X-Git-Url: http://jsfdemo.indexdata.com/?a=blobdiff_plain;f=src%2Ficu_I18N.c;h=f40b529294dd19bd505d38c7a2d853b5418bfbba;hb=f8892da7570d4e365d36d2de128cc581f5240980;hp=b7ba91d8251199bfc186236fd84f3dee85d97424;hpb=4aa097d555372d370f2485df38ddf93ecd327c59;p=pazpar2-moved-to-github.git

diff --git a/src/icu_I18N.c b/src/icu_I18N.c
index b7ba91d..f40b529 100644
--- a/src/icu_I18N.c
+++ b/src/icu_I18N.c
@@ -1,26 +1,24 @@
-/* $Id: icu_I18N.c,v 1.7 2007-05-07 12:52:04 marc Exp $
-   Copyright (c) 2006-2007, Index Data.
+/* This file is part of Pazpar2.
+   Copyright (C) 2006-2008 Index Data
 
-   This file is part of Pazpar2.
+Pazpar2 is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 2, or (at your option) any later
+version.
 
-   Pazpar2 is free software; you can redistribute it and/or modify it under
-   the terms of the GNU General Public License as published by the Free
-   Software Foundation; either version 2, or (at your option) any later
-   version.
+Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
 
-   Pazpar2 is distributed in the hope that it will be useful, but WITHOUT ANY
-   WARRANTY; without even the implied warranty of MERCHANTABILITY or
-   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
-   for more details.
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
-   You should have received a copy of the GNU General Public License
-   along with Pazpar2; see the file LICENSE.  If not, write to the
-   Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-   02111-1307, USA.
 */
 
 #if HAVE_CONFIG_H
-#include "cconfig.h"
+#include <config.h>
 #endif
 
 #define USE_TIMING 0
@@ -55,11 +53,13 @@
 
 int icu_check_status (UErrorCode status)
 {
-    //if(U_FAILURE(status))
-    if(!U_SUCCESS(status))
+    if(U_FAILURE(status)){
         yaz_log(YLOG_WARN, 
                 "ICU: %d %s\n", status, u_errorName(status));
-    return status;
+        return 0;   
+    }
+    return 1;
+    
 }
 
 
@@ -81,7 +81,6 @@ struct icu_buf_utf16 * icu_buf_utf16_create(size_t capacity)
     return buf16;
 };
 
-
 struct icu_buf_utf16 * icu_buf_utf16_resize(struct icu_buf_utf16 * buf16,
                                             size_t capacity)
 {
@@ -109,6 +108,23 @@ struct icu_buf_utf16 * icu_buf_utf16_resize(struct icu_buf_utf16 * buf16,
 };
 
 
+struct icu_buf_utf16 * icu_buf_utf16_copy(struct icu_buf_utf16 * dest16,
+                                          struct icu_buf_utf16 * src16)
+{
+    if(!dest16 || !src16
+       || dest16 == src16)
+        return 0;
+
+    if (dest16->utf16_cap < src16->utf16_len)
+        icu_buf_utf16_resize(dest16, src16->utf16_len * 2);
+
+    u_strncpy(dest16->utf16, src16->utf16, src16->utf16_len);
+    dest16->utf16_len = src16->utf16_len;
+
+    return dest16;
+};
+
+
 void icu_buf_utf16_destroy(struct icu_buf_utf16 * buf16)
 {
     if (buf16){
@@ -151,9 +167,8 @@ struct icu_buf_utf8 * icu_buf_utf8_resize(struct icu_buf_utf8 * buf8,
                 buf8->utf8 = (uint8_t *) malloc(sizeof(uint8_t) * capacity);
             else
                 buf8->utf8 
-                    = (uint8_t *) realloc(buf8->utf8, sizeof(uint8_t) * capacity);
-            buf8->utf8[0] = (uint8_t) 0;
-            buf8->utf8_len = 0;
+                    = (uint8_t *) realloc(buf8->utf8, 
+                                          sizeof(uint8_t) * capacity);
             buf8->utf8_cap = capacity;
         } 
         else { 
@@ -169,6 +184,33 @@ struct icu_buf_utf8 * icu_buf_utf8_resize(struct icu_buf_utf8 * buf8,
 };
 
