/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkParseString.h

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
/*-------------------------------------------------------------------------
  Copyright (c) 2012 David Gobbi.

  Contributed to the VisualizationToolkit by the author in April 2012
  under the terms of the Visualization Toolkit 2008 copyright.
-------------------------------------------------------------------------*/

/**
  This file provides string handling routines.

  The two important jobs done by these routines are string tokenization
  and string caching.

  Tokenization is done as per the rules of a C++ preprocessor, and
  breaks the strings into ids, literals, and operators.  Any string
  is a valid input for the tokenizer, and it is up to the parser to
  decide if the resulting tokens are valid within the grammar.  The
  two primary tokenization functions are vtkParse_InitTokenizer()
  and vtkParse_NextToken().

  Caching refers to how string memory management is done.  The
  parser uses "const char *" for all strings, and expects all strings
  to be persistent and constant.  These conditions are automatically
  met by static strings, but dynamically-generated strings must be
  cached until the parse is complete.  The primary caching functions
  are vtkParse_CacheString() and vtkParse_FreeStringCache().
*/

#ifndef vtkParseString_h
#define vtkParseString_h

#include "vtkWrappingToolsModule.h"
#include <stddef.h>

#ifdef __cplusplus
extern "C"
{
#endif

  /**
   * Various important char types for tokenization
   */
  typedef enum parse_char_type_
  {
    CPRE_NONDIGIT = 0x01, /* A-Z a-z and _ */
    CPRE_DIGIT = 0x02,    /* 0-9 */
    CPRE_XDIGIT = 0x03,   /* 0-9 A-Z a-z and _ */
    CPRE_EXTEND = 0x04,   /* non-ascii character */
    CPRE_ID = 0x05,       /* starting char for identifier */
    CPRE_XID = 0x07,      /* continuing char for identifier */
    CPRE_HEX = 0x08,      /* 0-9 A-F a-f hexadecimal digits */
    CPRE_SIGN = 0x10,     /* +- (sign for floats) */
    CPRE_QUOTE = 0x20,    /* " and ' */
    CPRE_HSPACE = 0x40,   /* space, tab, carriage return */
    CPRE_VSPACE = 0x80,   /* newline, vertical tab, form feed */
    CPRE_WHITE = 0xC0,    /* all whitespace characters */
  } parse_char_type;

  /**
   * check if a char is of a certain type
   */
  VTKWRAPPINGTOOLS_EXPORT int vtkParse_CharType(char c, int bits);

  /**
   * Whitespace types that can be used with the tokenizer.
   * - WS_DEFAULT treats newlines and formfeeds as regular whitespace.
   * - WS_PREPROC treats newline as end-of-line, not as whitespace.
   * - WS_COMMENT treats comments as tokens, not as whitespace.
   */
  typedef enum parse_space_t_
  {
    WS_DEFAULT = CPRE_WHITE,           /* skip all whitespace */
    WS_PREPROC = CPRE_HSPACE,          /* skip horizontal whitespace only */
    WS_COMMENT = (CPRE_WHITE | 0x100), /* comments as tokens */
  } parse_space_t;

  /**
   * Preprocessor tokens for C++.
   */
  typedef enum preproc_token_t_
  {
    TOK_OTHER = 257,
    TOK_ID,         /* any id */
    TOK_CHAR,       /* char literal */
    TOK_STRING,     /* string literal */
    TOK_NUMBER,     /* any numeric literal */
    TOK_COMMENT,    /* C or C++ comment */
    TOK_DBLHASH,    /* ## */
    TOK_SCOPE,      /* :: */
    TOK_INCR,       /* ++ */
    TOK_DECR,       /* -- */
    TOK_RSHIFT,     /* >> */
    TOK_LSHIFT,     /* << */
    TOK_AND,        /* && */
    TOK_OR,         /* || */
    TOK_EQ,         /* == */
    TOK_NE,         /* != */
    TOK_GE,         /* >= */
    TOK_LE,         /* <= */
    TOK_ADD_EQ,     /* += */
    TOK_SUB_EQ,     /* -= */
    TOK_MUL_EQ,     /* *= */
    TOK_DIV_EQ,     /* /= */
    TOK_MOD_EQ,     /* %= */
    TOK_AND_EQ,     /* &= */
    TOK_OR_EQ,      /* |= */
    TOK_XOR_EQ,     /* ^= */
    TOK_ARROW,      /* -> */
    TOK_DOT_STAR,   /* .* */
    TOK_ARROW_STAR, /* ->* */
    TOK_RSHIFT_EQ,  /* >>= */
    TOK_LSHIFT_EQ,  /* <<= */
    TOK_ELLIPSIS,   /* ... */
  } preproc_token_t;

