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table compiled

/** @file
	Parser: table class decl.

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

#ifndef PA_TABLE_H
#define PA_TABLE_H

static const char* IDENT_TABLE_H="$Date: 2003/01/28 12:16:18 $";

#include "pa_types.h"
#include "pa_hash.h"
#include "pa_string.h"

/** 
	VTable backend.

	holds:
	- column names[if any]
	- data rows
	- current row pointer

	uses String for column names and data items

	hence most of tables are "named", no need to uptimize nameless onces.
	rows and strings stored are read-only. once stored they can be removed,
	but not altered. that's handy for quick copying & co. see table:join
*/
class Table: public Array<object_ptr<const Array<ConstStringPtr > > > {
public:
	typedef object_ptr<const Array<ConstStringPtr> > columns_type;

	Table(
		ConstStringPtr aorigin_string,
		columns_type acolumns,
		int initial_rows=3);
	Table(const Table& src, int offset=0, int limit=0);

	/// where this table came from, may be NULL
	ConstStringPtr origin_string() { return forigin_string; }

	/// gets column names
	columns_type columns() { return fcolumns; }

	/// moves @a current pointer
	void set_current(int acurrent) { fcurrent=acurrent; }
	/// @return current pointer
	int current() const { return fcurrent; }
	void offset(bool absolute, int offset);

	/** @return column index from @a column_name. '<0' if no such column
		if no such - 'bark'
	*/
	int column_name2index(ConstStringPtr column, bool bark) const;

	/// @return item from @a column
	ConstStringPtr item(int column) const;

	/// @return item from @a column. '0' if no such column
	ConstStringPtr item(ConstStringPtr column) const {
		int index=column_name2index(column, false);
		return index>=0?item(index):ConstStringPtr(0);
	}

	/// saves to text file
	void save(bool nameless_save, object_ptr<const String> file_spec);

	bool locate(int column, ConstStringPtr value);
	bool locate(object_ptr<const String> column, ConstStringPtr value);

	element_type at(int index) const {
		return get(index);
	}

private:
	
	// where this table came from, may be NULL
	ConstStringPtr forigin_string;

	// current row
	int fcurrent;

	// columns
	columns_type fcolumns;

	// column names are already referenced in fcolumns, no need to doublecheck references here
	// column name->number lookup table
	typedef Hash<const String&, int> name2number_hash_class;
	object_ptr<name2number_hash_class> name2number;

	// we own columns?

	bool valid(int index) const { return index>=0 && index<count(); }

};

typedef object_ptr<Table> TablePtr;

#endif