 
+struct icu_buf_utf8 * icu_buf_utf8_copy(struct icu_buf_utf8 * dest8,
+                                          struct icu_buf_utf8 * src8)
+{
+    if(!dest8 || !src8
+       || dest8 == src8)
+        return 0;
+    
+
+    if (dest8->utf8_cap < src8->utf8_len)
+        icu_buf_utf8_resize(dest8, src8->utf8_len * 2);
+
+    strncpy((char*) dest8->utf8, (char*) src8->utf8, src8->utf8_len);
+
+    return dest8;
+};
+
+
+const char *icu_buf_utf8_to_cstr(struct icu_buf_utf8 *src8)
+{
+    if (!src8 || src8->utf8_len == 0)
+        return "";
+    if (src8->utf8_len == src8->utf8_cap)
+        src8 = icu_buf_utf8_resize(src8, src8->utf8_len * 2 + 1);
+    src8->utf8[src8->utf8_len] = '\0';
+    return (const char *) src8->utf8;
+}
+
 
 void icu_buf_utf8_destroy(struct icu_buf_utf8 * buf8)
 {
@@ -204,7 +246,7 @@ UErrorCode icu_utf16_from_utf8(struct icu_buf_utf16 * dest16,
 
     //if (*status != U_BUFFER_OVERFLOW_ERROR
     if (U_SUCCESS(*status)  
-        && utf16_len < dest16->utf16_cap)
+        && utf16_len <= dest16->utf16_cap)
         dest16->utf16_len = utf16_len;
     else {
         dest16->utf16[0] = (UChar) 0;
@@ -242,7 +284,7 @@ UErrorCode icu_utf16_from_utf8_cstr(struct icu_buf_utf16 * dest16,
 
     //  if (*status != U_BUFFER_OVERFLOW_ERROR
     if (U_SUCCESS(*status)  
-        && utf16_len < dest16->utf16_cap)
+        && utf16_len <= dest16->utf16_cap)
         dest16->utf16_len = utf16_len;
     else {
         dest16->utf16[0] = (UChar) 0;
@@ -279,7 +321,7 @@ UErrorCode icu_utf16_to_utf8(struct icu_buf_utf8 * dest8,
 
     //if (*status != U_BUFFER_OVERFLOW_ERROR
     if (U_SUCCESS(*status)  
-        && utf8_len < dest8->utf8_cap)
+        && utf8_len <= dest8->utf8_cap)
         dest8->utf8_len = utf8_len;
     else {
         dest8->utf8[0] = (uint8_t) 0;
@@ -291,6 +333,51 @@ UErrorCode icu_utf16_to_utf8(struct icu_buf_utf8 * dest8,
 
 
 
+struct icu_casemap * icu_casemap_create(const char *locale, char action,
+                                        UErrorCode *status)
+{    
+    struct icu_casemap * casemap
+        = (struct icu_casemap *) malloc(sizeof(struct icu_casemap));
+    strcpy(casemap->locale, locale);
+    casemap->action = action;
+
+    switch(casemap->action) {    
+    case 'l':   
+        break;
+    case 'u':   
+        break;
+    case 't':  
+        break;
+    case 'f':  
+        break;
+    default:
+        icu_casemap_destroy(casemap);
+        return 0;
+    }
+
+    return casemap;
+};
+
+void icu_casemap_destroy(struct icu_casemap * casemap)
+{
+    if (casemap) 
+        free(casemap);
+};
+
+
+int icu_casemap_casemap(struct icu_casemap * casemap,
+                        struct icu_buf_utf16 * dest16,
+                        struct icu_buf_utf16 * src16,
+                        UErrorCode *status)
+{
+    if(!casemap)
+        return 0;
+    
+    return icu_utf16_casemap(dest16, src16,
+                             casemap->locale, casemap->action, status);
+};
+
+
 int icu_utf16_casemap(struct icu_buf_utf16 * dest16,
                       struct icu_buf_utf16 * src16,
                       const char *locale, char action,
@@ -327,6 +414,7 @@ int icu_utf16_casemap(struct icu_buf_utf16 * dest16,
 
