/* Copyright (c) 1986 Regents of the University of California */

/* SCCSid "@(#)calcomp.h 2.1 11/12/91 LBL" */

/*
 *  calcomp.h - header file for expression parser.
 *
 */
				/* EPNODE types */
#define  VAR            1
#define  NUM            2
#define  UMINUS         3
#define  CHAN           4
#define  FUNC           5
#define  ARG            6
#define  TICK           7
#define  SYM            8
				/* also: '+', '-', '*', '/', '^', '=', ':' */

typedef struct {
    char  *fname;               /* function name */
    short  nargs;               /* # of required arguments */
    short  atyp;                /* assignment type (':' or '=') */
    double  (*f)();             /* pointer to function */
}  LIBR;                /* a library function */

typedef struct epnode {
    int  type;                  /* node type */
    struct epnode  *sibling;    /* next child this level */
    union {
	struct epnode  *kid;    /* first child */
	double  num;            /* number */
	char  *name;            /* symbol name */
	int  chan;              /* channel number */
	long  tick;             /* timestamp */
	struct vardef {
	    char  *name;                /* variable name */
	    int  nlinks;                /* number of references */
	    struct epnode  *def;        /* definition */
	    LIBR  *lib;                 /* library definition */
	    struct vardef  *next;       /* next in hash list */
	}  *ln;                 /* link */
    } v;                /* value */
}  EPNODE;      /* an expression node */

typedef struct vardef  VARDEF;  /* a variable definition */

#define  MAXWORD        63              /* maximum word/id length */
#define  CNTXMARK       '`'             /* context mark */

#define  isid(c)        (isalnum(c) || (c) == '_' || \
			(c) == '.' || (c) == CNTXMARK)

extern double  eval(), varvalue(), chanvalue(), funvalue();
extern double  argument(), getnum();
extern double  (*eoper[])();
extern int  getinum();
extern char  *getname(), *qualname(), *setcontext(), *argfun();
extern EPNODE  *eparse(), *ekid(), *dlookup(), *dpop(), *dfirst(), *dnext();
extern EPNODE  *getdefn(), *getchan();
extern EPNODE  *getE1(), *getE2(), *getE3(), *getE4(), *getE5(), *rconst();
extern VARDEF  *varinsert(), *varlookup(), *argf();
extern LIBR  *liblookup();
extern long  eclock;
extern int  nextc;

#define  evalue(ep)     (*eoper[(ep)->type])(ep)