#ifndef _MSPH_EXPR_H
#define _MSPH_EXPR_H

#include <sys/queue.h>

#include "msph/common.h"

/*
 *
 *
 * TOKENS
 * lbrace		{
 * rbrace		}
 * lbrak		[
 * rbrak		]
 * lparen		(
 * rparen		)
 * colon		:
 * equals		=
 *
 * op_and		&
 * op_or		|
 * op_impl		=>
 * op_sub		<:
 *
 * kw_type		type
 * kw_nominal		nominal
 * kw_member		member
 * kw_check		check
 * kw_box		box
 * kw_forall		forall
 *
 * k_true		True
 * k_false		False
 *
 * ident		C, anid, ...
 *
 */


enum msph_tok_type {
	TOK_INVAL = -1,		// special: invalid, use to mark invalid toks
	TOK_EOF = 0,		// special: end-of-file
	TOK_LBRACE,		// {
	TOK_RBRACE,		// }
	TOK_LBRAK,		// [
	TOK_RBRAK,		// ]
	TOK_LPAREN,		// (
	TOK_RPAREN,		// )
	TOK_COLON,		// :
	TOK_EQUALS,		// =
	TOK_COMMA,		// ,
	TOK_DOT,		// .

	TOK_AMP,		// &
	TOK_PIPE,		// |
	TOK_IMPL,		// =>
	TOK_RARROW,		// ->
	TOK_SUB,		// <:

	TOK_KW_TYPE,		// type
	TOK_KW_NOMINAL,		// nominal
	TOK_KW_MEMBER,		// member
	TOK_KW_ASSERT,		// assert
	TOK_KW_BOX,		// box
	TOK_KW_FORALL,		// forall

	TOK_CONST_TRUE,		// True
	TOK_CONST_FALSE,	// False

	TOK_IDENT,		// identifiers
	TOK_WSPACE,		// whitespace

	TOK_NOPE		// special indicator: end of info array,
				//		      start of parsing
};

#define MSPH_TAB_WIDTH		8

union msph_token_data {
	char	str[MSPH_IDENT_LEN];
};

struct msph_token {
	int			type;
	struct msph_text_pos	pos;
	union msph_token_data	data;

	SLIST_ENTRY(msph_token)	entries;
};

#define MSPH_FILE_NAME_LEN	1024
#define MSPH_FILE_BUF_LEN	2048
#define MSPH_TOKEN_SRC_FILE	1

struct msph_token_src_file {
	FILE		*f;

	/* circular buffer for reading */
	size_t		pos;
	size_t		end;
	char		buf[MSPH_FILE_BUF_LEN];
};

#define MSPH_TOKEN_SRC_STR	2
struct msph_token_src_str {
	const char	*s;
	size_t		len;
	size_t		pos;
};

union msph_token_src_data {
	struct msph_token_src_file	file;
	struct msph_token_src_str	str;
};

struct msph_token_src {
	int				type;
	struct msph_text_pos		pos;
	union msph_token_src_data	inner;
};

struct msph_token_stream {
	struct msph_ctx		*ctx;

	char			name[MSPH_NAME_LEN];
	struct msph_token_src	src;
};

void msph_ctx_init(struct msph_ctx *);

struct msph_token_stream	*msph_token_stream_file(struct msph_ctx *,
				    const char *, FILE *);
struct msph_token_stream	*msph_token_stream_frombuf(struct msph_ctx *,
				    const char *, const char *, size_t);

int	msph_token_stream_close(struct msph_token_stream*);

ssize_t	msph_token_stream_read(struct msph_token *, size_t,
	    struct msph_token_stream *);
int	msph_token_stream_eof(struct msph_token_stream *);
int	msph_token_stream_print(struct msph_token_stream *, FILE *);

ssize_t	msph_token_str(char *, size_t, struct msph_token *);

struct msph_token *	msph_token_copy(struct msph_ctx *, struct msph_token *);


#endif /* _MSPH_EXPR_H */