Programs/ctb_internal.h

/*
 * BRLTTY - A background process providing access to the console screen (when in
 *          text mode) for a blind person using a refreshable braille display.
 *
 * Copyright (C) 1995-2023 by The BRLTTY Developers.
 *
 * BRLTTY comes with ABSOLUTELY NO WARRANTY.
 *
 * This is free software, placed under the terms of the
 * GNU Lesser General Public License, as published by the Free Software
 * Foundation; either version 2.1 of the License, or (at your option) any
 * later version. Please see the file LICENSE-LGPL for details.
 *
 * Web Page: http://brltty.app/
 *
 * This software is maintained by Dave Mielke <dave@mielke.cc>.
 */

#ifndef BRLTTY_INCLUDED_CTB_INTERNAL
#define BRLTTY_INCLUDED_CTB_INTERNAL

#include <stdio.h>

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

#define BYTE unsigned char

#define HASHNUM 1087
#define CTH(x) (((x[0]<<8)+x[1])%HASHNUM)

typedef uint32_t ContractionTableOffset;

typedef enum {
  CTC_Space       = 0X01,
  CTC_Letter      = 0X02,
  CTC_Digit       = 0X04,
  CTC_Punctuation = 0X08,
  CTC_UpperCase   = 0X10,
  CTC_LowerCase   = 0X20
} ContractionTableCharacterAttribute;
typedef uint32_t ContractionTableCharacterAttributes;

typedef struct {
  wchar_t value;
  ContractionTableOffset rules;
  ContractionTableOffset always;
  ContractionTableCharacterAttributes attributes;
} ContractionTableCharacter;

typedef enum {
  CTO_CapitalSign, /*dot pattern for capital sign*/
  CTO_BeginCapitalSign, /*dot pattern for beginning capital block*/
  CTO_EndCapitalSign, /*dot pattern for ending capital block*/

  CTO_LetterSign, /*dot pattern for letter sign*/
  CTO_NumberSign, /*number sign*/

  CTO_Literal, /*don't translate this string*/
  CTO_Always, /*always use this contraction*/
  CTO_Repeatable, /*take just the first, i.e. multiple blanks*/

  CTO_LargeSign, /*and, for, of, the, with*/
  CTO_LastLargeSign, /*a*/
  CTO_WholeWord, /*whole word contraction*/
  CTO_JoinedWord, /*to, by, into*/
  CTO_LowWord, /*enough, were, was, etc.*/
  CTO_Contraction, /*multiletter word sign that needs letsign*/

  CTO_SuffixableWord, /*whole word or beginning of word*/
  CTO_PrefixableWord, /*whole word or end of word*/
  CTO_BegWord, /*beginning of word only*/
  CTO_BegMidWord, /*beginning or middle of word*/
  CTO_MidWord, /*middle of word only*/
  CTO_MidEndWord, /*middle or end of word*/
  CTO_EndWord, /*end of word only*/

  CTO_PrePunc, /*punctuation in string at beginning of word*/
  CTO_PostPunc, /*punctuation in string at end of word*/

  CTO_BegNum, /*beginning of number*/
  CTO_MidNum, /*middle of number, e.g., decimal point*/
  CTO_EndNum, /*end of number*/

  CTO_Class, /*define a character class*/
  CTO_After, /*only match if after character in class*/
  CTO_Before, /*only match if before character in class*/

  CTO_Replace, /*replace text*/

  CTO_None /*for internal use only*/
} ContractionTableOpcode;

extern const wchar_t *getContractionTableOpcodeName (ContractionTableOpcode opcode);

typedef struct {
  ContractionTableOffset next; /*next entry*/
  ContractionTableOpcode opcode; /*rule for testing validity of replacement*/
  ContractionTableCharacterAttributes after; /*character types which must foollow*/
  ContractionTableCharacterAttributes before; /*character types which must precede*/
  BYTE findlen; /*length of string to be replaced*/
  BYTE replen; /*length of replacement string*/
  wchar_t findrep[]; /*find and replacement strings*/
} ContractionTableRule;

typedef struct {
  ContractionTableOffset capitalSign; /*capitalization sign*/
  ContractionTableOffset beginCapitalSign; /*begin capitals sign*/
  ContractionTableOffset endCapitalSign; /*end capitals sign*/
  ContractionTableOffset letterSign; /*letter sign*/
  ContractionTableOffset numberSign; /*number sign*/
  ContractionTableOffset characters;
  uint32_t characterCount;
  ContractionTableOffset rules[HASHNUM]; /*locations of multi-character rules in table*/
} ContractionTableHeader;

typedef struct {
  const ContractionTableRule *always;
  ContractionTableCharacterAttributes attributes;

  wchar_t value;
  wchar_t uppercase;
  wchar_t lowercase;
} CharacterEntry;

typedef struct {
  void (*destroy) (ContractionTable *table);
} ContractionTableManagementMethods;

typedef struct ContractionTableTranslationMethodsStruct ContractionTableTranslationMethods;
typedef const ContractionTableTranslationMethods *GetContractionTableTranslationMethodsFunction (void);
extern GetContractionTableTranslationMethodsFunction getContractionTableTranslationMethods_native;
extern GetContractionTableTranslationMethodsFunction getContractionTableTranslationMethods_external;
extern GetContractionTableTranslationMethodsFunction getContractionTableTranslationMethods_louis;

typedef struct {
  union {
    ContractionTableHeader *fields;
    const unsigned char *bytes;
  } header;

  size_t size;
} InternalContractionTable;

struct ContractionTableStruct {
  const ContractionTableManagementMethods *managementMethods;
  const ContractionTableTranslationMethods *translationMethods;

  struct {
    CharacterEntry *array;
    unsigned int size;
    unsigned int count;
  } characters;

  struct {
    ContractionTableRule **array;
    unsigned int size;
    unsigned int count;
  } rules;

  union {
    InternalContractionTable internal;

    struct {
      char *command;
      FILE *standardInput;
      FILE *standardOutput;
      unsigned commandStarted:1;

      struct {
        char *buffer;
        size_t size;
      } input;
    } external;

#ifdef LOUIS_TABLES_DIRECTORY
    struct {
      char *tableList;
    } louis;
#endif /* LOUIS_TABLES_DIRECTORY */
  } data;
};

extern int startContractionCommand (ContractionTable *table);
extern void stopContractionCommand (ContractionTable *table);

extern const unsigned char *getInternalContractionTableBytes (void);

#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* BRLTTY_INCLUDED_CTB_INTERNAL */