Check in the pristine copy of ICU 4.6...

icu46/source/i18n/cpdtrans.cpp

+/*
+**********************************************************************
+*   Copyright (C) 1999-2008, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+**********************************************************************
+*   Date        Name        Description
+*   11/17/99    aliu        Creation.
+**********************************************************************
+*/
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_TRANSLITERATION
+
+#include "unicode/unifilt.h"
+#include "unicode/uniset.h"
+#include "cpdtrans.h"
+#include "uvector.h"
+#include "tridpars.h"
+#include "cmemory.h"
+
+// keep in sync with Transliterator
+//static const UChar ID_SEP   = 0x002D; /*-*/
+static const UChar ID_DELIM = 0x003B; /*;*/
+static const UChar NEWLINE  = 10;
+
+// Empty string
+static const UChar EMPTY[] = {0}; //""
+static const UChar COLON_COLON[] = {0x3A, 0x3A, 0}; //"::"
+
+U_NAMESPACE_BEGIN
+
+const UChar CompoundTransliterator::PASS_STRING[] = { 0x0025, 0x0050, 0x0061, 0x0073, 0x0073, 0 }; // "%Pass"
+
+UOBJECT_DEFINE_RTTI_IMPLEMENTATION(CompoundTransliterator)
+
+/**
+ * Constructs a new compound transliterator given an array of
+ * transliterators.  The array of transliterators may be of any
+ * length, including zero or one, however, useful compound
+ * transliterators have at least two components.
+ * @param transliterators array of <code>Transliterator</code>
+ * objects
+ * @param transliteratorCount The number of
+ * <code>Transliterator</code> objects in transliterators.
+ * @param filter the filter.  Any character for which
+ * <tt>filter.contains()</tt> returns <tt>false</tt> will not be
+ * altered by this transliterator.  If <tt>filter</tt> is
+ * <tt>null</tt> then no filtering is applied.
+ */
+CompoundTransliterator::CompoundTransliterator(
+                           Transliterator* const transliterators[],
+                           int32_t transliteratorCount,
+                           UnicodeFilter* adoptedFilter) :
+    Transliterator(joinIDs(transliterators, transliteratorCount), adoptedFilter),
+    trans(0), count(0), numAnonymousRBTs(0)  {
+    setTransliterators(transliterators, transliteratorCount);
+}
+
+/**
+ * Splits an ID of the form "ID;ID;..." into a compound using each
+ * of the IDs. 
+ * @param id of above form
+ * @param forward if false, does the list in reverse order, and
+ * takes the inverse of each ID.
+ */
+CompoundTransliterator::CompoundTransliterator(const UnicodeString& id,
+                              UTransDirection direction,
+                              UnicodeFilter* adoptedFilter,
+                              UParseError& /*parseError*/,
+                              UErrorCode& status) :
+    Transliterator(id, adoptedFilter),
+    trans(0), numAnonymousRBTs(0) {
+    // TODO add code for parseError...currently unused, but
+    // later may be used by parsing code...
+    init(id, direction, TRUE, status);
+}
+
+CompoundTransliterator::CompoundTransliterator(const UnicodeString& id,
+                              UParseError& /*parseError*/,
+                              UErrorCode& status) :
+    Transliterator(id, 0), // set filter to 0 here!
+    trans(0), numAnonymousRBTs(0) {
+    // TODO add code for parseError...currently unused, but
+    // later may be used by parsing code...
+    init(id, UTRANS_FORWARD, TRUE, status);
+}
+
+
+/**
+ * Private constructor for use of TransliteratorAlias
+ */
+CompoundTransliterator::CompoundTransliterator(const UnicodeString& newID,
+                                              UVector& list,
+                                              UnicodeFilter* adoptedFilter,
+                                              int32_t anonymousRBTs,
+                                              UParseError& /*parseError*/,
+                                              UErrorCode& status) :
+    Transliterator(newID, adoptedFilter),
+    trans(0), numAnonymousRBTs(anonymousRBTs)
+{
+    init(list, UTRANS_FORWARD, FALSE, status);
+}
+
+/**
+ * Private constructor for Transliterator from a vector of
+ * transliterators.  The caller is responsible for fixing up the
+ * ID.
+ */
+CompoundTransliterator::CompoundTransliterator(UVector& list,
+                                               UParseError& /*parseError*/,
+                                               UErrorCode& status) :
+    Transliterator(EMPTY, NULL),
+    trans(0), numAnonymousRBTs(0)
+{
+    // TODO add code for parseError...currently unused, but
+    // later may be used by parsing code...
