#ifndef _PLY_NODE_H
#define _PLY_NODE_H

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

#include "type.h"

typedef struct atom atom_t;
typedef struct expr expr_t;
typedef struct node node_t;

typedef enum atype {
	A_INVALID,
	A_IDENT,
	A_NUM,
	A_STRING,
} atype_t;

struct atom {
	atype_t atype;

	union {
		char *ident;
		int64_t num;
		char *string;
	};
};

typedef enum etype {
	E_INVALID = '\0',

	E_AGG = '@',
	E_CALL = '(',
	E_DEREF = '*',
	E_DOT = '.',
	E_MAP = 'm',
	E_SCOPE = '{',
	
} etype_t;

struct expr {
	etype_t etype;
	node_t *arg;
};

typedef enum ntype {
	N_INVALID,
	N_ATOM,
	N_EXPR,
} ntype_t;

struct node {
	ntype_t ntype;
	node_t *up;
	node_t *next;

	type_t *type;

	union {
		atom_t atom;
		expr_t expr;
	};
};

/* walk a node tree */

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


/* node constructors */

node_t *node_ident (char *name);
node_t *node_num   (int64_t num);
node_t *node_string(char *string);
node_t *node_expr  (etype_t etype, node_t *arg);
node_t *node_cons  (node_t *head, node_t *tail);


/* debug */

typedef struct node_dump_info {
	FILE *fp;
	int indent;
} node_dump_info_t;

void node_dump(node_t *n, node_dump_info_t *info);

#endif	/* _PLY_NODE_H */