spell.h

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/*-------------------------------------------------------------------------
 *
 * spell.h
 *
 * Declarations for ISpell dictionary
 *
 * Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
 *
 * src/include/tsearch/dicts/spell.h
 *
 *-------------------------------------------------------------------------
 */
 
#ifndef __SPELL_H__
#define __SPELL_H__
 
#include "regex/regex.h"
#include "tsearch/dicts/regis.h"
#include "tsearch/ts_public.h"
 
/*
 * SPNode and SPNodeData are used to represent prefix tree (Trie) to store
 * a words list.
 */
struct SPNode;
 
typedef struct
{
    uint32      val:8,
                isword:1,
    /* Stores compound flags listed below */
                compoundflag:4,
    /* Reference to an entry of the AffixData field */
                affix:19;
    struct SPNode *node;
} SPNodeData;
 
/*
 * Names of FF_ are correlated with Hunspell options in affix file
 * https://hunspell.github.io/
 */
#define FF_COMPOUNDONLY     0x01
#define FF_COMPOUNDBEGIN    0x02
#define FF_COMPOUNDMIDDLE   0x04
#define FF_COMPOUNDLAST     0x08
#define FF_COMPOUNDFLAG     ( FF_COMPOUNDBEGIN | FF_COMPOUNDMIDDLE | \
                            FF_COMPOUNDLAST )
#define FF_COMPOUNDFLAGMASK     0x0f
 
typedef struct SPNode
{
    uint32      length;
    SPNodeData  data[FLEXIBLE_ARRAY_MEMBER];
} SPNode;
 
#define SPNHDRSZ    (offsetof(SPNode,data))
 
/*
 * Represents an entry in a words list.
 */
typedef struct spell_struct
{
    union
    {
        /*
         * flag is filled in by NIImportDictionary(). After
         * NISortDictionary(), d is used instead of flag.
         */
        char       *flag;
        /* d is used in mkSPNode() */
        struct
        {
            /* Reference to an entry of the AffixData field */
            int         affix;
            /* Length of the word */
            int         len;
        }           d;
    }           p;
    char        word[FLEXIBLE_ARRAY_MEMBER];
} SPELL;
 
#define SPELLHDRSZ  (offsetof(SPELL, word))
 
/*
 * If an affix uses a regex, we have to store that separately in a struct
 * that won't move around when arrays of affixes are enlarged or sorted.
 * This is so that it can be found to be cleaned up at context destruction.
 */
typedef struct aff_regex_struct
{
    regex_t     regex;
    MemoryContextCallback mcallback;
} aff_regex_struct;
 
/*
 * Represents an entry in an affix list.
 */
typedef struct aff_struct
{
    char       *flag;
    /* FF_SUFFIX or FF_PREFIX */
    uint32      type:1,
                flagflags:7,
                issimple:1,
                isregis:1,
                replen:14;
    char       *find;
    char       *repl;
    union
    {
        aff_regex_struct *pregex;
        Regis       regis;
    }           reg;
} AFFIX;
 
/*
 * affixes use dictionary flags too
 */
#define FF_COMPOUNDPERMITFLAG   0x10
#define FF_COMPOUNDFORBIDFLAG   0x20
#define FF_CROSSPRODUCT         0x40
 
/*
 * Don't change the order of these. Initialization sorts by these,
 * and expects prefixes to come first after sorting.
 */
#define FF_SUFFIX               1
#define FF_PREFIX               0
 
/*
 * AffixNode and AffixNodeData are used to represent prefix tree (Trie) to store
 * an affix list.
 */
struct AffixNode;
 
typedef struct
{
    uint32      val:8,
                naff:24;
    AFFIX     **aff;
    struct AffixNode *node;
} AffixNodeData;
 
typedef struct AffixNode
{
    uint32      isvoid:1,
                length:31;
    AffixNodeData data[FLEXIBLE_ARRAY_MEMBER];
} AffixNode;
 
#define ANHRDSZ        (offsetof(AffixNode, data))
 
typedef struct
{
    char       *affix;
    int         len;
    bool        issuffix;
} CMPDAffix;
 
/*
 * Type of encoding affix flags in Hunspell dictionaries
 */
typedef enum
{
    FM_CHAR,                    /* one character (like ispell) */
    FM_LONG,                    /* two characters */
    FM_NUM                      /* number, >= 0 and < 65536 */
} FlagMode;
 
/*
 * Structure to store Hunspell options. Flag representation depends on flag
 * type. These flags are about support of compound words.
 */
typedef struct CompoundAffixFlag
{
    union
    {
        /* Flag name if flagMode is FM_CHAR or FM_LONG */
        char       *s;
        /* Flag name if flagMode is FM_NUM */
        uint32      i;
    }           flag;
    /* we don't have a bsearch_arg version, so, copy FlagMode */
    FlagMode    flagMode;
    uint32      value;
} CompoundAffixFlag;
 
#define FLAGNUM_MAXSIZE     (1 << 16)
 
typedef struct
{
    int         maffixes;
    int         naffixes;
    AFFIX      *Affix;
 
    AffixNode  *Suffix;
    AffixNode  *Prefix;
 
    SPNode     *Dictionary;
    /* Array of sets of affixes */
    char      **AffixData;
    int         lenAffixData;
    int         nAffixData;
    bool        useFlagAliases;
 
    CMPDAffix  *CompoundAffix;
 
    bool        usecompound;
    FlagMode    flagMode;
 
    /*
     * All follow fields are actually needed only for initialization
     */
 
    /* Array of Hunspell options in affix file */
    CompoundAffixFlag *CompoundAffixFlags;
    /* number of entries in CompoundAffixFlags array */
    int         nCompoundAffixFlag;
    /* allocated length of CompoundAffixFlags array */
    int         mCompoundAffixFlag;
 
    /*
     * Remaining fields are only used during dictionary construction; they are
     * set up by NIStartBuild and cleared by NIFinishBuild.
     */
    MemoryContext buildCxt;     /* temp context for construction */
 
    /* Temporary array of all words in the dict file */
    SPELL     **Spell;
    int         nspell;         /* number of valid entries in Spell array */
    int         mspell;         /* allocated length of Spell array */
 
    /* These are used to allocate "compact" data without palloc overhead */
    char       *firstfree;      /* first free address (always maxaligned) */
    size_t      avail;          /* free space remaining at firstfree */
} IspellDict;
 
extern TSLexeme *NINormalizeWord(IspellDict *Conf, char *word);
 
extern void NIStartBuild(IspellDict *Conf);
extern void NIImportAffixes(IspellDict *Conf, const char *filename);
extern void NIImportDictionary(IspellDict *Conf, const char *filename);
extern void NISortDictionary(IspellDict *Conf);
extern void NISortAffixes(IspellDict *Conf);
extern void NIFinishBuild(IspellDict *Conf);
 
#endif