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Up to [parser3project] / parser3 / src / classes

fixed all remained bugs of unitialized simple-typed field

/** @file
	Parser: @b table parser class.

	Copyright (c) 2001-2003 ArtLebedev Group (http://www.artlebedev.com)
	Author: Alexandr Petrosian <paf@design.ru> (http://paf.design.ru)
*/

static const char* IDENT_TABLE_C="$Date: 2003/02/17 17:05:02 $";

#include "classes.h"
#include "pa_vmethod_frame.h"

#include "pa_common.h"
#include "pa_request.h"
#include "pa_vtable.h"
#include "pa_vint.h"
#include "pa_sql_connection.h"
#include "pa_vbool.h"

// class

class MTable: public Methoded {
public: // VStateless_class
	ValuePtr create_new_value() { return ValuePtr(new VTable()); }

public:
	MTable();

public: // Methoded
	bool used_directly() { return true; }
};

// global variable

MethodedPtr table_class(new MTable);

// defines for globals

#define SQL_LIMIT_NAME "limit"
#define SQL_OFFSET_NAME "offset"
#define SQL_DEFAULT_NAME "default"
#define SQL_DISTINCT_NAME "distinct"

// globals

StringPtr sql_limit_name(new String(SQL_LIMIT_NAME));
StringPtr sql_offset_name(new String(SQL_OFFSET_NAME));
StringPtr sql_default_name(new String(SQL_DEFAULT_NAME));
StringPtr sql_distinct_name(new String(SQL_DISTINCT_NAME));

// methods

static void get_copy_options(Request& r, StringPtr method_name, MethodParams& params, int param_index,
							 const Table& source,
							 int& offset,
							 int& limit) {
	Pool& pool=r.pool();

	offset=0;
	limit=0;
	if(params.count()<=param_index)
		return;

	ValuePtr voptions=params.as_no_junction(param_index, "options must be hash, not code");
	if(!voptions->is_string()) {
		if(HashStringValue* options=voptions->get_hash(method_name)) {
			int valid_options=0;
			if(ValuePtr voffset=options->get(sql_offset_name)) {
				valid_options++;
				if(voffset->is_string()) {
					StringPtr  soffset=voffset->get_string(&pool);
					if(*soffset == "cur")
						offset=source.current();
					else
						throw Exception("parser.runtime",
							soffset,
							"must be 'cur' string or expression");
				} else 
					offset=r.process_to_value(voffset)->as_int();
			}
			if(ValuePtr vlimit=options->get(sql_limit_name)) {
				valid_options++;
				limit=r.process_to_value(vlimit)->as_int();
			}
			if(valid_options!=options->count())
				throw Exception("parser.runtime",
					method_name,
					"called with invalid option");
		} else
			throw Exception("parser.runtime",
				method_name,
				"options must be hash");
	}
	if(!limit) // zero limit = sould be 'nothing to copy', for methods zero means 'all'
		limit=-1; // thus fixing
}

static void _create(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	// clone/copy part?
	if(const Table *source=params[0]->get_table()) {
		int offset, limit;
		get_copy_options(r, method_name, params, 1, *source, 
			offset, limit);
		GET_SELF(r, VTable).set_table(TablePtr(new Table(*source, offset, limit)));
		return;
	}

	// data is last parameter
	Temp_lang temp_lang(r, String::UL_PASS_APPENDED);
	StringPtr  data=
		r.process_to_string(params.as_junction(params.count()-1, "body must be code"));

	size_t pos_after=0;
	// parse columns
	Table::columns_type columns;
	if(params.count()==2) {
		columns=Table::columns_type(0); // nameless
	} else {
		columns=Table::columns_type(new ArrayString);

		ArrayString head;
		data->split(head, &pos_after, "\n", 1, String::UL_AS_IS, 1);
		if(head.count())
			head[0]->split(*columns, 0, "\t", 1, String::UL_AS_IS);
	}

