *fp;
	int indent;
} ndump_info_t;

void ndump(node_t *n, ndump_info_t *info);


typedef int (*walk_fn)(node_t *, void *);
int nwalk(node_t *n, walk_fn pre, walk_fn post, void *ctx);

/* high-level constructors */
node_t *ncall(char *name, node_t *args);
node_t *nmap (char *name, node_t *key);


/* basic constructors */
node_t *ncons  (node_t *car, node_t *cdr);
node_t *nop    (op_t op);
node_t *nident (char *name);
node_t *nnum   (int64_t num);
node_t *nstring(char *string);


/* utilities */

static inline int nop_is(node_t *n, op_t op)
{
	if (!n || (n->ntype != N_OP))
		return 0;

	return n->op == op;
}

static inline node_t *ncar(node_t *n)
{
	if (!n || (n->ntype != N_CONS))
		return NULL;

	return n->cons.car;
}

static inline node_t *ncdr(node_t *n)
{
	if (!n || (n->ntype != N_CONS))
		return NULL;

	return n->cons.cdr;
}

static inline node_t *nup(node_t *n)
{

	return n? n->up : NULL;
}

#endif	/* _PLY_NODE_H */