+    init(list, UTRANS_FORWARD, FALSE, status);
+    // assume caller will fixup ID
+}
+
+CompoundTransliterator::CompoundTransliterator(UVector& list,
+                                               int32_t anonymousRBTs,
+                                               UParseError& /*parseError*/,
+                                               UErrorCode& status) :
+    Transliterator(EMPTY, NULL),
+    trans(0), numAnonymousRBTs(anonymousRBTs)
+{
+    init(list, UTRANS_FORWARD, FALSE, status);
+}
+
+/**
+ * Finish constructing a transliterator: only to be called by
+ * constructors.  Before calling init(), set trans and filter to NULL.
+ * @param id the id containing ';'-separated entries
+ * @param direction either FORWARD or REVERSE
+ * @param idSplitPoint the index into id at which the
+ * adoptedSplitTransliterator should be inserted, if there is one, or
+ * -1 if there is none.
+ * @param adoptedSplitTransliterator a transliterator to be inserted
+ * before the entry at offset idSplitPoint in the id string.  May be
+ * NULL to insert no entry.
+ * @param fixReverseID if TRUE, then reconstruct the ID of reverse
+ * entries by calling getID() of component entries.  Some constructors
+ * do not require this because they apply a facade ID anyway.
+ * @param status the error code indicating success or failure
+ */
+void CompoundTransliterator::init(const UnicodeString& id,
+                                  UTransDirection direction,
+                                  UBool fixReverseID,
+                                  UErrorCode& status) {
+    // assert(trans == 0);
+
+    if (U_FAILURE(status)) {
+        return;
+    }
+
+    UVector list(status);
+    UnicodeSet* compoundFilter = NULL;
+    UnicodeString regenID;
+    if (!TransliteratorIDParser::parseCompoundID(id, direction,
+                                      regenID, list, compoundFilter)) {
+        status = U_INVALID_ID;
+        delete compoundFilter;
+        return;
+    }
+
+    TransliteratorIDParser::instantiateList(list, status);
+
+    init(list, direction, fixReverseID, status);
+
+    if (compoundFilter != NULL) {
+        adoptFilter(compoundFilter);
+    }
+}
+
+/**
+ * Finish constructing a transliterator: only to be called by
+ * constructors.  Before calling init(), set trans and filter to NULL.
+ * @param list a vector of transliterator objects to be adopted.  It
+ * should NOT be empty.  The list should be in declared order.  That
+ * is, it should be in the FORWARD order; if direction is REVERSE then
+ * the list order will be reversed.
+ * @param direction either FORWARD or REVERSE
+ * @param fixReverseID if TRUE, then reconstruct the ID of reverse
+ * entries by calling getID() of component entries.  Some constructors
+ * do not require this because they apply a facade ID anyway.
+ * @param status the error code indicating success or failure
+ */
+void CompoundTransliterator::init(UVector& list,
+                                  UTransDirection direction,
+                                  UBool fixReverseID,
+                                  UErrorCode& status) {
+    // assert(trans == 0);
+
+    // Allocate array
+    if (U_SUCCESS(status)) {
+        count = list.size();
+        trans = (Transliterator **)uprv_malloc(count * sizeof(Transliterator *));
+        /* test for NULL */
+        if (trans == 0) {
+            status = U_MEMORY_ALLOCATION_ERROR;
+            return;
+        }
+    }
+
+    if (U_FAILURE(status) || trans == 0) {
+         // assert(trans == 0);
+        return;
+    }
+
+    // Move the transliterators from the vector into an array.
+    // Reverse the order if necessary.
+    int32_t i;
+    for (i=0; i<count; ++i) {
+        int32_t j = (direction == UTRANS_FORWARD) ? i : count - 1 - i;
+        trans[i] = (Transliterator*) list.elementAt(j);
+    }
+
+    // If the direction is UTRANS_REVERSE then we may need to fix the
+    // ID.
+    if (direction == UTRANS_REVERSE && fixReverseID) {
+        UnicodeString newID;
+        for (i=0; i<count; ++i) {
+            if (i > 0) {
+                newID.append(ID_DELIM);
+            }
+            newID.append(trans[i]->getID());
+        }
+        setID(newID);
+    }
+
+    computeMaximumContextLength();
+}
+
+/**
+ * Return the IDs of the given list of transliterators, concatenated
+ * with ID_DELIM delimiting them.  Equivalent to the perlish expression
+ * join(ID_DELIM, map($_.getID(), transliterators).