	TablePtr table(new Table(method_name, columns));
	// parse cells

	ArrayString rows;
	data->split(rows, &pos_after, "\n", 1, String::UL_AS_IS);
	Array_iterator<StringPtr> i(rows);
	while(i.has_next()) {
		Table::element_type row(new ArrayString);
		StringPtr  string=i.next();
		// remove comment lines
		if(!string->size())
			continue;

		string->split(*row, 0, "\t", 1, String::UL_AS_IS);
		*table+=row;
	}

	// replace any previous table value
	GET_SELF(r, VTable).set_table(table);
}

static void _load(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	StringPtr  first_param=params.as_string(0, "file name must be string");
	int filename_param_index=0;
	bool nameless=*first_param=="nameless";
	if(nameless)
		filename_param_index++;
	int options_param_index=filename_param_index+1;
	
	// loading text
	char *data=file_read_text(pool, r.charsets.source(),
		r.absolute(params.as_string(filename_param_index, "file name must be string")),
		true,
		options_param_index<params.count()?params.as_no_junction(options_param_index, "additional params must be hash")->get_hash(method_name):0
	);

	// parse columns
	Table::columns_type columns;
#ifndef NO_STRING_ORIGIN
	const String_fragment::Origin& origin=method_name->origin();
	const char* file=origin.file;
	uint line=origin.line;
#endif
	if(nameless) {
		columns=Table::columns_type(0); // nameless
	} else {
		columns=Table::columns_type(new ArrayString);

		while(char *row_chars=getrow(&data)) {
			// remove empty&comment lines
			if(!*row_chars || *row_chars == '#')
				continue;
			do {
				StringPtr name(new String);
				name->APPEND_TAINTED(lsplit(&row_chars, '\t'), 0, file, line++);
				*columns+=name;
			} while(row_chars);

			break;
		}
	}

	// parse cells
	TablePtr table(new Table(method_name, columns));
	char *row_chars;
	while(row_chars=getrow(&data)) {
		// remove empty&comment lines
		if(!*row_chars || *row_chars == '#')
			continue;
		Table::element_type row(new ArrayString);
		while(char *cell_chars=lsplit(&row_chars, '\t')) {
			StringPtr cell(new String);
			cell->APPEND_TAINTED(cell_chars, 0, file, line);
			*row+=cell;
		}
#ifndef NO_STRING_ORIGIN
		line++;
#endif
		*table+=row;
	};

	// replace any previous table value
	GET_SELF(r, VTable).set_table(table);
}

/// @todo "x\nx" "xxx""xx"
static void _save(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	ValuePtr vfile_name=params.as_no_junction(params.count()-1, 
		"file name must not be code");

	Table& table=GET_SELF(r, VTable).table(method_name);

	bool do_append=false;
	String sdata;
	if(params.count()==1) { // named output
		// write out names line
		if(table.columns()) { // named table
			Array_iterator<StringPtr> i(*table.columns());
			while(i.has_next()) {
				sdata.append(*i.next(), String::UL_TABLE);
				if(i.has_next())
					sdata.APPEND_CONST("\t");
			}
		} else { // nameless table
			if(int lsize=table.count()?table[0]->count():0)
				for(int column=0; column<lsize; column++) {
					char *cindex_tab=new(pool) char[MAX_NUMBER];
					snprintf(cindex_tab, MAX_NUMBER, "%d\t", column);
					sdata.APPEND_CONST(cindex_tab);
				}
			else
				sdata.APPEND_CONST("empty nameless table");
		}
		sdata.APPEND_CONST("\n");
	} else { // mode specified
		StringPtr  mode=params.as_string(0, "mode must be string");
		if(*mode=="append")
			do_append=true;
		else if(*mode=="nameless")
			/*ok, already skipped names output*/;
		else
			throw Exception("parser.runtime",
				mode,
				"unknown mode, must be 'append'");

	}
	// data lines
	Array_iterator<ArrayStringPtr> i(table);
	while(i.has_next()) {
		Array_iterator<StringPtr> c(*i.next());
		while(c.has_next()) {
			if(StringPtr s=c.next())
				sdata.append(*s, String::UL_TABLE);
			if(c.has_next())
				sdata.APPEND_CONST("\t");
		}
		sdata.APPEND_CONST("\n");
	}