  /**
   * A struct for going through a string one token at a time.
   * If ws is set to WS_PREPROC, then tokenization stops when a
   * newline or null is encountered.  If ws is set to WS_DEFAULT,
   * then tokenization only stops when a null is encountered.  If
   * ws is set to WS_COMMENT, then tokenization stops only when
   * a null is encountered, and comments are returned as tokens
   * instead of being skipped as whitespace.
   */
  typedef struct StringTokenizer_
  {
    int tok;           /* the current token */
    unsigned int hash; /* the hash of the current token, if it is an id */
    const char* text;  /* the text for the current token, not null-teminated */
    size_t len;        /* the length of the current token */
    parse_space_t ws;  /* controls what to consider as whitespace */
  } StringTokenizer;

  /**
   * Initialize the tokenizer and get the first token.
   */
  VTKWRAPPINGTOOLS_EXPORT
  void vtkParse_InitTokenizer(StringTokenizer* tokens, const char* text, parse_space_t wstype);

  /**
   * Return the next preprocessor token, or '0' if none left.
   */
  VTKWRAPPINGTOOLS_EXPORT
  int vtkParse_NextToken(StringTokenizer* tokens);

  /**
   * Skip over whitespace.
   * Return the number of chars until the first non-whitespace token.
   * Set spacetype to WS_DEFAULT, WS_PREPROC, or WS_COMMENT.
   */
  VTKWRAPPINGTOOLS_EXPORT
  size_t vtkParse_SkipWhitespace(const char* cp, parse_space_t spacetype);

  /**
   * Skip over a comment, C style or C++ style.
   * Return the number of chars until the end of the comment.
   */
  VTKWRAPPINGTOOLS_EXPORT
  size_t vtkParse_SkipComment(const char* cp);

  /**
   * Skip over a string in double or single quotes.
   * Return the number of chars until the end of the quotes.
   */
  VTKWRAPPINGTOOLS_EXPORT
  size_t vtkParse_SkipQuotes(const char* cp);

  /**
   * Skip over a number.  Uses preprocessor semantics.
   * Return the number of chars until the end of the number.
   */
  VTKWRAPPINGTOOLS_EXPORT
  size_t vtkParse_SkipNumber(const char* cp);

  /**
   * Skip over an identifier.
   * Return the number of chars until the end of the identifier.
   */
  VTKWRAPPINGTOOLS_EXPORT
  size_t vtkParse_SkipId(const char* cp);

  /**
   * Compute the hash for a id, for use in hash table lookups.
   * This stops at the first non-Id character, so it is safe to use
   * on a string that is not null-terminated as long as there is either
   * whitespace or an operator character before the end of the string.
   * It can be used on null-terminated strings as well, of course.
   */
  VTKWRAPPINGTOOLS_EXPORT
  unsigned int vtkParse_HashId(const char* cp);

  /**
   * Decode a single unicode character from utf8, or set error flag to 1.
   * The character pointer will be advanced by one if an error occurred,
   * and the return value will be the value of the first octet.
   */
  VTKWRAPPINGTOOLS_EXPORT
  unsigned int vtkParse_DecodeUtf8(const char** cpp, int* error_flag);

  /**
   * StringCache provides a simple way of allocating strings centrally.
   * It eliminates the need to allocate and free each individual string,
   * which makes the code simpler and more efficient.
   */
  typedef struct StringCache_
  {
    unsigned long NumberOfChunks;
    char** Chunks;
    size_t ChunkSize;
    size_t Position;
  } StringCache;

  /**
   * Initialize the string cache.
   */
  VTKWRAPPINGTOOLS_EXPORT
  void vtkParse_InitStringCache(StringCache* cache);

  /**
   * Allocate a new string from the cache.
   * A total of n+1 bytes will be allocated, to leave room for null.
   */
  VTKWRAPPINGTOOLS_EXPORT
  char* vtkParse_NewString(StringCache* cache, size_t n);

  /**
   * Cache a string so that it can then be used in the vtkParse data
   * structures.  The string will last until the application exits.
   * At most 'n' chars will be copied, and the string will be terminated.
   * If a null pointer is provided, then a null pointer will be returned.
   */
  VTKWRAPPINGTOOLS_EXPORT
  const char* vtkParse_CacheString(StringCache* cache, const char* cp, size_t n);

  /**
   * Free all strings that were created with vtkParse_NewString() or
   * with vtkParse_CacheString().
   */
  VTKWRAPPINGTOOLS_EXPORT
  void vtkParse_FreeStringCache(StringCache* cache);

  /**
   * Compute a hash for a string, using the first n bytes.
   */
  VTKWRAPPINGTOOLS_EXPORT
  unsigned int vtkParse_HashString(const char* cp, size_t n);

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif
/* VTK-HeaderTest-Exclude: vtkParseString.h */
