--- parser3/src/main/pa_string.C	2001/04/23 13:38:31	1.78
+++ parser3/src/main/pa_string.C	2012/06/20 21:01:20	1.243
@@ -1,588 +1,1002 @@
 /** @file
-	Parser: string class. @see untasize_t.C.
+	Parser: string class. @see untalength_t.C.
 
-	Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
-
-	Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
-
-	$Id: pa_string.C,v 1.78 2001/04/23 13:38:31 paf Exp $
+	Copyright (c) 2001-2012 Art. Lebedev Studio (http://www.artlebedev.com)
+	Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
 */
 
-#include "pa_config_includes.h"
-
-#include "pcre.h"
-
-#include "pa_pool.h"
 #include "pa_string.h"
-#include "pa_hash.h"
 #include "pa_exception.h"
-#include "pa_common.h"
-#include "pa_array.h"
-#include "pa_globals.h"
 #include "pa_table.h"
-#include "pa_threads.h"
+#include "pa_dictionary.h"
+#include "pa_charset.h"
+#include "pa_vregex.h"
+
+volatile const char * IDENT_PA_STRING_C="$Id: pa_string.C,v 1.243 2012/06/20 21:01:20 moko Exp $" IDENT_PA_STRING_H;
+
+const String String::Empty;
+
+
+// pa_atoui is based on Manuel Novoa III _strto_l for uClibc
+
+unsigned int pa_atoui(const char *str, int base, const String* problem_source){
+	unsigned int result = 0;
+	const char *pos = str;
+
+	while (isspace(*pos)) /* skip leading whitespace */
+		++pos;
+
+	if (base == 16 && *pos == '0') { /* handle option prefix */
+		++pos;
+		if (*pos == 'x' || *pos == 'X') {
+			++pos;
+		}
+	}
+
+	if (base == 0) { /* dynamic base */
+		base = 10; /* default is 10 */
+		if (*pos == '0') {
+			++pos;
+			if (*pos == 'x' || *pos == 'X')
+				++pos;
+				base=16;
+		}
+	}
+
+	if (base < 2 || base > 16) { /* illegal base */
+		throw Exception(PARSER_RUNTIME, 0, "base to must be an integer from 2 to 16");
+	}
 
-//#include "pa_sapi.h"
+	unsigned int cutoff = UINT_MAX / base;
+	int cutoff_digit = UINT_MAX - cutoff * base;
 
-// String
+	while(true) {
+		int digit;
+		
+		if ((*pos >= '0') && (*pos <= '9')) {
+			digit = (*pos - '0');
+		} else if (*pos >= 'a') {
+			digit = (*pos - 'a' + 10);
+		} else if (*pos >= 'A') {
+			digit = (*pos - 'A' + 10);
+		} else break;
 
-String::String(Pool& apool, const char *src, size_t src_size, bool tainted) :
-	Pooled(apool) {
-	last_chunk=&head;
-	head.count=CR_PREALLOCATED_COUNT;
-	append_here=head.rows;
-	head.preallocated_link=0;
-	link_row=&head.rows[head.count];
-	fused_rows=fsize=0;
-
-	if(src)
-		if(tainted)
-			APPEND_TAINTED(src, src_size, 0, 0);
-		else
-			APPEND_CLEAN(src, src_size, 0, 0);
-}
-
-void String::expand() {
-	size_t new_chunk_count=last_chunk->count+last_chunk->count*CR_GROW_PERCENT/100;
-	last_chunk=static_cast<Chunk *>(
-		malloc(sizeof(size_t)+sizeof(Chunk::Row)*new_chunk_count+sizeof(Chunk *)));
-	last_chunk->count=new_chunk_count;
-	link_row->link=last_chunk;
-	append_here=last_chunk->rows;
-	link_row=&last_chunk->rows[last_chunk->count];
-	link_row->link=0;
+		if (digit >= base) {
+			break;
+		}
+		
+		++pos;
+		
+		/* adjust number, with overflow check */
+		if ((result > cutoff) || ((result == cutoff) && (digit > cutoff_digit))) {
+			throw Exception("number.format", problem_source, problem_source ? "out of range (int)" : "'%s' is out of range (int)", str);
+		} else {
+			result  = result * base + digit;
+		}
+	}
+
+	while(char c=*pos++)
+		if(!isspace(c))
+			throw Exception("number.format", problem_source, problem_source ? "invalid number (int)" : "'%s' is invalid number (int)", str);
+
+	return result;
 }
 
-String::String(const String& src) :	Pooled(src.pool()) {
-	head.count=CR_PREALLOCATED_COUNT;
+int pa_atoi(const char* str, const String* problem_source) {
+	if(!str)
+		return 0;
+
+	while(isspace(*str))
+		str++;
+
+	if(!*str)
+		return 0;
+
+	bool negative=false;
+	if(str[0]=='-') {
+		negative=true;
+		str++;
+	} else if(str[0]=='+') {
+		str++;
+	}
+
+	unsigned int result=pa_atoui(str, 0, problem_source);
+
+	if(negative && result <= ((unsigned int)(-(1+INT_MIN)))+1)
+		return -(int)result;
 	