	// write
	file_write(r.absolute(vfile_name->as_string(&pool)), 
		sdata.cstr(), sdata.size(), true, do_append);
}

static void _count(Request& r, StringPtr method_name, MethodParams& ) {
	int result=GET_SELF(r, VTable).table(method_name).count();
	r.write_no_lang(ValuePtr(new VInt(result)));
}

static void _line(Request& r, StringPtr method_name, MethodParams& ) {
	int result=1+GET_SELF(r, VTable).table(method_name).current();
	r.write_no_lang(ValuePtr(new VInt(result)));
}

static void _offset(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	Table& table=GET_SELF(r, VTable).table(method_name);
	if(params.count()) {
		bool absolute=false;
		if(params.count()>1) {
		    StringPtr  whence=params.as_string(0, "whence must be string");
		    if(*whence=="cur")
				absolute=false;
		    else if(*whence=="set")
				absolute=true;
		    else
				throw Exception("parser.runtime",
					whence,
					"is invalid whence, valid are 'cur' or 'set'");
		}
		
		ValuePtr offset_expr=params.as_junction(params.count()-1, "offset must be expression");
		table.offset(absolute, r.process_to_value(offset_expr)->as_int());
	} else
		r.write_no_lang(ValuePtr(new VInt(table.current())));
}

static void _menu(Request& r, StringPtr method_name, MethodParams& params) {
	ValuePtr body_code=params.as_junction(0, "body must be code");
	
	ValuePtr delim_maybe_code=params.count()>1?params[1]:ValuePtr(0);

	Table& table=GET_SELF(r, VTable).table(method_name);
	bool need_delim=false;
	int saved_current=table.current();
	int size=table.count();
	for(int row=0; row<size; row++) {
		table.set_current(row);

		StringOrValue sv_processed=r.process(body_code);
		StringPtr s_processed=sv_processed.get_string();
		if(delim_maybe_code && s_processed && s_processed->size()) { // delimiter set and we have body
			if(need_delim) // need delim & iteration produced string?
				r.write_pass_lang(r.process(delim_maybe_code));
			need_delim=true;
		}
		r.write_pass_lang(sv_processed);
	}
	table.set_current(saved_current);
}

#ifndef DOXYGEN
struct Row_info {
	Request *r;
	Table *table;
	ValuePtr key_code;
	int key_field;
	Array<int>* value_fields;
	HashStringValue* hash;
	bool distinct;
	int row;
};
#endif
static void table_row_to_hash(Table::element_type row, Row_info *info) {
	Pool& pool=info->r->pool();

	StringPtr key;
	if(info->key_code) {
		info->table->set_current(info->row++); // change context row
		StringOrValue sv_processed=info->r->process(info->key_code);
		key=sv_processed.as_string(&pool);
	} else
		key=info->key_field<row->count()?row->get(info->key_field):StringPtr(0);

	if(!key)
		return; // ignore rows without key [too-short-record_array if-indexed]
		
	VHashPtr vhash(new VHash);
	HashStringValue& hash=vhash->hash();
	for(int i=0; i<info->value_fields->count(); i++) {
		int value_field=info->value_fields->get(i);
		if(value_field<row->count())
			hash.put(
				info->table->columns()->get(value_field), 
				ValuePtr(new VString(row->get(value_field))));
	}

	if(info->hash->put_dont_replace(key, vhash)) // put. existed?
		if(!info->distinct)
			throw Exception("parser.runtime",
				key,
				"duplicate key");
}
static void _hash(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	Table& self_table=GET_SELF(r, VTable).table(method_name);
	VHashPtr result(new VHash);
	if(Table::columns_type columns=self_table.columns())
		if(columns->count()>0) {
			bool distinct=false;
			int param_index=params.count()-1;
			if(param_index>0) {
				if(HashStringValue* options=
					params.as_no_junction(param_index, "param must not be code")->get_hash(method_name)) {
					--param_index;
					int valid_options=0;
					if(ValuePtr vdistinct=options->get(sql_distinct_name)) {
						valid_options++;
						distinct=r.process_to_value(vdistinct)->as_bool();
					}
					if(valid_options!=options->count())
						throw Exception("parser.runtime",
							method_name,
							"called with invalid option");
				}
			}
			if(param_index==2) // bad options param type
				throw Exception("parser.runtime",
					method_name,
					"options must be hash");

