/* * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands. * See the copyright notice in the ACK home directory, in the file "Copyright". */ /* $Id$ */ /* U S E O F C H A R A C T E R C L A S S E S */ /* As a starter, chars are divided into classes, according to which token they can be the start of. At present such a class number is supposed to fit in 4 bits. */ #define class(ch) (tkclass[ch]) /* Being the start of a token is, fortunately, a mutual exclusive property, so, although there are less than 16 classes they can be packed in 4 bits. */ #define STSKIP 0 /* spaces and so on: skipped characters */ #define STNL 1 /* newline character(s): update linenumber etc. */ #define STGARB 2 /* garbage ascii character: not allowed in C */ #define STSIMP 3 /* this character can occur as token in C */ #define STCOMP 4 /* this one can start a compound token in C */ #define STIDF 5 /* being the initial character of an identifier */ #define STCHAR 6 /* the starter of a character constant */ #define STSTR 7 /* the starter of a string */ #define STNUM 8 /* the starter of a numeric constant */ #define STEOI 9 /* End-Of-Information mark */ /* But occurring inside a token is not, so we need 1 bit for each class. This is implemented as a collection of tables to speed up the decision whether a character has a special meaning. */ #define in_idf(ch) (inidf[ch]) #define is_oct(ch) (isoct[ch]) #define is_dig(ch) (isdig[ch]) #define is_hex(ch) (ishex[ch]) extern char tkclass[]; extern char inidf[], isoct[], isdig[], ishex[];