-	size_t src_used_rows=src.fused_rows;
-	if(src_used_rows<=head.count) {
-		// all new rows fit size_to preallocated area
-		size_t curr_chunk_rows=head.count;
-		memcpy(head.rows, src.head.rows, sizeof(Chunk::Row)*src_used_rows);
-		append_here=&head.rows[src_used_rows];
-		link_row=&head.rows[curr_chunk_rows];
-	} else {
-		// warning: 
-		//   heavily relies on the fact 
-		//   "preallocated area is the same for all strings"
-		//
-		// info:
-		//   allocating only enough mem to fit src string rows
-		//   next append would allocate a new chunk
-		//
-		// new rows don't fit size_to preallocated area: splitting size_to two chunks
-		// preallocated chunk src to constructing head
-		memcpy(head.rows, src.head.rows, sizeof(Chunk::Row)*head.count);
-		// remaining rows size_to new_chunk
-		size_t curr_chunk_rows=src_used_rows-head.count;
-		Chunk *new_chunk=static_cast<Chunk *>(
-			malloc(sizeof(size_t)+sizeof(Chunk::Row)*curr_chunk_rows+sizeof(Chunk *)));
-		new_chunk->count=curr_chunk_rows;
-		head.preallocated_link=new_chunk;
-		append_here=link_row=&new_chunk->rows[new_chunk->count];
-
-		Chunk *old_chunk=src.head.preallocated_link; 
-		Chunk::Row *new_rows=new_chunk->rows;
-		size_t rows_left_to_copy=new_chunk->count;
-		while(true) {
-			size_t old_count=old_chunk->count;
-			Chunk *next_chunk=old_chunk->rows[old_count].link;
-			if(next_chunk) {
-				// not last source chunk
-				// taking it all
-				memcpy(new_rows, old_chunk->rows, sizeof(Chunk::Row)*old_count);
-				new_rows+=old_count;
-				rows_left_to_copy-=old_count;
-
-				old_chunk=next_chunk;
-			} else {
-				// the last source chunk
-				// taking only those rows of chunk that _left_to_copy
-				memcpy(new_rows, old_chunk->rows, sizeof(Chunk::Row)*rows_left_to_copy);
-				break;
-			}
-		}
+	if(result<=INT_MAX)
+		return (int)result;
+	
+	throw Exception("number.format", problem_source, problem_source ? "out of range (int)" : "'%s' is out of range (int)", str);
+}
+
+double pa_atod(const char* str, const String* problem_source) {
+	if(!str)
+		return 0;
+
+	while(isspace(*str))
+		str++;
+
+	if(!*str)
+		return 0;
+
+	bool negative=false;
+	if(str[0]=='-') {
+		negative=true;
+		str++;
+	} else if(str[0]=='+') {
+		str++;
 	}
-	link_row->link=0;
-	fused_rows=src_used_rows;
-	fsize=src.fsize;
-}
-
-String& String::append(const String& src, Untaint_lang lang, bool forced) {
-	const Chunk *chunk=&src.head; 
-	do {
-		const Chunk::Row *row=chunk->rows;
-		for(size_t i=0; i<chunk->count; i++, row++) {
-			if(row==src.append_here)
-				goto break2;
-			
-			APPEND(row->item.ptr, row->item.size, 
-				(lang!=UL_PASS_APPENDED && (row->item.lang==UL_TAINTED || forced))?lang:row->item.lang,
-				row->item.origin.file, row->item.origin.line);
-		}
-		chunk=row->link;
-	} while(chunk);
-break2:
-	return *this;
+
+	double result;
+	if(str[0]=='0')
+		if(str[1]=='x' || str[1]=='X'){
+			// 0xABC
+			result=(double)pa_atoui(str, 0, problem_source);
+			return negative ? -result : result;
+		} else {
+			 // skip leading 0000, to disable octal interpretation
+			do str++; while(*str=='0');
+		}
+
+	char *error_pos;
+	result=strtod(str, &error_pos);
+
+	while(char c=*error_pos++)
+		if(!isspace((unsigned char)c))
+			throw Exception("number.format", problem_source, problem_source ? "invalid number (double)" : "'%s' is invalid number (double)", str);
+
+	return negative ? -result : result;
 }
 
-String& String::real_append(STRING_APPEND_PARAMS) {
-	if(!src)
-		return *this;
-	if(!size)
-		size=strlen(src);
-	if(!size)
-		return *this;
-
-	if(chunk_is_full())
-		expand();
-
-	append_here->item.ptr=src;
-	fsize+=append_here->item.size=size;
-	append_here->item.lang=lang;
-#ifndef NO_STRING_ORIGIN
-	append_here->item.origin.file=file;
-	append_here->item.origin.line=line;
+// cord lib extension
+
+#ifndef DOXYGEN
+typedef struct {
+    ssize_t countdown;
+    int target;	/* Character we're looking for	*/
+} chr_data;
 #endif
-	append_here++; fused_rows++;
+static int CORD_range_contains_chr_greater_then_proc(char c, size_t size, void* client_data)
+{
+    register chr_data * d = (chr_data *)client_data;
+    
+    if (d -> countdown<=0) return(2);
+    d -> countdown -= size;
+    if (c > d -> target) return(1);
+    return(0);
+}
+int CORD_range_contains_chr_greater_then(CORD x, size_t i, size_t n, int c)
+{
+    chr_data d;
 
-	return *this;
+    d.countdown = n;
+    d.target = c;
+    return(CORD_block_iter(x, i, CORD_range_contains_chr_greater_then_proc, &d) == 1/*alternatives: 0 normally ended, 2=struck 'n'*/);
 }
 
-uint String::hash_code() const {
-	uint result=0;
+static int CORD_block_count_proc(char /*c*/, size_t /*size*/, void* client_data)
+{
+    int* result=(int*)client_data;
+    (*result)++;
+    return(0); // 0=continue
+}
+size_t CORD_block_count(CORD x)
+{
+	size_t result=0;
+	CORD_block_iter(x, 0, CORD_block_count_proc, &result);
+    return result;
+}
 
-	const Chunk *chunk=&head; 
-	do {
-		const Chunk::Row *row=chunk->rows;
-		for(size_t i=0; i<chunk->count; i++) {
-			if(row==append_here)
-				goto break2;
-
-			result=Hash::generic_code(result, row->item.ptr, row->item.size);
-			row++;
-		}
-		chunk=row->link;
-	} while(chunk);
-break2:
-	return result;
+// helpers
+
+/// String::match uses this as replace & global search table columns
+
+const int MAX_MATCH_GROUPS=100;
+
+class String_match_table_template_columns: public ArrayString {
+public:
+	String_match_table_template_columns() {
+		*this+=new String("prematch");
+		*this+=new String("match");
+		*this+=new String("postmatch");
+		for(int i=0; i<MAX_MATCH_GROUPS; i++) {
+			*this+=new String(String::Body::Format(1+i), String::L_CLEAN);
+		}
+	}
+};
+
+Table string_match_table_template(new String_match_table_template_columns);
+
+// String::Body methods
+
+String::Body String::Body::Format(int value) {
+	char local[MAX_NUMBER];
+	size_t length=snprintf(local, MAX_NUMBER, "%d", value);
+	return String::Body(pa_strdup(local, length));
 }
 
-/// @todo move 'lang' skipping to pos
-int String::cmp(int& partial, const String& src, 
-				size_t this_offset, Untaint_lang lang) const {
-	partial=-1;
-	this_offset=min(this_offset, size()-1);
-
-	const Chunk *a_chunk=&head;
-	const Chunk *b_chunk=&src.head;
-	const Chunk::Row *a_row=a_chunk->rows;
-	const Chunk::Row *b_row=b_chunk->rows;
-	size_t a_offset=this_offset;
-	size_t b_offset=0;
-	Chunk::Row *a_end=append_here;
-	Chunk::Row *b_end=src.append_here;
-	size_t a_countdown=a_chunk->count;
-	size_t b_countdown=b_chunk->count;
-	bool a_break=false;
-	bool b_break=false;
-	size_t result;
-	size_t pos=0; 
-	while(true) {
-		a_break=a_row==a_end;
-		b_break=b_row==b_end;
-		if(a_break || b_break)
-			break;
+String::Body String::Body::trim(String::Trim_kind kind, const char* chars, 
+								size_t* out_start, size_t* out_length, Charset* source_charset) const {
+	size_t our_length=length();
+	if(!our_length)
+		return *this;
 