			Array<int> value_fields;
			if(param_index>0) {
				ValuePtr value_fields_param=params.as_no_junction(param_index, "value field(s) must not be code");
				if(value_fields_param->is_string()) {
					value_fields+=self_table.column_name2index(
						value_fields_param->as_string(&pool), true);
				} else if(Table* value_fields_table=value_fields_param->get_table()) {
					for(int i=0; i<value_fields_table->count(); i++) {
						StringPtr  value_field_name=
							value_fields_table->get(i)->get(0);
						value_fields+=self_table.column_name2index(value_field_name, true);
					}
				} else
					throw Exception("parser.runtime",
						method_name,
						"value field(s) must be string or self_table"
					);
			} else { // by all columns, including key
				for(int i=0; i<columns->count(); i++)
					value_fields+=i;
			}


			{
				Row_info info;
				info.r=&r;
				info.table=&self_table;
				ValuePtr key_param=params[0];
				info.key_code=key_param->get_junction()?key_param:ValuePtr(0);
				info.key_field=info.key_code?-1
					:self_table.column_name2index(key_param->as_string(&pool), true);
				info.value_fields=&value_fields;
				info.hash=&result->hash();
				info.distinct=distinct;

				int saved_current=self_table.current();
				self_table.for_each(table_row_to_hash, &info);
				self_table.set_current(saved_current);
			}
		}
	r.write_no_lang(result);
}

#ifndef DOXYGEN
struct Table_seq_item {
	Table::element_type row;
	union {
		char *c_str;
		double d;
	} value;
};
#endif
static int sort_cmp_string(const void *a, const void *b) {
	return strcmp(
		static_cast<const Table_seq_item *>(a)->value.c_str, 
		static_cast<const Table_seq_item *>(b)->value.c_str
	);
}
static int sort_cmp_double(const void *a, const void *b) {
	double va=static_cast<const Table_seq_item *>(a)->value.d;
	double vb=static_cast<const Table_seq_item *>(b)->value.d;
	if(va<vb)
		return -1;
	else if(va>vb)
		return +1;
	else 
		return 0;
}
static void _sort(Request& r, StringPtr method_name, MethodParams& params) {
	Pool local_pool;
	ValuePtr key_maker=params.as_junction(0, "key-maker must be code");

	bool reverse=params.count()>1/*..[desc|asc|]*/?
		reverse=*params.as_no_junction(1, "order must not be code")->as_string(&local_pool)=="desc":
		false; // default=asc

	Table& old_table=GET_SELF(r, VTable).table(method_name);
	TablePtr new_table(new Table(method_name, old_table.columns()));

	smart_ptr<Table_seq_item> seq(new Table_seq_item[old_table.count()]);
	int i;

	// calculate key values
	bool key_values_are_strings=true;
	for(i=0; i<old_table.count(); i++) {
		old_table.set_current(i);
		// calculate key value
		seq[i].row=old_table[i];
		ValuePtr value=r.process_to_value(key_maker)->as_expr_result(true/*return string as-is*/);
		if(i==0) // determining key values type by first one
			key_values_are_strings=value->is_string();

		if(key_values_are_strings)
			seq[i].value.c_str=value->as_string(&local_pool)->cstr(local_pool);
		else
			seq[i].value.d=value->as_double();
	}
	// sort keys
	_qsort(seq, old_table.count(), sizeof(Table_seq_item), 
		key_values_are_strings?sort_cmp_string:sort_cmp_double);

