usr/src/bin/csh/char.h

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley Software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *      @(#)char.h      5.3 (Berkeley) %G%
 */

/*
 * Table for spotting special characters quickly
 *
 * Makes for very obscure but efficient coding.
 */

extern unsigned short _cmap[];

#define _Q      0x01            /* '" */
#define _Q1     0x02            /* ` */
#define _SP     0x04            /* space and tab */
#define _NL     0x08            /* \n */
#define _META   0x10            /* lex meta characters, sp #'`";&<>()|\t\n */
#define _GLOB   0x20            /* glob characters, *?{[` */
#define _ESC    0x40            /* \ */
#define _DOL    0x80            /* $ */
#define _DIG   0x100            /* 0-9 */
#define _LET   0x200            /* a-z, A-Z, _ */

#define cmap(c, bits)   (_cmap[(unsigned char)(c)] & (bits))

#define isglob(c)       cmap(c, _GLOB)
#define isspace(c)      cmap(c, _SP)
#define isspnl(c)       cmap(c, _SP|_NL)
#define ismeta(c)       cmap(c, _META)
#define digit(c)        cmap(c, _DIG)
#define letter(c)       cmap(c, _LET)
#define alnum(c)        (digit(c) || letter(c))