+ */
+UnicodeString CompoundTransliterator::joinIDs(Transliterator* const transliterators[],
+                                              int32_t transCount) {
+    UnicodeString id;
+    for (int32_t i=0; i<transCount; ++i) {
+        if (i > 0) {
+            id.append(ID_DELIM);
+        }
+        id.append(transliterators[i]->getID());
+    }
+    return id; // Return temporary
+}
+
+/**
+ * Copy constructor.
+ */
+CompoundTransliterator::CompoundTransliterator(const CompoundTransliterator& t) :
+    Transliterator(t), trans(0), count(0), numAnonymousRBTs(-1) {
+    *this = t;
+}
+
+/**
+ * Destructor
+ */
+CompoundTransliterator::~CompoundTransliterator() {
+    freeTransliterators();
+}
+
+void CompoundTransliterator::freeTransliterators(void) {
+    if (trans != 0) {
+        for (int32_t i=0; i<count; ++i) {
+            delete trans[i];
+        }
+        uprv_free(trans);
+    }
+    trans = 0;
+    count = 0;
+}
+
+/**
+ * Assignment operator.
+ */
+CompoundTransliterator& CompoundTransliterator::operator=(
+                                             const CompoundTransliterator& t)
+{
+    Transliterator::operator=(t);
+    int32_t i = 0;
+    UBool failed = FALSE;
+    if (trans != NULL) {
+        for (i=0; i<count; ++i) {
+            delete trans[i];
+            trans[i] = 0;
+        }
+    }
+    if (t.count > count) {
+        if (trans != NULL) {
+            uprv_free(trans);
+        }
+        trans = (Transliterator **)uprv_malloc(t.count * sizeof(Transliterator *));
+    }
+    count = t.count;
+    if (trans != NULL) {
+        for (i=0; i<count; ++i) {
+            trans[i] = t.trans[i]->clone();
+            if (trans[i] == NULL) {
+                failed = TRUE;
+                break;
+            }
+        }
+    }
+
+    // if memory allocation failed delete backwards trans array
+    if (failed && i > 0) {
+        int32_t n;
+        for (n = i-1; n >= 0; n--) {
+            uprv_free(trans[n]);
+            trans[n] = NULL;
+        }
+    }
+    numAnonymousRBTs = t.numAnonymousRBTs;
+    return *this;
+}
+
+/**
+ * Transliterator API.
+ */
+Transliterator* CompoundTransliterator::clone(void) const {
+    return new CompoundTransliterator(*this);
+}
+
+/**
+ * Returns the number of transliterators in this chain.
+ * @return number of transliterators in this chain.
+ */
+int32_t CompoundTransliterator::getCount(void) const {
+    return count;
+}
+
+/**
+ * Returns the transliterator at the given index in this chain.
+ * @param index index into chain, from 0 to <code>getCount() - 1</code>
+ * @return transliterator at the given index
+ */
+const Transliterator& CompoundTransliterator::getTransliterator(int32_t index) const {
+    return *trans[index];
+}
+
+void CompoundTransliterator::setTransliterators(Transliterator* const transliterators[],
+                                                int32_t transCount) {
+    Transliterator** a = (Transliterator **)uprv_malloc(transCount * sizeof(Transliterator *));
+    if (a == NULL) {
+        return;
+    }
+    int32_t i = 0;
+    UBool failed = FALSE;
+    for (i=0; i<transCount; ++i) {
+        a[i] = transliterators[i]->clone();
+        if (a[i] == NULL) {
+            failed = TRUE;
+            break;
+        }
+    }
+    if (failed && i > 0) {
+        int32_t n;
+        for (n = i-1; n >= 0; n--) {
+            uprv_free(a[n]);
+            a[n] = NULL;
+        }
+        return;
+    }
+    adoptTransliterators(a, transCount);
+}
+
+void CompoundTransliterator::adoptTransliterators(Transliterator* adoptedTransliterators[],
+                                                  int32_t transCount) {
+    // First free trans[] and set count to zero.  Once this is done,
+    // orphan the filter.  Set up the new trans[].
+    freeTransliterators();
+    trans = adoptedTransliterators;
+    count = transCount;
+    computeMaximumContextLength();
+    setID(joinIDs(trans, count));
+}
+
+/**
+ * Append c to buf, unless buf is empty or buf already ends in c.