	// reorder table as they require in 'seq'
	for(i=0; i<old_table.count(); i++)
		*new_table+=seq[reverse?old_table.count()-1-i:i].row;

	// replace any previous table value
	GET_SELF(r, VTable).set_table(new_table);
}

static bool _locate_expression(Request& r, StringPtr method_name, MethodParams& params) {
	if(params.count()>1)
		throw Exception("parser.runtime", 
			method_name,
			"locate by expression has only one parameter - expression");

	ValuePtr expression_code=params.as_junction(0, "must be expression");

	Table& table=GET_SELF(r, VTable).table(method_name);
	int saved_current=table.current();
	int size=table.count();
	for(int row=0; row<size; row++) {
		table.set_current(row);

		if(r.process_to_value(expression_code)->as_bool())
			return true;
	}
	table.set_current(saved_current);
	return false;
}
static bool _locate_name_value(Request& r, StringPtr method_name, MethodParams& params) {
	if(params.count()>2)
		throw Exception("parser.runtime", 
			method_name,
			"locate by name and value has only two parameters - name and value");

	Table& table=GET_SELF(r, VTable).table(method_name);
	return table.locate(
		params.as_string(0, "column name must be string"),
		params.as_string(1, "value must be string")
	);
}
static void _locate(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	bool result=params[0]->get_junction()?
		_locate_expression(r, method_name, params) :
		_locate_name_value(r, method_name, params);
	r.write_no_lang(ValuePtr(new VBool(result)));
}

static void _flip(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	Table& old_table=GET_SELF(r, VTable).table(method_name);
	TablePtr new_table(new Table(method_name, old_table.columns()));
	if(old_table.count())
		if(int old_cols=old_table[0]->count()) 
			for(int column=0; column<old_cols; column++) {
				Table::element_type new_row(new ArrayString(old_table.count()));
				for(int i=0; i<old_table.count(); i++) {
					Table::element_type old_row=old_table[i];
					*new_row+=column<old_row->count()?old_row->get(column):StringPtr(new String);
				}
				*new_table+=new_row;
			}

	r.write_no_lang(ValuePtr(new VTable(new_table)));
}

static void _append(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();
	// data
	Temp_lang temp_lang(r, String::UL_PASS_APPENDED);
	StringPtr string=r.process_to_string(params.as_junction(0, "body must be code"));

	// parse cells
	ArrayStringPtr row(new ArrayString);
	string->split(*row, 0, "\t", 1, String::UL_AS_IS);

	GET_SELF(r, VTable).table(method_name)+=row;
}

static void _join(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();

	Table* maybe_src=params.as_no_junction(0, "table ref must not be code")->get_table();
	if(!maybe_src)
		throw Exception("parser.runtime", 
			method_name, 
			"source is not a table");

	Table& src=*maybe_src;
	Table& dest=GET_SELF(r, VTable).table(method_name);
	if(&src == &dest)
		throw Exception("parser.runtime", 
			method_name, 
			"source and destination are same table");

	int offset, limit;
	get_copy_options(r, method_name, params, 1, src, 
		offset, limit);

	if(Table::columns_type dest_columns=dest.columns()) { // dest is named
		int saved_src_current=src.current();
		int m=src.count()-offset;
		if(!limit || limit>m)
			limit=m;
		int end=offset+limit;
		for(int src_row=offset; src_row<end; src_row++) {
			src.set_current(src_row);
			Table::element_type dest_row(new ArrayString(src.count()));
			for(int dest_column=0; dest_column<dest_columns->count(); dest_column++) {
				StringPtr src_item=src.item(dest_columns->get(dest_column));
				*dest_row+=src_item?src_item:StringPtr(new String);
			}
			dest+=dest_row;
		}
		src.set_current(saved_src_current);
	} else { // dest is nameless
		for(int src_row=0; src_row<src.count(); src_row++)
			dest+=src[src_row];
	}
}