-		if(pos+a_row->item.size > this_offset) {
-			if(lang!=UL_UNSPECIFIED && a_row->item.lang!=lang) 
-				return -1; // wrong lang -- bail out
-
-			int size_diff=
-				(a_row->item.size-a_offset)-
-				(b_row->item.size-b_offset);
-			
-			if(size_diff==0) { // a has same size as b
-				result=memcmp(a_row->item.ptr+a_offset, b_row->item.ptr+b_offset, 
-					a_row->item.size-a_offset);
-				if(result)
-					return result;
-				pos+=a_row->item.size;
-				a_row++; a_countdown--; a_offset=0;
-				b_row++; b_countdown--; b_offset=0;
-			} else if (size_diff>0) { // a longer
-				result=memcmp(a_row->item.ptr+a_offset, b_row->item.ptr+b_offset, 
-					b_row->item.size-b_offset);
-				if(result)
-					return result;
-				a_offset+=b_row->item.size-b_offset;
-				b_row++; b_countdown--; b_offset=0;
-			} else { // b longer
-				result=memcmp(a_row->item.ptr+a_offset, b_row->item.ptr+b_offset, 
-					a_row->item.size-a_offset);
-				if(result)
-					return result;
-				b_offset+=a_row->item.size-a_offset;
-				pos+=a_row->item.size;
-				a_row++; a_countdown--; a_offset=0;
+	// check if any UTF-8 in chars
+	bool fast=true;
+	if(chars && source_charset && source_charset->isUTF8()){
+		const char* pos=chars;
+		while(unsigned char c=*pos++)
+			if(c>127){
+				fast=false;
+				break;
 			}
-			
-			if(!b_countdown) {
-				b_chunk=b_row->link;
-				b_row=b_chunk->rows;
-				b_countdown=b_chunk->count;
+	}
+
+	size_t start=0;
+	size_t end=our_length;
+	if(!chars)
+		chars=" \t\n"; // white space
+
+	if(fast){
+		// from left...
+		if(kind!=TRIM_END) {
+			CORD_pos pos; set_pos(pos, 0);
+			while(true) {
+				char c=CORD_pos_fetch(pos);
+				if(strchr(chars, c)) {
+					if(++start==our_length)
+						return 0; // all chars are empty, just return empty string
+				} else
+					break;			
+
+				CORD_next(pos);
+			}
+		}
+
+		// from right..
+		if(kind!=TRIM_START) {
+			CORD_pos pos; set_pos(pos, end-1);
+			while(true) {
+				char c=CORD_pos_fetch(pos);
+				if(strchr(chars, c)) {
+					if(--end==0) // optimization: NO need to check for 'end>=start', that's(<) impossible
+						return 0; // all chars are empty, just return empty string
+				} else
+					break;			
+
+				CORD_prev(pos);
+			}
+		}
+	} else {
+		const XMLByte* src_begin=(const XMLByte*)cstr();
+		const XMLByte* src_end=src_begin+our_length;
+
+		// from left...
+		if(kind!=TRIM_END) {
+			while(src_begin<src_end){
+				uint char_length=1;
+				const XMLByte* ptr=src_begin;
+				// searching first UTF-8 byte: http://tools.ietf.org/html/rfc3629#section-3
+				while(++src_begin<=src_end && (*src_begin>127 && *src_begin<0xC0))
+					char_length++;
+
+				bool found=false;
+				for(const char* chars_byte=chars; chars_byte=strchr(chars_byte, *ptr); chars_byte++)
+					if(strncmp(chars_byte, (const char*)ptr, char_length)==0){
+						found=true;
+						break;
+					}
+
+				if(found){
+					start+=char_length;
+					if(start==our_length)
+						return 0; // all chars are empty, just return empty string
+				} else
+					break;
 			}
-		} else {
-			a_offset-=a_row->item.size;
-			pos+=a_row->item.size;
-			a_row++; a_countdown--; 
 		}
 
-		if(!a_countdown) {
-			a_chunk=a_row->link;
-			a_row=a_chunk->rows;
-			a_countdown=a_chunk->count;
+		// from right..
+		if(kind!=TRIM_START) {
+			while(src_begin<src_end){
+				uint char_length=1;
+				// searching first UTF-8 byte: http://tools.ietf.org/html/rfc3629#section-3
+				while(src_begin<=--src_end && (*src_end>127 && *src_end<0xC0))
+					char_length++;
+
+				bool found=false;
+				for(const char* chars_byte=chars; chars_byte=strchr(chars_byte, *src_end); chars_byte++)
+					if(strncmp(chars_byte, (const char*)src_end, char_length)==0){
+						found=true;
+						break;
+					}
+
+				if(found){
+					end-=char_length;
+					if(end==0)
+						return 0; // all chars are empty, just return empty string
+				} else
+					break;
+			}
 		}
 	}
-	if(a_break==b_break) { // ended simultaneously
-		partial=0; return 0;
-	} else if(a_break) { // first bytes equal, but a ended before b
-		partial=1; return -1;
+
+	if(start==0 && end==our_length) // nobody moved a thing
+		return *this;
+
+	if(out_start)
+		*out_start=start;
+	size_t new_length=end-start;
+	if(out_length)
+		*out_length=new_length;
+
+	return mid(start, new_length);
+}
+
+static int CORD_batched_iter_fn_generic_hash_code(char c, void * client_data) {
+	uint& result=*static_cast<uint*>(client_data);
+	generic_hash_code(result, c);
+	return 0;
+}
+static int CORD_batched_iter_fn_generic_hash_code(const char*  s, void * client_data) {
+	uint& result=*static_cast<uint*>(client_data);
+	generic_hash_code(result, s);
+	return 0;
+};
+uint String::Body::get_hash_code() const {
+#ifdef HASH_CODE_CACHING
+	if(hash_code)
+		return hash_code;
+#else
+	uint hash_code=0;
+#endif
+	if (body && CORD_IS_STRING(body)){
+		generic_hash_code(hash_code, body);
 	} else {
-		partial=2; return +1;
+		CORD_iter5(body, 0,
+			CORD_batched_iter_fn_generic_hash_code, 
+			CORD_batched_iter_fn_generic_hash_code, &hash_code);
 	}
+	return hash_code;
 }
 
