/**************************************************************************************************
 * parser.h
 *
 * 2008-04-20 12:13
 * 周鑫(zhouxin63766@yahoo.com.cn)
 *
 * 語法分析。
 *************************************************************************************************/

#ifndef PARSER_H
#define PARSER_H

#include <cstdarg>
#include <QStringList>
#include "glossary.h"
#include "shared.h"

typedef double (*FuncPtr)(double);
struct ExprNode
{
	enum TokenType opCode;

	union
	{
		struct
		{
			ExprNode *Left;
			ExprNode *Right;
		}CaseOperator;

		struct
		{
			ExprNode *Child;
			FuncPtr MathFuncPtr;
		}CaseFunc;

		double CaseConst;
		double *CaseParmPtr;
	}Content;
};

// Forward declaration
class QString;

class Parser
{
public:
	Parser();
	~Parser();

	bool build( const QString &fileName );

	QStringList errorList()
	{
		return _errorList;
	}
private:
	void fetchToken();
	void matchToken( enum TokenType AToken );
	void syntaxError( int errorCase );
	void printSyntaxTree( struct ExprNode *root, int indent = 1 );

	void program();
	void statement();
	void originStatement();
	void rotStatement();
	void scaleStatement();
	void forStatement();
	struct ExprNode *expression();
	struct ExprNode *term();
	struct ExprNode *factor();
	struct ExprNode *component();
	struct ExprNode *atom();
	struct ExprNode *makeExprNode( enum TokenType opcode, ... );

	Token token;
	double parameter;		// 參數(shù)T的存儲空間
	double originX, originY;	// 橫、縱平移距離
	double scaleX, scaleY;		//橫、縱比例因子
	double rotAngle;		//旋轉(zhuǎn)角度

	QStringList _errorList;
	Glossary *glossary;
	bool noError;
};
#endif