#ifndef DOXYGEN
class Table_sql_event_handlers: public SQL_Driver_query_event_handlers {
	Pool& pool;
	StringPtr  method_name;
	StringPtr  statement_string; const char* statement_cstr;
	ArrayStringPtr columns;
	ArrayString* row;
public:
	TablePtr table;
public:
	Table_sql_event_handlers(Pool& apool, StringPtr amethod_name,
		StringPtr astatement_string, const char* astatement_cstr) :
		pool(apool), 
		method_name(amethod_name),
		statement_string(astatement_string),
		statement_cstr(astatement_cstr),
		columns(new ArrayString)
	{}

	bool add_column(SQL_Error& error, void *ptr, size_t size) {
		try {
			StringPtr column(new String);
			column->APPEND_TAINTED(
				(const char* )ptr, size, 
				statement_cstr, 0);
			*columns+=column;
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Table_sql_event_handlers::add_column");
			return true;
		}
	}
	bool before_rows(SQL_Error& error) { 
		try {
			table=TablePtr(new Table( method_name, columns));
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Table_sql_event_handlers::before_rows");
			return true;
		}
	}
	bool add_row(SQL_Error& error) {
		try {
			*table+=(ArrayStringPtr(row=new ArrayString));
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Table_sql_event_handlers::add_row");
			return true;
		}
	}
	bool add_row_cell(SQL_Error& error, void *ptr, size_t size) {
		try {
			StringPtr cell(new String);
			if(size)
				cell->APPEND_TAINTED(
					(const char* )ptr, size, 
					statement_cstr, table->count()-1);
			*row+=cell;
			return false;
		} catch(...) {
			error=SQL_Error("exception occured in Table_sql_event_handlers::add_row_cell");
			return true;
		}
	}
};
#endif
static void _sql(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();

	ValuePtr statement=params.as_junction(0, "statement must be code");

	ulong limit=0;
	ulong offset=0;
	if(params.count()>1) {
		ValuePtr voptions=params.as_no_junction(1, "options must be hash, not code");
		if(!voptions->is_string())
			if(HashStringValue* options=voptions->get_hash(method_name)) {
				int valid_options=0;
				if(ValuePtr vlimit=options->get(sql_limit_name)) {
					valid_options++;
					limit=(ulong)r.process_to_value(vlimit)->as_double();
				}
				if(ValuePtr voffset=options->get(sql_offset_name)) {
					valid_options++;
					offset=(ulong)r.process_to_value(voffset)->as_double();
				}
				if(valid_options!=options->count())
					throw Exception("parser.runtime",
						method_name,
						"called with invalid option");
			} else
				throw Exception("parser.runtime",
					method_name,
					"options must be hash");
	}

	Temp_lang temp_lang(r, String::UL_SQL);
	StringPtr  statement_string=r.process_to_string(statement);
	const char* statement_cstr=
		statement_string->cstr(pool, String::UL_UNSPECIFIED, r.connection(method_name));
	Table_sql_event_handlers handlers(pool, method_name,
		statement_string, statement_cstr);
#ifdef RESOURCES_DEBUG
	struct timeval mt[2];
	//measure:before
	gettimeofday(&mt[0],NULL);
#endif	
	r.connection(method_name)->query(
		statement_cstr, offset, limit, 
		handlers,
		statement_string);
	
#ifdef RESOURCES_DEBUG
		//measure:after connect
	gettimeofday(&mt[1],NULL);
	
	double t[2];
	for(int i=0;i<2;i++)
	    t[i]=mt[i].tv_sec+mt[i].tv_usec/1000000.0;
	    
	r.sql_request_time+=t[1]-t[0];
#endif	    			

	TablePtr result=
		handlers.table?handlers.table: // query resulted in table? return it
		TablePtr(new Table(method_name, Table::columns_type(0))); // query returned no table, fake it

	// replace any previous table value
	GET_SELF(r, VTable).set_table(result);
}

static void _columns(Request& r, StringPtr method_name, MethodParams& ) {
	Pool& pool=r.pool();

	Table::columns_type result_columns(new ArrayString);
	*result_columns+=StringPtr(new String("column"));
	TablePtr result_table(new Table(method_name, result_columns));