-/// @todo move 'lang' skipping to pos
-int String::cmp(int& partial, const char* b_ptr, size_t src_size, 
-				size_t this_offset, Untaint_lang lang) const {
-	partial=-1;
-	size_t b_size=src_size?src_size:b_ptr?strlen(b_ptr):0;
-	this_offset=min(this_offset, size()-1);
-
-	const Chunk *a_chunk=&head;
-	const Chunk::Row *a_row=a_chunk->rows;
-	size_t a_offset=this_offset;
-	size_t b_offset=0;
-	Chunk::Row *a_end=append_here;
-	size_t a_countdown=a_chunk->count;
-	bool a_break=false;
-	bool b_break=false;
-	size_t pos=0;
-	while(true) {
-		a_break=a_row==a_end;
-		if(a_break || b_break)
-			break;
+struct CORD_pos_info {
+	const char* chars;
+	size_t left;
+	size_t pos;
+};
 
-		if(pos+a_row->item.size > this_offset) {
-			if(lang!=UL_UNSPECIFIED && a_row->item.lang!=lang) 
-				return -1; // wrong lang -- bail out
-
-			int size_diff=
-				(a_row->item.size-a_offset)-
-				(b_size-b_offset);
-			
-			if(size_diff==0) { // a has same size as b
-				if(size_t result=memcmp(a_row->item.ptr+a_offset, b_ptr+b_offset, 
-					a_row->item.size-a_offset)!=0)
-					return result;
-				pos+=a_row->item.size;
-				a_row++; a_countdown--; a_offset=0;
-				b_break=true;
-			} else if (size_diff>0) { // a longer
-				if(size_t result=memcmp(a_row->item.ptr+a_offset, b_ptr+b_offset, 
-					b_size-b_offset)!=0)
-					return result;
-				a_offset+=b_size-b_offset;
-				b_break=true;
-			} else { // b longer
-				if(size_t result=memcmp(a_row->item.ptr+a_offset, b_ptr+b_offset, 
-					a_row->item.size-a_offset)!=0)
-					return result;
-				b_offset+=a_row->item.size-a_offset;
-				pos+=a_row->item.size;
-				a_row++; a_countdown--; a_offset=0;
-			}
-		} else {
-			a_offset-=a_row->item.size; 
-			pos+=a_row->item.size;
-			a_row++; a_countdown--; 
-		}
+// can be called only for IS_FUNCTION(CORD) which is used in String::Body::strrpbrk
+static int CORD_iter_fn_rpos(char c, CORD_pos_info* info) {
+	if(info->pos < info->left){
+		info->pos=STRING_NOT_FOUND;
+		return 1;
+	}
+	if(strchr(info->chars, c))
+		return 1;
+	--(info->pos);
+	return 0;
+}
 
-		if(!a_countdown) {
-			a_chunk=a_row->link;
-			a_row=a_chunk->rows;
-			a_countdown=a_chunk->count;
-		}
+size_t String::Body::strrpbrk(const char* chars, size_t left, size_t right) const {
+	if(is_empty() || !chars || !strlen(chars))
+		return STRING_NOT_FOUND;
+	CORD_pos_info info={chars, left, right};
+	if(CORD_riter4(body, right, (CORD_iter_fn)CORD_iter_fn_rpos, &info))
+		return info.pos;
+	else
+		return STRING_NOT_FOUND;
+}
+
+
+// can be called only for IS_FUNCTION(CORD) which is used in String::Body::rskipchars
+static int CORD_iter_fn_rskip(char c, CORD_pos_info* info) {
+	if(info->pos < info->left) {
+		info->pos=STRING_NOT_FOUND;
+		return 1;
 	}
-	if(a_break==b_break) { // ended simultaneously
-		partial=0; return 0;
-	} else if(a_break) { // first bytes equal, but a ended before b
-		partial=1; return -1;
+	if(!strchr(info->chars, c))
+		return 1;
+	--(info->pos);
+	return 0;
+}
+
+size_t String::Body::rskipchars(const char* chars, size_t left, size_t right) const {
+	if(is_empty() || !chars || !strlen(chars))
+		return STRING_NOT_FOUND;
+	CORD_pos_info info={chars, left, right};
+	if(CORD_riter4(body, right, (CORD_iter_fn)CORD_iter_fn_rskip, &info))
+		return info.pos;
+	else
+		return STRING_NOT_FOUND;
+}
+
+// String methods
+
+String& String::append_know_length(const char* str, size_t known_length, Language lang) {
+	if(!known_length)
+		return *this;
+
+	// first: langs
+	langs.append(body, lang, known_length);
+	// next: letters themselves
+	body.append_know_length(str, known_length);
+
+	ASSERT_STRING_INVARIANT(*this);
+	return *this;
+}
+String& String::append_help_length(const char* str, size_t helper_length, Language lang) {
+	if(!str)
+		return *this;
+	size_t known_length=helper_length?helper_length:strlen(str);
+	if(!known_length)
+		return *this;
+
+	return append_know_length(str, known_length, lang);
+}
+String::String(int value, char *format) : langs(L_CLEAN){
+	char buf[MAX_NUMBER];
+	body.append_strdup_know_length(buf, snprintf(buf, MAX_NUMBER, format, value));
+}
+String& String::append_strdup(const char* str, size_t helper_length, Language lang) {
+	size_t known_length=helper_length?helper_length:strlen(str);
+	if(!known_length)
+		return *this;
+
+	// first: langs
+	langs.append(body, lang, known_length);
+	// next: letters themselves
+	body.append_strdup_know_length(str, known_length);
+
+	ASSERT_STRING_INVARIANT(*this);
+	return *this;
+}
+
+struct CORD_length_info {
+	size_t len;
+	size_t skip;
+};
+
+int CORD_batched_len(const char* s, CORD_length_info* info){
+	info->len += lengthUTF8( (const XMLByte *)s, (const XMLByte *)s+strlen(s));	return 0;
+}
+
+// can be called only for IS_FUNCTION(CORD) which are used in large String::Body::mid
+int CORD_batched_len(const char c, CORD_length_info* info){
+	if (info->skip==0){
+		info->len++;
+		info->skip = lengthUTF8Char(c)-1;
 	} else {
-		partial=2; return +1;
+		info->skip--;
 	}
+	return 0;
 }
 
