class.h 1.5 KB

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  1. /*
  2. * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
  3. * See the copyright notice in the ACK home directory, in the file "Copyright".
  4. */
  5. /* $Id$ */
  6. /* U S E O F C H A R A C T E R C L A S S E S */
  7. /* As a starter, chars are divided into classes, according to which
  8. token they can be the start of.
  9. At present such a class number is supposed to fit in 4 bits.
  10. */
  11. #define class(ch) (tkclass[ch])
  12. /* Being the start of a token is, fortunately, a mutual exclusive
  13. property, so, although there are less than 16 classes they can be
  14. packed in 4 bits.
  15. */
  16. #define STSKIP 0 /* spaces and so on: skipped characters */
  17. #define STNL 1 /* newline character(s): update linenumber etc. */
  18. #define STGARB 2 /* garbage ascii character: not allowed in C */
  19. #define STSIMP 3 /* this character can occur as token in C */
  20. #define STCOMP 4 /* this one can start a compound token in C */
  21. #define STIDF 5 /* being the initial character of an identifier */
  22. #define STCHAR 6 /* the starter of a character constant */
  23. #define STSTR 7 /* the starter of a string */
  24. #define STNUM 8 /* the starter of a numeric constant */
  25. #define STEOI 9 /* End-Of-Information mark */
  26. /* But occurring inside a token is not, so we need 1 bit for each
  27. class. This is implemented as a collection of tables to speed up
  28. the decision whether a character has a special meaning.
  29. */
  30. #define in_idf(ch) (inidf[ch])
  31. #define is_oct(ch) (isoct[ch])
  32. #define is_dig(ch) (isdig[ch])
  33. #define is_hex(ch) (ishex[ch])
  34. extern char tkclass[];
  35. extern char inidf[], isoct[], isdig[], ishex[];