	Table& source_table=GET_SELF(r, VTable).table(method_name);
	if(Table::columns_type source_columns=source_table.columns()) {
		Array_iterator<StringPtr> i(*source_columns);
		while(i.has_next()) {
			Table::element_type result_row(new ArrayString);
			*result_row+=i.next();
			*result_table+=result_row;
		}
	}

	r.write_no_lang(ValuePtr(new VTable(result_table)));
}

static void _select(Request& r, StringPtr method_name, MethodParams& params) {
	Pool& pool=r.pool();

	ValuePtr vcondition=params.as_junction(0, "condition must be expression");

	Table& source_table=GET_SELF(r, VTable).table(method_name);
	TablePtr result_table(new Table(
		source_table.origin_string(), 
		source_table.columns()
	));

	int saved_current=source_table.current();
	int size=source_table.count();
	for(int row=0; row<size; row++) {
		source_table.set_current(row);

		bool condition=r.process_to_value(vcondition, 
				/*0/*no name* /,*/
				false/*don't intercept string*/)->as_bool();

		if(condition) // ...condition is true=
			*result_table+=source_table[row]; // =green light to go to result
	}
	source_table.set_current(saved_current);

	r.write_no_lang(ValuePtr(new VTable(result_table)));
}

// constructor

MTable::MTable(): Methoded("table") {
	// ^table::create{data}
	// ^table::create[nameless]{data}
	// ^table::create[table]
	add_native_method("create", Method::CT_DYNAMIC, _create, 1, 2);
	// old name for compatibility with <= v 1.141 2002/01/25 11:33:45 paf
	add_native_method("set", Method::CT_DYNAMIC, _create, 1, 2); 

	// ^table::load[file]  
	// ^table::load[nameless;file]
	add_native_method("load", Method::CT_DYNAMIC, _load, 1, 3);

	// ^table.save[file]  
	// ^table.save[nameless;file]
	add_native_method("save", Method::CT_DYNAMIC, _save, 1, 2);

	// ^table.count[]
	add_native_method("count", Method::CT_DYNAMIC, _count, 0, 0);

	// ^table.line[]
	add_native_method("line", Method::CT_DYNAMIC, _line, 0, 0);

	// ^table.offset[]  
	// ^table.offset(offset)
	// ^table.offset[cur|set](offset)
	add_native_method("offset", Method::CT_DYNAMIC, _offset, 0, 2);

	// ^table.menu{code}  
	// ^table.menu{code}[delim]
	add_native_method("menu", Method::CT_DYNAMIC, _menu, 1, 2);

	// ^table:hash[key field name]
	// ^table:hash[key field name][value field name(s) string/table]
	add_native_method("hash", Method::CT_DYNAMIC, _hash, 1, 3);

	// ^table.sort{string-key-maker} ^table.sort{string-key-maker}[desc|asc]
	// ^table.sort(numeric-key-maker) ^table.sort(numeric-key-maker)[desc|asc]
	add_native_method("sort", Method::CT_DYNAMIC, _sort, 1, 2);

	// ^table.locate[field;value]
	add_native_method("locate", Method::CT_DYNAMIC, _locate, 1, 2);

	// ^table.flip[]
	add_native_method("flip", Method::CT_DYNAMIC, _flip, 0, 0);

	// ^table.append{r{tab}e{tab}c{tab}o{tab}r{tab}d}
	add_native_method("append", Method::CT_DYNAMIC, _append, 1, 1);

	// ^table.join[table][$.limit(10) $.offset(1) $.offset[cur] ]
	add_native_method("join", Method::CT_DYNAMIC, _join, 1, 2);


	// ^table:sql[query]
	// ^table:sql[query][$.limit(1) $.offset(2)]
	add_native_method("sql", Method::CT_DYNAMIC, _sql, 1, 2);

	// ^table:columns[]
	add_native_method("columns", Method::CT_DYNAMIC, _columns, 0, 0);

	// ^table.select(expression) = table
	add_native_method("select", Method::CT_DYNAMIC, _select, 1, 1);
}