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+/*
+** 2006 July 10
+**
+** The author disclaims copyright to this source code.
+**
+*************************************************************************
+** Defines the interface to tokenizers used by fulltext-search. There
+** are three basic components:
+**
+** sqlite3_tokenizer_module is a singleton defining the tokenizer
+** interface functions. This is essentially the class structure for
+** tokenizers.
+**
+** sqlite3_tokenizer is used to define a particular tokenizer, perhaps
+** including customization information defined at creation time.
+**
+** sqlite3_tokenizer_cursor is generated by a tokenizer to generate
+** tokens from a particular input.
+*/
+#ifndef _TOKENIZER_H_
+#define _TOKENIZER_H_
+
+/* TODO(shess) Only used for SQLITE_OK and SQLITE_DONE at this time.
+** If tokenizers are to be allowed to call sqlite3_*() functions, then
+** we will need a way to register the API consistently.
+*/
+#include "sqlite3.h"
+
+/*
+** Structures used by the tokenizer interface.
+*/
+typedef struct sqlite3_tokenizer sqlite3_tokenizer;
+typedef struct sqlite3_tokenizer_cursor sqlite3_tokenizer_cursor;
+typedef struct sqlite3_tokenizer_module sqlite3_tokenizer_module;
+
+struct sqlite3_tokenizer_module {
+ int iVersion; /* currently 0 */
+
+ /*
+ ** Create and destroy a tokenizer. argc/argv are passed down from
+ ** the fulltext virtual table creation to allow customization.
+ */
+ int (*xCreate)(int argc, const char **argv,
+ sqlite3_tokenizer **ppTokenizer);
+ int (*xDestroy)(sqlite3_tokenizer *pTokenizer);
+
+ /*
+ ** Tokenize a particular input. Call xOpen() to prepare to
+ ** tokenize, xNext() repeatedly until it returns SQLITE_DONE, then
+ ** xClose() to free any internal state. The pInput passed to
+ ** xOpen() must exist until the cursor is closed. The ppToken
+ ** result from xNext() is only valid until the next call to xNext()
+ ** or until xClose() is called.
+ */
+ /* TODO(shess) current implementation requires pInput to be
+ ** nul-terminated. This should either be fixed, or pInput/nBytes
+ ** should be converted to zInput.
+ */
+ int (*xOpen)(sqlite3_tokenizer *pTokenizer,
+ const char *pInput, int nBytes,
+ sqlite3_tokenizer_cursor **ppCursor);
+ int (*xClose)(sqlite3_tokenizer_cursor *pCursor);
+ int (*xNext)(sqlite3_tokenizer_cursor *pCursor,
+ const char **ppToken, int *pnBytes,
+ int *piStartOffset, int *piEndOffset, int *piPosition);
+};
+
+struct sqlite3_tokenizer {
+ sqlite3_tokenizer_module *pModule; /* The module for this tokenizer */
+ /* Tokenizer implementations will typically add additional fields */
+};
+
+struct sqlite3_tokenizer_cursor {
+ sqlite3_tokenizer *pTokenizer; /* Tokenizer for this cursor. */
+ /* Tokenizer implementations will typically add additional fields */
+};
+
+/*
+** Get the module for a tokenizer which generates tokens based on a
+** set of non-token characters. The default is to break tokens at any
+** non-alnum character, though the set of delimiters can also be
+** specified by the first argv argument to xCreate().
+*/
+/* TODO(shess) This doesn't belong here. Need some sort of
+** registration process.
+*/
+void get_simple_tokenizer_module(sqlite3_tokenizer_module **ppModule);
+
+#endif /* _TOKENIZER_H_ */