+ */
+static void _smartAppend(UnicodeString& buf, UChar c) {
+    if (buf.length() != 0 &&
+        buf.charAt(buf.length() - 1) != c) {
+        buf.append(c);
+    }
+}
+
+UnicodeString& CompoundTransliterator::toRules(UnicodeString& rulesSource,
+                                               UBool escapeUnprintable) const {
+    // We do NOT call toRules() on our component transliterators, in
+    // general.  If we have several rule-based transliterators, this
+    // yields a concatenation of the rules -- not what we want.  We do
+    // handle compound RBT transliterators specially -- those for which
+    // compoundRBTIndex >= 0.  For the transliterator at compoundRBTIndex,
+    // we do call toRules() recursively.
+    rulesSource.truncate(0);
+    if (numAnonymousRBTs >= 1 && getFilter() != NULL) {
+        // If we are a compound RBT and if we have a global
+        // filter, then emit it at the top.
+        UnicodeString pat;
+        rulesSource.append(COLON_COLON).append(getFilter()->toPattern(pat, escapeUnprintable)).append(ID_DELIM);
+    }
+    for (int32_t i=0; i<count; ++i) {
+        UnicodeString rule;
+
+        // Anonymous RuleBasedTransliterators (inline rules and
+        // ::BEGIN/::END blocks) are given IDs that begin with
+        // "%Pass": use toRules() to write all the rules to the output
+        // (and insert "::Null;" if we have two in a row)
+        if (trans[i]->getID().startsWith(PASS_STRING)) {
+            trans[i]->toRules(rule, escapeUnprintable);
+            if (numAnonymousRBTs > 1 && i > 0 && trans[i - 1]->getID().startsWith(PASS_STRING))
+                rule = UNICODE_STRING_SIMPLE("::Null;") + rule;
+
+        // we also use toRules() on CompoundTransliterators (which we
+        // check for by looking for a semicolon in the ID)-- this gets
+        // the list of their child transliterators output in the right
+        // format
+        } else if (trans[i]->getID().indexOf(ID_DELIM) >= 0) {
+            trans[i]->toRules(rule, escapeUnprintable);
+
+        // for everything else, use Transliterator::toRules()
+        } else {
+            trans[i]->Transliterator::toRules(rule, escapeUnprintable);
+        }
+        _smartAppend(rulesSource, NEWLINE);
+        rulesSource.append(rule);
+        _smartAppend(rulesSource, ID_DELIM);
+    }
+    return rulesSource;
+}
+
+/**
+ * Implement Transliterator framework
+ */
+void CompoundTransliterator::handleGetSourceSet(UnicodeSet& result) const {
+    UnicodeSet set;
+    result.clear();
+    for (int32_t i=0; i<count; ++i) {
+    result.addAll(trans[i]->getSourceSet(set));
+    // Take the example of Hiragana-Latin.  This is really
+    // Hiragana-Katakana; Katakana-Latin.  The source set of
+    // these two is roughly [:Hiragana:] and [:Katakana:].
+    // But the source set for the entire transliterator is
+    // actually [:Hiragana:] ONLY -- that is, the first
+    // non-empty source set.
+
+    // This is a heuristic, and not 100% reliable.
+    if (!result.isEmpty()) {
+        break;
+    }
+    }
+}
+
+/**
+ * Override Transliterator framework
+ */
+UnicodeSet& CompoundTransliterator::getTargetSet(UnicodeSet& result) const {
+    UnicodeSet set;
+    result.clear();
+    for (int32_t i=0; i<count; ++i) {
+    // This is a heuristic, and not 100% reliable.
+    result.addAll(trans[i]->getTargetSet(set));
+    }
+    return result;
+}
+
+/**
+ * Implements {@link Transliterator#handleTransliterate}.
+ */
+void CompoundTransliterator::handleTransliterate(Replaceable& text, UTransPosition& index,
+                                                 UBool incremental) const {
+    /* Call each transliterator with the same contextStart and
+     * start, but with the limit as modified
+     * by preceding transliterators.  The start index must be
+     * reset for each transliterator to give each a chance to
+     * transliterate the text.  The initial contextStart index is known
+     * to still point to the same place after each transliterator
+     * is called because each transliterator will not change the
+     * text between contextStart and the initial start index.