     // check for buffer overflow, resize and retry
     if (*status == U_BUFFER_OVERFLOW_ERROR
+        && dest16 != src16        // do not resize if in-place conversion 
         //|| dest16_len > dest16->utf16_cap
         ){
         icu_buf_utf16_resize(dest16, dest16_len * 2);
@@ -362,7 +450,7 @@ int icu_utf16_casemap(struct icu_buf_utf16 * dest16,
     }
     
     if (U_SUCCESS(*status)
-        && dest16_len < dest16->utf16_cap)
+        && dest16_len <= dest16->utf16_cap)
         dest16->utf16_len = dest16_len;
     else {
         dest16->utf16[0] = (UChar) 0;
@@ -400,7 +488,719 @@ UErrorCode icu_sortkey8_from_utf16(UCollator *coll,
         dest8->utf8_len = 0;
     }
 
-    return *status;
+    return sortkey_len;
+};
+
+
+
+struct icu_tokenizer * icu_tokenizer_create(const char *locale, char action,
+                                            UErrorCode *status)
+{
+    struct icu_tokenizer * tokenizer
+        = (struct icu_tokenizer *) malloc(sizeof(struct icu_tokenizer));
+
+    strcpy(tokenizer->locale, locale);
+    tokenizer->action = action;
+    tokenizer->bi = 0;
+    tokenizer->buf16 = 0;
+    tokenizer->token_count = 0;
+    tokenizer->token_id = 0;
+    tokenizer->token_start = 0;
+    tokenizer->token_end = 0;
+
+
+    switch(tokenizer->action) {    
+    case 'l':
+        tokenizer->bi
+            = ubrk_open(UBRK_LINE, tokenizer->locale,
+                        0, 0, status);
+        break;
+    case 's':
+        tokenizer->bi
+            = ubrk_open(UBRK_SENTENCE, tokenizer->locale,
+                        0, 0, status);
+        break;
+    case 'w':
+        tokenizer->bi 
+            = ubrk_open(UBRK_WORD, tokenizer->locale,
+                        0, 0, status);
+        break;
+    case 'c':
+        tokenizer->bi 
+            = ubrk_open(UBRK_CHARACTER, tokenizer->locale,
+                        0, 0, status);
+        break;
+    case 't':
+        tokenizer->bi 
+            = ubrk_open(UBRK_TITLE, tokenizer->locale,
+                        0, 0, status);
+        break;
+    default:
+        *status = U_UNSUPPORTED_ERROR;
+        return 0;
+        break;
+    }
+    
+    // ICU error stuff is a very  funny business
+    if (U_SUCCESS(*status))
+        return tokenizer;
+
+    // freeing if failed
+    icu_tokenizer_destroy(tokenizer);
+    return 0;
+};
+
+void icu_tokenizer_destroy(struct icu_tokenizer * tokenizer)
+{
+    if (tokenizer) {
+        if (tokenizer->bi)
+            ubrk_close(tokenizer->bi);
+        free(tokenizer);
+    }
+};
+
+int icu_tokenizer_attach(struct icu_tokenizer * tokenizer, 
+                         struct icu_buf_utf16 * src16, 
+                         UErrorCode *status)
+{
+    if (!tokenizer || !tokenizer->bi || !src16)
+        return 0;
+
+
+    tokenizer->buf16 = src16;
+    tokenizer->token_count = 0;
+    tokenizer->token_id = 0;
+    tokenizer->token_start = 0;
+    tokenizer->token_end = 0;
+
+    ubrk_setText(tokenizer->bi, src16->utf16, src16->utf16_len, status);
+    
+ 
+    if (U_FAILURE(*status))
+        return 0;
+
+    return 1;
+};
+
+int32_t icu_tokenizer_next_token(struct icu_tokenizer * tokenizer, 
+                         struct icu_buf_utf16 * tkn16, 
+                         UErrorCode *status)
+{
+    int32_t tkn_start = 0;
+    int32_t tkn_end = 0;
+    int32_t tkn_len = 0;
+    
+
+    if (!tokenizer || !tokenizer->bi
+        || !tokenizer->buf16 || !tokenizer->buf16->utf16_len)
+        return 0;
+
+    // never change tokenizer->buf16 and keep always invariant