-#ifndef NO_STRING_ORIGIN
-const Origin& String::origin() const { 
-	if(!fused_rows)
-		THROW(0, 0, 
-			0,
-			"String::origin() of empty string called");
-	
-	// determining origin by last appended piece
-	// because first one frequently constant. 
-	// ex: ^load[/file] "document_root" + "/file"
-	return append_here[-1].item.origin; 
+size_t String::length(Charset& charset) const {
+	if(charset.isUTF8()){
+		CORD_length_info info = {0, 0};
+		body.for_each<CORD_length_info *>(CORD_batched_len, CORD_batched_len, &info);
+		return info.len;
+	} else
+		return body.length();
 }
-#endif
 
-String& String::mid(size_t start, size_t finish) const {
-	start=max(0, start);
-	finish=min(size(), finish);
-	if(start==finish)
-		return *empty_string;
-
-	String& result=*NEW String(pool());
-
-	size_t pos=0;
-	const Chunk *chunk=&head; 
-	do {
-		const Chunk::Row *row=chunk->rows;
-		for(size_t i=0; i<chunk->count; pos+=row->item.size, i++, row++) {
-			if(row==append_here)
-				goto break2;
-
-			size_t item_finish=pos+row->item.size;
-			if(item_finish > start) { // started now or already?
-				bool started=result.size()==0; // started now?
-				bool finished=finish <= item_finish; // finished now?
-				size_t offset=started?start-pos:0;
-				size_t size=finished?finish-pos:row->item.size;
-				result.APPEND(
-					row->item.ptr+offset, size-offset, 
-					row->item.lang,
-					row->item.origin.file, row->item.origin.line);
-				if(finished)
-					goto break2;
-			}
-		}
-		chunk=row->link;
-	} while(chunk);
-break2:
-//	SAPI::log(pool(), "piece of '%s' from %d to %d is '%s'",
-		//cstr(), start, finish, result.cstr());
+/// @todo check in doc: whether it documents NOW bad situation "abc".mid(-1, 3) =were?="ab"
+String& String::mid(size_t substr_begin, size_t substr_end) const {
+	String& result=*new String;
+
+	size_t self_length=length();
+	substr_begin=min(substr_begin, self_length);
+	substr_end=min(max(substr_end, substr_begin), self_length);
+	size_t substr_length=substr_end-substr_begin;
+	if(!substr_length)
+		return result;
+
+	// first: their langs
+	result.langs.append(result.body, langs, substr_begin, substr_length);
+	// next: letters themselves
+	result.body=body.mid(substr_begin, substr_length);
+
+	ASSERT_STRING_INVARIANT(result);
 	return result;
 }
 
-int String::pos(const String& substr, 
-				size_t result, Untaint_lang lang) const {
-	for(; result<size(); result++) {
-		int partial; cmp(partial, substr, result, lang);
-		if(
-			partial==0 || // full match
-			partial==2) // 'substr' starts 'this'+'result'
+// from, to and helper_length in characters, not in bytes (it's important for utf-8)
+String& String::mid(Charset& charset, size_t from, size_t to, size_t helper_length) const {
+	String& result=*new String;
+
+	size_t self_length=(helper_length)?helper_length:length(charset);
+
+	if(!self_length)
+		return result;
+
+	from=min(min(to, from), self_length);
+	to=min(max(to, from), self_length);
+
+	size_t substr_length=to-from;
+
+	if(!substr_length)
+		return result;
+
+	if(charset.isUTF8()){
+		const XMLByte* src_begin=(const XMLByte*)cstr();
+		const XMLByte* src_end=src_begin+body.length();
+
+		// convert 'from' and 'substr_length' from 'characters' to 'bytes'
+		from=getUTF8BytePos(src_begin, src_end, from);
+		substr_length=getUTF8BytePos(src_begin+from, src_end, substr_length);
+		if(!substr_length)
 			return result;
 	}
-	
-	return -1;
+
+	// first: their langs
+	result.langs.append(result.body, langs, from, substr_length);
+	// next: letters themselves
+	result.body=body.mid(from, substr_length);
+
+	ASSERT_STRING_INVARIANT(result);
+	return result;
 }
 
-int String::pos(const char *substr, size_t substr_size, 
-				size_t result, Untaint_lang lang) const {
-	for(; result<size(); result++) {
-		int partial; cmp(partial, substr, substr_size, result, lang);
-		if(
-			partial==0 || // full match
-			partial==2) // 'substr' starts 'this'+'result'
-			return result;
+size_t String::pos(const String::Body substr, size_t this_offset, Language lang) const {
+	size_t substr_length=substr.length();
+	while(true) {
+		size_t substr_begin=body.pos(substr, this_offset);
+		
+		if(substr_begin==CORD_NOT_FOUND)
+			return STRING_NOT_FOUND;
+
+		if(langs.check_lang(lang, substr_begin, substr_length))
+			return substr_begin;
+
+		this_offset=substr_begin+substr_length;
 	}
-	
-	return -1;
 }
 
-void String::split(Array& result, 
-				   size_t* pos_after_ref, 
-				   const char *delim, size_t delim_size, 
-				   Untaint_lang lang, int limit) const {
-	if(delim_size) {
-		size_t pos_after=pos_after_ref?*pos_after_ref:0;
-		int pos_before;
+size_t String::pos(const String& substr, 
+				size_t this_offset, Language lang) const {
+	return pos(substr.body, this_offset, lang);
+}
+
+size_t String::pos(Charset& charset, const String& substr, 
+				size_t this_offset, Language lang) const {
+
+	if(charset.isUTF8()){
+		const XMLByte* srcPtr=(const XMLByte*)cstr();
+		const XMLByte* srcEnd=srcPtr+body.length();
+
+		// convert 'this_offset' from 'characters' to 'bytes'
+		this_offset=getUTF8BytePos(srcPtr, srcEnd, this_offset);
+
+		size_t result=pos(substr.body, this_offset, lang);
+		return (result==CORD_NOT_FOUND)
+			? STRING_NOT_FOUND
+			: getUTF8CharPos(srcPtr, srcEnd, result); // convert 'result' from 'bytes' to 'characters'
+	} else {
+		size_t result=pos(substr.body, this_offset, lang);
+		return (result==CORD_NOT_FOUND)
+			? STRING_NOT_FOUND
+			: result;
+	}
+}
+
+void String::split(ArrayString& result, 
+		   size_t& pos_after, 
+		   const char* delim, 
+		   Language lang, int limit) const {
+	if(is_empty())
+		return;
+	size_t self_length=length();
+	if(size_t delim_length=strlen(delim)) {
+		size_t pos_before;
 		// while we have 'delim'...
-		for(; (pos_before=pos(delim, delim_size, pos_after, lang))>=0 && limit; limit--) {
+		for(; (pos_before=pos(delim, pos_after, lang))!=STRING_NOT_FOUND && limit; limit--) {
 			result+=&mid(pos_after, pos_before);
-			pos_after=pos_before+delim_size;
+			pos_after=pos_before+delim_length;
 		}
 		// last piece
-		if(pos_after<size() && limit) {
-			result+=&mid(pos_after, size());
-			pos_after=size();
+		if(pos_after<self_length && limit) {
+			result+=&mid(pos_after, self_length);
+			pos_after=self_length;
 		}
-		if(pos_after_ref)
-			*pos_after_ref=pos_after;
 	} else { // empty delim
 		result+=this;
-		if(pos_after_ref)
-			*pos_after_ref+=size();
+		pos_after+=self_length;
 	}
 }
 
