--- /dev/null
+/* Copyright (C) 2006, Index Data ApS
+ * See the file LICENSE for details.
+ * $Id: nfa.h,v 1.1 2006-05-03 09:04:33 heikki Exp $
+ */
+
+/**
+ * \file nfa.h
+ * \brief NFA for character set normalizing
+ *
+ * The NFA is a character mathcing device. It consists of states
+ * and transitions between them. Each transition has a condition, which
+ * is a range of values.
+ *
+ * When matching, we always start at the first state, and find the longest
+ * possible sequence of input characters that match the ranges in the
+ * conditions, and that leads into a terminal state.
+ *
+ */
+
+#ifndef NFA_H
+#define NFA_H
+
+#include <yaz/yconfig.h>
+
+YAZ_BEGIN_CDECL
+
+/** \brief Internal character type */
+typedef unsigned int yaz_nfa_char;
+
+
+/** \brief The NFA itself
+ * The internals are hidden in nfa.c */
+typedef struct yaz_nfa yaz_nfa;
+
+/** \brief A state of the NFA */
+typedef struct yaz_nfa_state yaz_nfa_state;
+
+/** \brief Transition from one state to another */
+typedef struct yaz_nfa_transition yaz_nfa_transition;
+
+
+/** \brief Initialize the NFA without any states in it
+ *
+ * \return a pointer to the newly created NFA
+ *
+ * */
+yaz_nfa *yaz_nfa_init();
+
+/** \brief Destroy the whole thing */
+void yaz_nfa_destroy(
+ yaz_nfa *n /** the nfa to destroy */
+ );
+
+/** \brief Add a normal state to the NFA.
+ *
+ * The first state added will become the starting point.
+ * Returns a pointer to it, which you can safely ignore, or use in building
+ * transitions.
+ */
+yaz_nfa_state *yaz_nfa_add_state(
+ yaz_nfa *n /** The NFA to add the state to */
+ );
+
+
+/** \brief Sets the result pointer to a state
+ *
+ * Call with null to clear the pointer.
+ *
+ * \retval 0 ok
+ * \retval 1 The state already has a result!
+ */
+int yaz_nfa_set_result(
+ /** The NFA itsef */
+ yaz_nfa *n,
+ /** The state to which the result is added */
+ yaz_nfa_state *s,
+ /** The result. The NFA does not care what it is, just stores it */
+ void *result
+ );
+
+/** \brief Gets the result pointer from a state
+ *
+ * \retval NULL if no result set
+ */
+void *yaz_nfa_get_result(
+ yaz_nfa *n /** The NFA itself */,
+ yaz_nfa_state *s /** The state whose result you want */);
+
+/** \brief Set the backref number to a state.
+ *
+ * Each state can be the beginning and/or ending of a backref
+ * sequence. This call sets those flags in the states. After matching,
+ * we can get hold of the backrefs that matched, and use them in our
+ * translations.
+ *
+ * \param n the nfa
+ * \param s the state to add to
+ * \param backref_number is the number of the back reference. 0 for clearing
+ * \param is_start is 1 for start of the backref, 0 for end
+ * \return
+ * 0 for OK
+ * 1 if the backref is already set
+ *
+ *
+ */
+
+int yaz_nfa_set_backref(yaz_nfa *n, yaz_nfa_state *s,
+ int backref_number,
+ int is_start );
+
+/** \brief Get the backref number of a state.
+ *
+ * \param n the nfa
+ * \param s the state to add to
+ * \param is_start is 1 for start of the backref, 0 for end
+ * \return the backref number associated with the state, or 0 if none.
+ */
+
+int yaz_nfa_get_backref(yaz_nfa *n, yaz_nfa_state *s,
+ int is_start );
+
+/** \brief Add a transition to the NFA.
+ *
+ * Add a transition between two existing states. The condition
+ * is (as always) a range of yaz_nfa_chars.