+    // 0 <= tokenizer->token_start 
+    //   <= tokenizer->token_end 
+    //   <= tokenizer->buf16->utf16_len
+    // returns length of token
+
+    if (0 == tokenizer->token_end) // first call
+        tkn_start = ubrk_first(tokenizer->bi);
+    else //successive calls
+        tkn_start = tokenizer->token_end;
+
+    // get next position
+    tkn_end = ubrk_next(tokenizer->bi);
+
+    // repairing invariant at end of ubrk, which is UBRK_DONE = -1 
+    if (UBRK_DONE == tkn_end)
+        tkn_end = tokenizer->buf16->utf16_len;
+
+    // copy out if everything is well
+    if(U_FAILURE(*status))
+        return 0;        
+    
+    // everything OK, now update internal state
+    tkn_len = tkn_end - tkn_start;
+
+    if (0 < tkn_len){
+        tokenizer->token_count++;
+        tokenizer->token_id++;
+    } else {
+        tokenizer->token_id = 0;    
+    }
+    tokenizer->token_start = tkn_start;
+    tokenizer->token_end = tkn_end;
+    
+
+    // copying into token buffer if it exists 
+    if (tkn16){
+        if (tkn16->utf16_cap < tkn_len)
+            icu_buf_utf16_resize(tkn16, (size_t) tkn_len * 2);
+
+        u_strncpy(tkn16->utf16, &(tokenizer->buf16->utf16)[tkn_start], 
+                  tkn_len);
+
+        tkn16->utf16_len = tkn_len;
+    }
+
+    return tkn_len;
+}
+
+
+int32_t icu_tokenizer_token_id(struct icu_tokenizer * tokenizer)
+{
+    return tokenizer->token_id;
+};
+
+int32_t icu_tokenizer_token_start(struct icu_tokenizer * tokenizer)
+{
+    return tokenizer->token_start;
+};
+
+int32_t icu_tokenizer_token_end(struct icu_tokenizer * tokenizer)
+{
+    return tokenizer->token_end;
+};
+
+int32_t icu_tokenizer_token_length(struct icu_tokenizer * tokenizer)
+{
+    return (tokenizer->token_end - tokenizer->token_start);
+};
+
+int32_t icu_tokenizer_token_count(struct icu_tokenizer * tokenizer)
+{
+    return tokenizer->token_count;
+};
+
+
+
+struct icu_normalizer * icu_normalizer_create(const char *rules, char action,
+                                              UErrorCode *status)
+{
+
+    struct icu_normalizer * normalizer
+        = (struct icu_normalizer *) malloc(sizeof(struct icu_normalizer));
+
+    normalizer->action = action;
+    normalizer->trans = 0;
+    normalizer->rules16 =  icu_buf_utf16_create(0);
+    icu_utf16_from_utf8_cstr(normalizer->rules16, rules, status);
+     
+    switch(normalizer->action) {    
+    case 'f':
+        normalizer->trans
+            = utrans_openU(normalizer->rules16->utf16, 
+                           normalizer->rules16->utf16_len,
+                           UTRANS_FORWARD,
+                           0, 0, 
+                           normalizer->parse_error, status);
+        // yaz_log(YLOG_LOG, "utrans_open %p", normalizer->trans);
+        break;
+    case 'r':
+        normalizer->trans
+            = utrans_openU(normalizer->rules16->utf16,
+                           normalizer->rules16->utf16_len,
+                           UTRANS_REVERSE ,
+                           0, 0,
+                           normalizer->parse_error, status);
+        // yaz_log(YLOG_LOG, "utrans_open %p", normalizer->trans);
+        break;
+    default:
+        *status = U_UNSUPPORTED_ERROR;
+        return 0;
+        break;
+    }
+    
+    if (U_SUCCESS(*status))
+        return normalizer;
+
+    // freeing if failed
+    icu_normalizer_destroy(normalizer);
+    return 0;
+};
+
+
+void icu_normalizer_destroy(struct icu_normalizer * normalizer){
+    if (normalizer) {