-void String::split(Array& result, 
-				   size_t* pos_after_ref, 
-				   const String& delim, Untaint_lang lang, 
-				   int limit) const {
-	if(delim.size()) {
-		size_t pos_after=pos_after_ref?*pos_after_ref:0;
-		int pos_before;
+void String::split(ArrayString& result, 
+		   size_t& pos_after, 
+		   const String& delim, Language lang, 
+		   int limit) const {
+	if(is_empty())
+		return;
+	if(!delim.is_empty()) {
+		size_t pos_before;
 		// while we have 'delim'...
-		for(; (pos_before=pos(delim, pos_after, lang))>=0 && limit; limit--) {
+		for(; (pos_before=pos(delim, pos_after, lang))!=STRING_NOT_FOUND && limit; limit--) {
 			result+=&mid(pos_after, pos_before);
-			pos_after=pos_before+delim.size();
+			pos_after=pos_before+delim.length();
 		}
 		// last piece
-		if(pos_after<size() && limit) {
-			result+=&mid(pos_after, size());
-			pos_after=size();
+		if(pos_after<length() && limit) {
+			result+=&mid(pos_after, length());
+			pos_after=length();
 		}
-		if(pos_after_ref)
-			*pos_after_ref=pos_after;
 	} else { // empty delim
 		result+=this;
-		if(pos_after_ref)
-			*pos_after_ref+=size();
+		pos_after+=length();
 	}
 }
 
-static void regex_options(char *options, int *result){
-    struct Regex_option {
-		char key;
-		int clear, set;
-		int *result;
-    } regex_option[]={
-		{'i', 0, PCRE_CASELESS, result}, // a=A
-		{'s', 0, PCRE_DOTALL, result}, // \n\n$
-		{'x', 0, PCRE_EXTENDED, result}, // whitespace in regex ignored
-		{'m', PCRE_DOTALL, PCRE_MULTILINE, result}, // ^aaa\n$^bbb\n$
-		{'g', 0, true, result+1}, // many rows
-		{0},
-    };
-	result[0]=PCRE_EXTRA | PCRE_DOTALL;
-	result[1]=0;
-
-    if(options) 
-		for(Regex_option *o=regex_option; o->key; o++) 
-			if(
-				strchr(options, o->key) || 
-				strchr(options, toupper(o->key))) {
-				*(o->result)&=~o->clear;
-				*(o->result)|=o->set;
-			}
-}
+Table* String::match(VRegex* vregex,
+			Row_action row_action, void *info,
+			int& matches_count) const { 
 
-/**
-	returns true if fills table.
-	table format is defined and fixed[can be used by others]: 
-	@verbatim
-		pre-match/match/post-match/1/2/3/...
-	@endverbatim
-*/
-bool String::match(const unsigned char *pcre_tables,
-				   const String *aorigin,
-				   const String& regexp, 
-				   const String *options,
-				   Table **table,
-				   Row_action row_action, void *info) const { 
-
-	if(!regexp.size())
-		THROW(0, 0,
-			aorigin,
-			"regexp is empty");
-	const char *pattern=regexp.cstr(UL_AS_IS);
-	const char *errptr;
-	int erroffset;
-    int option_bits[2];  regex_options(options?options->cstr():0, option_bits);
-	pcre *code=pcre_compile(pattern, option_bits[0], 
-		&errptr, &erroffset,
-		pcre_tables);
-
-	if(!code)
-		THROW(0, 0,
-			&regexp.mid(erroffset, regexp.size()),
-			"regular expression syntax error - %s", errptr);
-	
-	int info_substrings=pcre_info(code, 0, 0);
-	if(info_substrings<0) {
-		(*pcre_free)(code);
-		THROW(0, 0,
-			aorigin,
-			"pcre_info error (%d)", 
-				info_substrings);
-	}
-
-	int startoffset=0;
-	const char *subject=cstr(UL_AS_IS);
-	int length=strlen(subject);
-	int ovecsize;
-	int *ovector=(int *)malloc(sizeof(int)*
-		(ovecsize=(1/*match*/+info_substrings)*3));
-
-	{ // create table
-		Array& columns=*NEW Array(pool());
-		columns+=string_pre_match_name;
-		columns+=string_match_name;
-		columns+=string_post_match_name;
-		for(int i=1; i<=info_substrings; i++) {
-			char *column=(char *)malloc(MAX_NUMBER);
-			snprintf(column, MAX_NUMBER, "%d", i);
-			columns+=NEW String(pool(), column); // .i column name
-		}
-		*table=NEW Table(pool(), aorigin, &columns);
-	}
+	// vregex->info(); // I have no idea what does it for?
+
+	bool need_pre_post_match=vregex->is_pre_post_match_needed();
+	bool global=vregex->is_global_search();
 
