Category : C Source Code
Archive   : CPAREN.ZIP
Filename : CPAREN.H

/*
* Copyright (c) 1984 by
* Tektronix, Incorporated Beaverton, Oregon 97077
* All rights reserved.
*
* Permission is hereby granted for personal, non-commercial
* reproduction and use of this program, provided that this
* notice is included in any copy.
*/

#ifdef RCSNAME
static char *RCSNAME = "$Header: cparen.h,v 1.12 84/04/05 09:21:51 bradn Stable $";
#else

#define TRUE 1
#define FALSE 0

#ifdef VARS
char *cmd; /* the name of this command (for error msgs) */
#else
extern char *cmd;
#endif

struct lexed { /* one unit of the lex'ed input list */
char *l_text; /* text associated with this token */
struct lexed *l_prev; /* previous token in the list */
struct lexed *l_next; /* next token in the list */
int l_val; /* this token's value (yylval'ish) */
};

extern struct lexed *nxttok(); /* used by lex to add a token to the list */
extern struct lexed *instok(); /* used by everybody to insert tokens */

struct node { /* a node of an expression subtree */
int n_op;
int n_flags;
#define HASL 1 /* 'has a left child' */
#define HASR 2 /* 'has a right child' */
#define BINARY (HASL | HASR)
#define HASPAR 4 /* 'has enclosing parens' */
#define hasl(np) ((np)->n_flags & HASL)
#define hasr(np) ((np)->n_flags & HASR)
#define haspar(np) ((np)->n_flags & HASPAR)
/*
* n_ledge and n_redge are the left and right
* edges of the sublist of tokens associated
* with this node.
* If haspar() is true, these pointers refer
* to the left and right paren tokens in the
* input token list.
*/
struct lexed *n_ledge;
struct lexed *n_redge;
};

extern struct node *bld(); /* used by yacc rules to return node info */

#ifndef PARSER /* yacc generates the definition of yylval */
extern YYSTYPE yylval;
#endif

#define NIL ((struct node *) 0)
#ifdef VARS
struct node nonode;
#else
extern struct node nonode;
#endif
#define NOP (&nonode) /* a no-op node pointer */

#ifdef VARS
struct lexed firsttok; /* the left edge of the token list */
#else
extern struct lexed firsttok;
#endif
#ifdef VARS
struct lexed lasttok; /* the right edge of the token list */
#else
extern struct lexed lasttok;
#endif

#endif