+        if (normalizer->rules16) 
+            icu_buf_utf16_destroy(normalizer->rules16);
+        if (normalizer->trans)
+        {
+            // yaz_log(YLOG_LOG, "utrans_close %p", normalizer->trans);
+            utrans_close(normalizer->trans);
+        }
+        free(normalizer);
+    }
+};
+
+
+
+int icu_normalizer_normalize(struct icu_normalizer * normalizer,
+                             struct icu_buf_utf16 * dest16,
+                             struct icu_buf_utf16 * src16,
+                             UErrorCode *status)
+{
+    if (!normalizer || !normalizer->trans || !src16 || !dest16)
+        return 0;
+
+    if (!icu_buf_utf16_copy(dest16, src16))
+        return 0;
+
+    utrans_transUChars (normalizer->trans, 
+                        dest16->utf16, &(dest16->utf16_len),
+                        dest16->utf16_cap,
+                        0, &(src16->utf16_len), status);
+
+    if (U_FAILURE(*status)){
+        dest16->utf16[0] = (UChar) 0;
+        dest16->utf16_len = 0;
+    }
+    
+    return dest16->utf16_len;
+}
+
+
+
+
+struct icu_chain_step * icu_chain_step_create(struct icu_chain * chain,
+                                              enum icu_chain_step_type type,
+                                              const uint8_t * rule,
+                                              struct icu_buf_utf16 * buf16,
+                                              UErrorCode *status)
+{
+    struct icu_chain_step * step = 0;
+    
+    if(!chain || !type || !rule)
+        return 0;
+
+    step = (struct icu_chain_step *) malloc(sizeof(struct icu_chain_step));
+
+    step->type = type;
+
+    step->buf16 = buf16;
+
+    // create auxilary objects
+    switch(step->type) {
+    case ICU_chain_step_type_display:
+        break;
+    case ICU_chain_step_type_index:
+        break;
+    case ICU_chain_step_type_sortkey:
+        break;
+    case ICU_chain_step_type_casemap:
+        step->u.casemap = icu_casemap_create((char *) chain->locale, 
+                                             (char) rule[0], status);
+        break;
+    case ICU_chain_step_type_normalize:
+        step->u.normalizer = icu_normalizer_create((char *) rule, 'f', status);
+        break;
+    case ICU_chain_step_type_tokenize:
+        step->u.tokenizer = icu_tokenizer_create((char *) chain->locale, 
+                                                 (char) rule[0], status);
+        break;
+    default:
+        break;
+    }
+
+    return step;
+};
+
+
+void icu_chain_step_destroy(struct icu_chain_step * step){
+    
+    if (!step)
+        return;
+
+    icu_chain_step_destroy(step->previous);
+
+    switch(step->type) {
+    case ICU_chain_step_type_display:
+        break;
+    case ICU_chain_step_type_index:
+        break;
+    case ICU_chain_step_type_sortkey:
+        break;
+    case ICU_chain_step_type_casemap:
+        icu_casemap_destroy(step->u.casemap);
+        icu_buf_utf16_destroy(step->buf16);
+        break;
+    case ICU_chain_step_type_normalize:
+        icu_normalizer_destroy(step->u.normalizer);
+        icu_buf_utf16_destroy(step->buf16);
+        break;
+    case ICU_chain_step_type_tokenize:
+        icu_tokenizer_destroy(step->u.tokenizer);
+        icu_buf_utf16_destroy(step->buf16);
+        break;
+    default:
+        break;
+    }
+    free(step);
+};
+
+
+
+struct icu_chain * icu_chain_create(const uint8_t * identifier,
+                                    const uint8_t * locale)
+{
+
+    struct icu_chain * chain 