-	int exec_option_bits=0;
+	const char* subject=cstr();
+	size_t subject_length=length();
+	const int ovector_size=(1/*match*/+MAX_MATCH_GROUPS)*3;
+	int ovector[ovector_size];
+
+	Table::Action_options table_options;
+	Table& table=*new Table(string_match_table_template, table_options);
+
+	int prestart=0;
+	int poststart=0;
+	int postfinish=length();
 	while(true) {
-		int exec_substrings=pcre_exec(code, 0,
-			subject, length, startoffset,
-			exec_option_bits, ovector, ovecsize);
-		
-		if(exec_substrings==PCRE_ERROR_NOMATCH) {
-			(*pcre_free)(code);
-			(*row_action)(**table, 0/*last time, no row*/, 0, 0, info);
-			return option_bits[1]!=0; // global=true+table, not global=false
-		}
-
-		if(exec_substrings<0) {
-			(*pcre_free)(code);
-			THROW(0, 0,
-				aorigin,
-				"regular expression execute error (%d)", 
-					exec_substrings);
-		}
-
-		Array& row=*NEW Array(pool());
-		row+=&mid(0, ovector[0]); // .pre-match column value
-		row+=&mid(ovector[0], ovector[1]); // .match
-		row+=&mid(ovector[1], size()); // .post-match
+		int exec_result=vregex->exec(subject, subject_length, ovector, ovector_size, prestart);
+
+		if(exec_result<0) // only PCRE_ERROR_NOMATCH might be here, other negative results cause an exception
+			break;
+
+		int prefinish=ovector[0];
+		poststart=ovector[1];
+
+		if (prestart==poststart && subject[poststart]=='\n'){
+			prestart++;
+			continue;
+		}
+
+		ArrayString* row=new ArrayString(3);
+		if(need_pre_post_match) {
+			*row+=&mid(0, prefinish); // .prematch column value
+			*row+=&mid(prefinish, poststart); // .match
+			*row+=&mid(poststart, postfinish); // .postmatch
+		} else {
+			*row+=&Empty; // .prematch column value
+			*row+=&Empty; // .match
+			*row+=&Empty; // .postmatch
+		}
 		
-		for(int i=1; i<exec_substrings; i++) {
+		for(int i=1; i<exec_result; i++) {
 			// -1:-1 case handled peacefully by mid() itself
-			row+=&mid(ovector[i*2+0], ovector[i*2+1]); // .i column value
+			*row+=(ovector[i*2+0]>=0 && ovector[i*2+1]>0)?&mid(ovector[i*2+0], ovector[i*2+1]):new String; // .i column value
 		}
 		
-		(*row_action)(**table, &row, startoffset, ovector[0], info);
+		matches_count++;
+		row_action(table, row, prestart, prefinish, poststart, postfinish, info);
 
-		if(!option_bits[1] || !(startoffset=ovector[1])) { // not global | going to hang
-			(*pcre_free)(code);
-			(*row_action)(**table, 0/*last time, no row*/, 0, 0, info);
-			return true;
+		if(!global || prestart==poststart) // last step
+			break;
+
+		prestart=poststart;
+	}
+
+	row_action(table, 0/*last time, no raw*/, 0, 0, poststart, postfinish, info);
+	return vregex->is_just_count() ? 0 : &table;
+}
+
+String& String::change_case(Charset& source_charset, Change_case_kind kind) const {
+	String& result=*new String();
+	if(is_empty())
+		return result;
+
+	char* new_cstr=cstrm();
+
+	if(source_charset.isUTF8()) {
+		size_t new_cstr_len=length();
+		switch(kind) {
+		case CC_UPPER:
+			change_case_UTF8((const XMLByte*)new_cstr, new_cstr_len, (XMLByte*)new_cstr, new_cstr_len, UTF8CaseToUpper);
+			break;
+		case CC_LOWER:
+			change_case_UTF8((const XMLByte*)new_cstr, new_cstr_len, (XMLByte*)new_cstr, new_cstr_len, UTF8CaseToLower);
+			break;
+		default:
+			assert(!"unknown change case kind");
+			break; // never
+		}	
+		
+	} else {
+		const unsigned char *tables=source_charset.pcre_tables;
+
+		const unsigned char *a;
+		const unsigned char *b;
+		switch(kind) {
+		case CC_UPPER:
+			a=tables+lcc_offset;
+			b=tables+fcc_offset;
+			break;
+		case CC_LOWER:
+			a=tables+lcc_offset;
+			b=0;
+			break;
+		default:
+			assert(!"unknown change case kind");
+			a=b=0; // calm, compiler
+			break; // never
+		}	
+
+		char *dest=new_cstr;
+		unsigned char index;
+		for(const char* current=new_cstr; (index=(unsigned char)*current); current++) {
+			unsigned char c=a[index];
+			if(b)
+				c=b[c];
+
+			*dest++=(char)c;
+		}
+	}
+	result.langs=langs;
+	result.body=new_cstr;
+
+	return result;
+}
+
+const String& String::escape(Charset& source_charset) const {
+	if(is_empty())
+		return *this;
+
+	return Charset::escape(*this, source_charset);
+}
+
+#define STRING_APPEND(result, from_cstr, langs, langs_offset, length) \
+			result.langs.append(result.body, langs, langs_offset, length); \
+			result.body.append_strdup_know_length(from_cstr, length);
+
+const String& String::replace(const Dictionary& dict) const {
+	if(!dict.count() || is_empty())
+		return *this;
+
+	String& result=*new String();
+	const char* old_cstr=cstr();
+	const char* prematch_begin=old_cstr;
+
+	if(dict.count()==1) {
+		// optimized simple case
+
+		Dictionary::Subst subst=dict.get(0);
+		while(const char* p=strstr(prematch_begin, subst.from)) {
+			// prematch
+			if(size_t prematch_length=p-prematch_begin) {
+				STRING_APPEND(result, prematch_begin, langs, prematch_begin-old_cstr, prematch_length)
+			}
+
+			// match
+			prematch_begin=p+subst.from_length;
+
+			if(const String* b=subst.to) // are there any b?
+				result<<*b;
+		}
+
+	} else {
+
+		const char* current=old_cstr;
+		while(*current) {
+			if(Dictionary::Subst subst=dict.first_that_begins(current)) {
+				// prematch
+				if(size_t prematch_length=current-prematch_begin) {
+					STRING_APPEND(result, prematch_begin, langs, prematch_begin-old_cstr, prematch_length)
+				}
+
+				// match
+				// skip 'a' in 'current'; move prematch_begin
+				current+=subst.from_length; prematch_begin=current;
+
+				if(const String* b=subst.to) // are there any b?
+					result<<*b;
+			} else // simply advance
+				current++; 
 		}
 