+     *
+     * IMPORTANT: After the first transliterator, each subsequent
+     * transliterator only gets to transliterate text committed by
+     * preceding transliterators; that is, the start (output
+     * value) of transliterator i becomes the limit (input value)
+     * of transliterator i+1.  Finally, the overall limit is fixed
+     * up before we return.
+     *
+     * Assumptions we make here:
+     * (1) contextStart <= start <= limit <= contextLimit <= text.length()
+     * (2) start <= start' <= limit'  ;cursor doesn't move back
+     * (3) start <= limit'            ;text before cursor unchanged
+     * - start' is the value of start after calling handleKT
+     * - limit' is the value of limit after calling handleKT
+     */
+    
+    /**
+     * Example: 3 transliterators.  This example illustrates the
+     * mechanics we need to implement.  C, S, and L are the contextStart,
+     * start, and limit.  gl is the globalLimit.  contextLimit is
+     * equal to limit throughout.
+     *
+     * 1. h-u, changes hex to Unicode
+     *
+     *    4  7  a  d  0      4  7  a
+     *    abc/u0061/u    =>  abca/u    
+     *    C  S       L       C   S L   gl=f->a
+     *
+     * 2. upup, changes "x" to "XX"
+     *
+     *    4  7  a       4  7  a
+     *    abca/u    =>  abcAA/u    
+     *    C  SL         C    S   
+     *                       L    gl=a->b
+     * 3. u-h, changes Unicode to hex
+     *
+     *    4  7  a        4  7  a  d  0  3
+     *    abcAA/u    =>  abc/u0041/u0041/u    
+     *    C  S L         C              S
+     *                                  L   gl=b->15
+     * 4. return
+     *
+     *    4  7  a  d  0  3
+     *    abc/u0041/u0041/u    
+     *    C S L
+     */
+
+    if (count < 1) {
+        index.start = index.limit;
+        return; // Short circuit for empty compound transliterators
+    }
+
+    // compoundLimit is the limit value for the entire compound
+    // operation.  We overwrite index.limit with the previous
+    // index.start.  After each transliteration, we update
+    // compoundLimit for insertions or deletions that have happened.
+    int32_t compoundLimit = index.limit;
+
+    // compoundStart is the start for the entire compound
+    // operation.
+    int32_t compoundStart = index.start;
+    
+    int32_t delta = 0; // delta in length
+
+    // Give each transliterator a crack at the run of characters.
+    // See comments at the top of the method for more detail.
+    for (int32_t i=0; i<count; ++i) {
+        index.start = compoundStart; // Reset start
+        int32_t limit = index.limit;
+        
+        if (index.start == index.limit) {
+            // Short circuit for empty range
+            break;
+        }
+
+        trans[i]->filteredTransliterate(text, index, incremental);
+        
+        // In a properly written transliterator, start == limit after
+        // handleTransliterate() returns when incremental is false.
+        // Catch cases where the subclass doesn't do this, and throw
+        // an exception.  (Just pinning start to limit is a bad idea,
+        // because what's probably happening is that the subclass
+        // isn't transliterating all the way to the end, and it should
+        // in non-incremental mode.)
+        if (!incremental && index.start != index.limit) {
+            // We can't throw an exception, so just fudge things
+            index.start = index.limit;
+        }
+
+        // Cumulative delta for insertions/deletions
+        delta += index.limit - limit;
+        
+        if (incremental) {
+            // In the incremental case, only allow subsequent
+            // transliterators to modify what has already been
+            // completely processed by prior transliterators.  In the
+            // non-incrmental case, allow each transliterator to
+            // process the entire text.
+            index.limit = index.start;
+        }
+    }
+
+    compoundLimit += delta;
+
+    // Start is good where it is -- where the last transliterator left
+    // it.  Limit needs to be put back where it was, modulo
+    // adjustments for deletions/insertions.
+    index.limit = compoundLimit;
+}
+
+/**
+ * Sets the length of the longest context required by this transliterator.
+ * This is <em>preceding</em> context.
+ */
+void CompoundTransliterator::computeMaximumContextLength(void) {
+    int32_t max = 0;
+    for (int32_t i=0; i<count; ++i) {
+        int32_t len = trans[i]->getMaximumContextLength();
+        if (len > max) {
+            max = len;
+        }
+    }
+    setMaximumContextLength(max);
+}
+
+U_NAMESPACE_END
+
+#endif /* #if !UCONFIG_NO_TRANSLITERATION */
+
+/* eof */