+ * \param n the nfa
+ * \param from_state which state the transition is from
+ * \param to_state where the transition goes to
+ * \param range_start is the beginning of the range of values
+ * \param range_end is the end of the range of values
+ **/
+void yaz_nfa_add_transition(yaz_nfa *n,
+ yaz_nfa_state *from_state,
+ yaz_nfa_state *to_state,
+ yaz_nfa_char range_start,
+ yaz_nfa_char range_end);
+
+/** \brief Add an empty (epsilon) transition.
+ *
+ * \param n the nfa
+ * \param from_state which state the transition is from
+ * \param to_state where the transition goes to
+ **/
+void yaz_nfa_add_empty_transition( yaz_nfa *n,
+ yaz_nfa_state *from_state,
+ yaz_nfa_state *to_state);
+
+/** \brief Add a translation from a range to the NFA.
+ *
+ * \param n the nfa
+ * \param st the state to add this to. If null, adds to the initial state
+ * \param range_start is the beginning of the range of values
+ * \param range_end is the end of the range of values
+ *
+ * Checks if we already have a transition like this. If so, does not add
+ * a new one, but returns the target state. Otherwise creates a new state,
+ * and a transition to it.
+ */
+yaz_nfa_state *yaz_nfa_add_range( yaz_nfa *n,
+ yaz_nfa_state *st,
+ yaz_nfa_char range_start,
+ yaz_nfa_char range_end );
+
+/** \brief Add a sequence of transitions and states.
+ *
+ * Starting from state s (or from the initial state, if s is
+ * null), finds as much of seq as possible and inserts the rest.
+ * \Return the final state
+ */
+yaz_nfa_state *yaz_nfa_add_sequence( yaz_nfa *n,
+ yaz_nfa_state *s,
+ yaz_nfa_char *seq );
+
+
+/** \brief Find the longest possible match.
+ *
+ * \param n the nfa itself
+ * \param inbuff buffer of input data. Will be incremented when match
+ * \param incharsleft max number of inchars to use from inbuff
+ * \param result the result pointer from the nfa (what ever that is)
+ *
+ * In case of errors, returns the best match so far,
+ * which the caller is free to ignore.
+ *
+ * \retval 0 success
+ * \retval 1 no match found
+ * \retval 2 overrun'of input buffer
+ * \retval 3 looping too far
+ *
+ */
+
+int yaz_nfa_match(yaz_nfa *n, yaz_nfa_char **inbuff, size_t incharsleft,
+ void **result );
+
+#define YAZ_NFA_SUCCESS 0
+#define YAZ_NFA_NOMATCH 1
+#define YAZ_NFA_OVERRUN 2
+#define YAZ_NFA_LOOP 3
+
+
+/** \brief Get the first state of the NFA.
+ *
+ * \param n the nfa
+ *
+ * Useful for iterating through all states, probably calling get_result
+ * for each, and doing something to the results (freeing memory?)
+ *
+ * \returns a pointer to the first state, or NULL if none.
+ */
+yaz_nfa_state *yaz_nfa_get_first(yaz_nfa *n);
+
+/** \brief Get the next state of the NFA.
+ *
+ * \param n the nfa
+ * \param s the state to add to
+ * \return the next state, or NULL if no more.
+ */
+yaz_nfa_state *yaz_nfa_get_next(yaz_nfa *n, yaz_nfa_state *s);
+
+/** \brief Dump the NFA into a file .
+ *
+ * \param F The file handle to dump into (null => stdout)
+ * \param n the nfa
+ * \param strfunc can be used for converting the resultinfo a string.
+ *
+ * strfunc is a function like
+ * char *f( void *result);
+ * it takes the result, and converts into a printable string (which
+ * must be allocated somewhere by the caller). If the results are
+ * already printable, passing a null pointer here prints them with a %s
+ *
+ */
+void yaz_nfa_dump(FILE *F, yaz_nfa *n, char *(*strfunc)(void *) );
+
+
+YAZ_END_CDECL
+
+#endif
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