+        = (struct icu_chain *) malloc(sizeof(struct icu_chain));
+
+    strncpy((char *) chain->identifier, (const char *) identifier, 128);
+    chain->identifier[128 - 1] = '\0';
+    strncpy((char *) chain->locale, (const char *) locale, 16);    
+    chain->locale[16 - 1] = '\0';
+
+    chain->token_count = 0;
+
+    chain->display8 = icu_buf_utf8_create(0);
+    chain->norm8 = icu_buf_utf8_create(0);
+    chain->sort8 = icu_buf_utf8_create(0);
+
+    chain->src16 = icu_buf_utf16_create(0);
+
+    chain->steps = 0;
+
+    return chain;
+};
+
+
+void icu_chain_destroy(struct icu_chain * chain)
+{
+    if (chain){
+        icu_buf_utf8_destroy(chain->display8);
+        icu_buf_utf8_destroy(chain->norm8);
+        icu_buf_utf8_destroy(chain->sort8);
+        
+        icu_buf_utf16_destroy(chain->src16);
+    
+        icu_chain_step_destroy(chain->steps);
+        free(chain);
+    }
+};
+
+
+
+struct icu_chain * icu_chain_xml_config(xmlNode *xml_node, 
+                                        UErrorCode * status){
+
+    xmlNode *node = 0;
+    struct icu_chain * chain = 0;
+    xmlChar *xml_id = 0;
+    xmlChar *xml_locale = 0;
+   
+    if (!xml_node 
+        ||xml_node->type != XML_ELEMENT_NODE 
+        || strcmp((const char *) xml_node->name, "icu_chain"))
+
+        return 0;
+    
+    xml_id = xmlGetProp(xml_node, (xmlChar *) "id");
+    xml_locale = xmlGetProp(xml_node, (xmlChar *) "locale");
+
+    if (!xml_id || !strlen((const char *) xml_id) 
+        || !xml_locale || !strlen((const char *) xml_locale))
+        return 0;
+
+    chain = icu_chain_create((const uint8_t *) xml_id, 
+                             (const uint8_t *) xml_locale);
+    
+    xmlFree(xml_id);
+    xmlFree(xml_locale);
+    if (!chain)
+        return 0;
+        
+    for (node = xml_node->children; node; node = node->next)
+    {
+        xmlChar *xml_rule = 0;
+        struct icu_chain_step * step = 0;
+        if (node->type != XML_ELEMENT_NODE)
+            continue;
+
+        xml_rule = xmlGetProp(node, (xmlChar *) "rule");
+
+        if (!strcmp((const char *) node->name, 
+                    (const char *) "casemap")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_casemap, 
+                                         (const uint8_t *) xml_rule, status);
+        }
+        else if (!strcmp((const char *) node->name,
+                         (const char *) "normalize")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_normalize, 
+                                         (const uint8_t *) xml_rule, status);
+        }
+        else if (!strcmp((const char *) node->name,
+                         (const char *) "tokenize")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_tokenize, 
+                                         (const uint8_t *) xml_rule, status);
+        }
+        else if (!strcmp((const char *) node->name,
+                         (const char *) "display")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_display, 
+                                         (const uint8_t *) "", status);
+        }
+        else if (!strcmp((const char *) node->name,
+                         (const char *) "index")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_index, 
+                                         (const uint8_t *) "", status);
+        }
+        else if (!strcmp((const char *) node->name,
+                         (const char *) "sortkey")){
+            step = icu_chain_insert_step(chain, ICU_chain_step_type_sortkey, 