-/*
-		if(option_bits[0] & PCRE_MULTILINE)
-			exec_option_bits|=PCRE_NOTBOL; // start of subject+startoffset not BOL
-*/
 	}
+
+	if(prematch_begin==old_cstr) // not modified
+		return *this;
+
+	// postmatch
+	if(size_t postmatch_length=old_cstr+length()-prematch_begin) {
+		STRING_APPEND(result, prematch_begin, langs, prematch_begin-old_cstr, postmatch_length)
+	}
+
+	ASSERT_STRING_INVARIANT(result);
+	return result;
+}
+
+static int serialize_body_char(char c, char** cur) {
+	*((*cur)++)=c;
+	return 0; // 0=continue
+};
+static int serialize_body_piece(const char* s, char** cur) {
+	size_t length=strlen(s);
+	memcpy(*cur, s, length);  *cur+=length;
+	return 0; // 0=continue
+};
+static int serialize_lang_piece(char alang, size_t asize, char** cur) {
+	// lang
+	**cur=alang; (*cur)++;
+	// length [WARNING: not cast, addresses must be %4=0 on sparc]
+	memcpy(*cur, &asize, sizeof(asize));  *cur+=sizeof(asize);
+
+	return 0; // 0=continue
+}
+String::Cm String::serialize(size_t prolog_length) const {
+	size_t fragments_count=langs.count();
+	size_t body_length=body.length();
+	size_t buf_length=
+		prolog_length //1
+		+sizeof(size_t) //2
+		+body_length //3
+		+1 // 4 for zero terminator used in deserialize
+		+sizeof(size_t) //5
+		+fragments_count*(sizeof(char)+sizeof(size_t)); //6
+
+	String::Cm result(new(PointerFreeGC) char[buf_length], buf_length);
+
+	// 1: prolog
+	char *cur=result.str+prolog_length;
+	// 2: chars.count [WARNING: not cast, addresses must be %4=0 on sparc]
+	memcpy(cur, &body_length, sizeof(body_length));  cur+=sizeof(body_length);
+	// 3: letters
+	body.for_each(serialize_body_char, serialize_body_piece, &cur);
+	// 4: zero terminator
+	*cur++=0;
+	// 5: langs.count [WARNING: not cast, addresses must be %4=0 on sparc]
+	memcpy(cur, &fragments_count, sizeof(fragments_count));  cur+=sizeof(fragments_count);
+	// 6: lang info
+	langs.for_each(body, serialize_lang_piece, &cur);
+
+	return result;
+}
+bool String::deserialize(size_t prolog_size, void *buf, size_t buf_size) {
+	size_t in_buf=buf_size;
+	if(in_buf<=prolog_size)
+		return false;
+	in_buf-=prolog_size;
+
+	// 1: prolog
+	const char* cur=(const char* )buf+prolog_size;
+
+	// 2: chars.count
+	size_t body_length;
+	if(in_buf<sizeof(body_length)) // body.length don't fit?
+		return false;
+	// [WARNING: not cast, addresses must be %4=0 on sparc]
+	memcpy(&body_length, cur, sizeof(body_length));  cur+=sizeof(body_length);
+	in_buf-=sizeof(body_length);
+
+	if(in_buf<body_length+1) // letters+terminator don't fit?
+		return false;
+	// 4: zero terminator
+	if(cur[body_length] != 0) // in place?
+		return false;
+	// 3: letters
+	body=String::Body(*cur?cur:0);
+#ifdef STRING_LENGTH_CACHING
+	body.set_length(body_length);
+#endif
+	cur+=body_length+1;
+	in_buf-=body_length+1;
+
+	// 5: langs.count
+	size_t fragments_count;
+	if(in_buf<sizeof(fragments_count)) // langs.count don't fit?
+		return false;
+	// [WARNING: not cast, addresses must be %4=0 on sparc]
+	memcpy(&fragments_count, cur, sizeof(fragments_count));  cur+=sizeof(fragments_count);
+	in_buf-=sizeof(fragments_count);
+	
+	if(fragments_count) {
+		// 6: lang info
+		size_t total_length=0;
+		for(size_t f=0; f<fragments_count; f++) {
+			char lang;
+			size_t fragment_length;
+			size_t piece_length=sizeof(lang)+sizeof(fragment_length);
+			if(in_buf<piece_length) // lang+length
+				return false;
+
+			// lang
+			lang=*cur++;
+			// length [WARNING: not cast, addresses must be %4=0 on sparc]
+			memcpy(&fragment_length, cur, sizeof(fragment_length));  cur+=sizeof(fragment_length);
+
+			size_t combined_length=total_length+fragment_length;
+			if(combined_length>body_length)
+				return false; // file curruption
+			// uchar needed to prevent propagating 0x80 bit to upper bytes
+			langs.append(total_length, (String::Language)(uchar)lang, fragment_length);
+			total_length=combined_length;
+			in_buf-=piece_length;
+		}
+
+		if(total_length!=body_length) // length(all language fragments) vs length(letters)
+			return false;
+	}
+	if(in_buf!=0) // some strange extra bytes
+		return false;
+
+	ASSERT_STRING_INVARIANT(*this);
+	return true;
+}
+
+const char* String::Body::v() const {
+	return CORD_to_const_char_star(body, length());
+}
+void String::Body::dump() const {
+	CORD_dump(body);
+}
+
+const char* String::Languages::v() const {
+	if(opt.is_not_just_lang)
+		return CORD_to_const_char_star(langs, 0);
+	else
+		return (const char*)&langs;
+}
+void String::Languages::dump() const {
+	if(opt.is_not_just_lang)
+		CORD_dump(langs);
+	else
+		puts((const char*)&langs);
+}
+const char* String::v() const {
+	const uint LIMIT_VIEW=20;
+	char* buf=(char*)malloc(MAX_STRING);
+	const char*body_view=body.v();
+	const char*langs_view=langs.v();
+	snprintf(buf, MAX_STRING, 
+		"%d:%.*s%s}   "
+		"{%d:%s",
+		langs.count(), LIMIT_VIEW, langs_view, strlen(langs_view)>LIMIT_VIEW?"...":"",
+		strlen(body_view), body_view
+	);
+
+	return buf;
+}
+
+void String::dump() const {
+	body.dump();
+	langs.dump();
+}
+
+const String& String::trim(String::Trim_kind kind, const char* chars, Charset* source_charset) const {
+	if(is_empty())
+		return *this;
+
+	size_t substr_begin, substr_length;
+	Body new_body=body.trim(kind, chars, &substr_begin, &substr_length, source_charset);
+	if(new_body==body) // we received unchanged pointer, do likewise
+		return *this;
+	// new_body differs from body, adjust langs along
+
+	String& result=*new String;
+	if(!new_body) // body.trim produced empty result
+		return result;
+	// body.trim produced nonempty result
+
+	// first: their langs
+	result.langs.append(result.body, langs, substr_begin, substr_length);
+	// next: letters themselves
+	result.body=new_body;
+
+	ASSERT_STRING_INVARIANT(result);
+	return result;
 }