+                                         (const uint8_t *) "", status);
+        }
+
+        xmlFree(xml_rule);
+        if (!step || U_FAILURE(*status)){
+            icu_chain_destroy(chain);
+            return 0;
+        }
+        
+
+    }
+
+    return chain;
+};
+
+
+
+struct icu_chain_step * icu_chain_insert_step(struct icu_chain * chain,
+                                              enum icu_chain_step_type type,
+                                              const uint8_t * rule,
+                                              UErrorCode *status)
+{    
+    struct icu_chain_step * step = 0;
+    struct icu_buf_utf16 * src16 = 0;
+    struct icu_buf_utf16 * buf16 = 0;
+
+    if (!chain || !type || !rule)
+        return 0;
+
+    // assign utf16 src buffers as needed 
+    if (chain->steps && chain->steps->buf16)
+        src16 = chain->steps->buf16;
+    else if (chain->src16)
+        src16 = chain->src16;
+    else
+        return 0;
+
+    
+    // create utf16 destination buffers as needed, or
+    switch(type) {
+    case ICU_chain_step_type_display:
+        buf16 = src16;
+        break;
+    case ICU_chain_step_type_index:
+        buf16 = src16;
+        break;
+    case ICU_chain_step_type_sortkey:
+        buf16 = src16;
+        break;
+    case ICU_chain_step_type_casemap:
+        buf16 = icu_buf_utf16_create(0);
+        break;
+    case ICU_chain_step_type_normalize:
+        buf16 = icu_buf_utf16_create(0);
+        break;
+    case ICU_chain_step_type_tokenize:
+        buf16 = icu_buf_utf16_create(0);
+        break;
+    default:
+        break;
+    }
+
+    // create actual chain step with this buffer
+    step = icu_chain_step_create(chain, type, rule, buf16, status);
+
+    step->previous = chain->steps;
+    chain->steps = step;
+
+    return step;
+};
+
+
+int icu_chain_step_next_token(struct icu_chain * chain,
+                              struct icu_chain_step * step,
+                              UErrorCode *status)
+{
+    struct icu_buf_utf16 * src16 = 0;
+    
+    //printf("icu_chain_step_next_token %d\n", (int) step);
+
+    if (!chain || !chain->src16 || !step || !step->more_tokens)
+        return 0;
+
+    // assign utf16 src buffers as neeed, advance in previous steps
+    // tokens until non-zero token met, and setting stop condition
+    if (step->previous){
+        src16 = step->previous->buf16;
+        if (step->need_new_token)
+            //while (step->more_tokens &&  !src16->utf16_len)
+                step->more_tokens 
+                    = icu_chain_step_next_token(chain, step->previous, status);
+    }
+    else { // first step can only work once on chain->src16 input buffer
+        src16 = chain->src16;
+        step->more_tokens = 1;
+    }
+
+    // stop if nothing to process 
+    // i.e new token source was not properly assigned
+    if (!step->more_tokens || !src16) // || !src16->utf16_len 
+        return 0;
+
+    //printf("icu_chain_step_next_token %d working\n", (int) step);
+
+
+    // perform the work, eventually put this steps output in 
+    // step->buf16 or the chains UTF8 output buffers 
+    switch(step->type) {
+    case ICU_chain_step_type_display:
+        icu_utf16_to_utf8(chain->display8, src16, status);
+        break;
+    case ICU_chain_step_type_index:
+        icu_utf16_to_utf8(chain->norm8, src16, status);
+        break;
+    case ICU_chain_step_type_sortkey:
+        icu_utf16_to_utf8(chain->sort8, src16, status);
+        break;
+    case ICU_chain_step_type_casemap:
+        icu_casemap_casemap(step->u.casemap,
+                            step->buf16, src16, status);
+        break;
+    case ICU_chain_step_type_normalize:
+        icu_normalizer_normalize(step->u.normalizer,
+                                 step->buf16, src16, status);
+        break;
+    case ICU_chain_step_type_tokenize:
+        // attach to new src16 token only first time during splitting
+        if (step->need_new_token){
+            icu_tokenizer_attach(step->u.tokenizer, src16, status);
+            step->need_new_token = 0;
+        }
+        // splitting one src16 token into multiple buf16 tokens
+        step->more_tokens
+            = icu_tokenizer_next_token(step->u.tokenizer,
+                                       step->buf16, status);
+        // make sure to get new previous token if this one had been used up
+        if (step->previous && !step->more_tokens){
+            if (icu_chain_step_next_token(chain, step->previous, status)){
+                icu_tokenizer_attach(step->u.tokenizer, src16, status);
+                step->need_new_token = 0;   
+                step->more_tokens
+                    = icu_tokenizer_next_token(step->u.tokenizer,
+                                               step->buf16, status);
+            }
+        }
+        if (0 == step->more_tokens)
+            return 0;
+        break;
+    default:
+        return 0;
+        break;
+    }
+
+
+
+    // stop further token processing if last step and 
+    // new tokens are needed from previous (non-existing) step
+    if (!step->previous && step->need_new_token)
+        step->more_tokens = 0;
+
+    //printf("%d %d %d\n", 
+    //       step->more_tokens, src16->utf16_len, step->buf16->utf16_len);
+
+
+    if (U_FAILURE(*status))
+        return 0;
+
+    return 1;
+};
+
+
+
+int icu_chain_assign_cstr(struct icu_chain * chain,
+                          const char * src8cstr, 
+                          UErrorCode *status)
+{
+    struct icu_chain_step * stp = 0; 
+
+    if (!chain || !src8cstr)
+        return 0;
+
+    stp = chain->steps;
+    
+    // clear token count
+    chain->token_count = 0;
+
+    // clear all steps stop states
+
+    while (stp){
+        stp->more_tokens = 1;
+        stp->need_new_token = 1;
+        stp = stp->previous;
+    }
+    
+    // finally convert UTF8 to UTF16 string
+    icu_utf16_from_utf8_cstr(chain->src16, src8cstr, status);
+            
+    if (U_FAILURE(*status))
+        return 0;
+
+    return 1;
+};
+
+
+
+int icu_chain_next_token(struct icu_chain * chain,
+                         UErrorCode *status)
+{
+    int success = 0;
+    
+    if (!chain || !chain->steps)
+        return 0;
+
+    success = icu_chain_step_next_token(chain, chain->steps, status);
+    
+    if (success){
+        chain->token_count++;
+        return chain->token_count;
+    }
+
+    return 0;
+};
+
+int icu_chain_get_token_count(struct icu_chain * chain)
+{
+    if (!chain)
+        return 0;
+    
+    return chain->token_count;
+};
+
+
+
+const char * icu_chain_get_display(struct icu_chain * chain)
+{
+    if (chain->display8)
+        return icu_buf_utf8_to_cstr(chain->display8);
+    
+    return 0;
+};
+
+const char * icu_chain_get_norm(struct icu_chain * chain)
+{
+    if (chain->norm8)
+        return icu_buf_utf8_to_cstr(chain->norm8);
+    
+    return 0;
+};
+
+const char * icu_chain_get_sort(struct icu_chain * chain)
+{
+    if (chain->sort8)
+        return icu_buf_utf8_to_cstr(chain->sort8);
+    
+    return 0;
 };