/* Copyright (c) Microsoft Corporation.
   Licensed under the MIT License. */

/* Copyright (c) Microsoft Corporation.
   Licensed under the MIT License. */

/***************************************************************************
	Author: ShonK
	Project: Kauai
	Reviewed:
	Copyright (c) Microsoft Corporation

	A lexer for command scripts.

***************************************************************************/
#ifndef LEX_H
#define LEX_H

enum
	{
	fctNil = 0,		//invalid character
	fctLow = 1,		//lowercase letter
	fctUpp = 2,		//uppercase letter
	fctOct = 4,		//octal
	fctDec = 8,		//digit
	fctHex = 16,	//hex digit
	fctSpc = 32,	//space character
	fctOp1 = 64,	//first character of a multi-character operator
	fctOp2 = 128,	//last character of a multi-character operator
	fctOpr = 256,	//lone character operator
	fctQuo = 512,	//quote character
	};
#define kgrfctDigit (fctOct|fctDec|fctHex)

enum
	{
	ttNil,
	ttError,		//bad token
	ttLong,			//numeric constant
	ttName,			//identifier
	ttString,		//string constant

	ttAdd,			// +
	ttSub,			// -
	ttMul,			// *
	ttDiv,			// /
	ttMod,			// %
	ttInc,			// ++
	ttDec,			// --
	ttBOr,			// |
	ttBAnd,			// &
	ttBXor,			// ^
	ttBNot,			// ~
	ttShr,			// >>
	ttShl,			// <<
	ttLOr,			// ||
	ttLAnd,			// &&
	ttLXor,			// ^^
	ttEq,			// ==
	ttNe,			// !=
	ttGt,			// >
	ttGe,			// >=
	ttLt,			// <
	ttLe,			// <=
	ttLNot,			// !
	ttAssign,		// =
	ttAAdd,			// +=
	ttASub,			// -=
	ttAMul,			// *=
	ttADiv,			// /=
	ttAMod,			// %=
	ttABOr,			// |=
	ttABAnd,		// &=
	ttABXor,		// ^=
	ttAShr,			// >>=
	ttAShl,			// <<=
	ttArrow,		// ->
	ttDot,			// .
	ttQuery,		// ?
	ttColon,		// :
	ttComma,		// ,
	ttSemi,			// ;
	ttOpenRef,		// [
	ttCloseRef,		// ]
	ttOpenParen,	// (
	ttCloseParen,	// )
	ttOpenBrace,	// {
	ttCloseBrace,	// }
	ttPound,		// #
	ttDollar,		// $
	ttAt,			// @
	ttAccent,		// `
	ttBackSlash,	// backslash character (\)
	ttScope,		// ::

	ttLimBase
	};


struct TOK
	{
	long tt;
	long lw;
	STN stn;
	};
typedef TOK *PTOK;


/***************************************************************************
	Base lexer.
***************************************************************************/
#define kcchLexbBuf 512

typedef class LEXB *PLEXB;
#define LEXB_PAR BASE
#define kclsLEXB 'LEXB'
class LEXB : public LEXB_PAR
	{
	RTCLASS_DEC
	ASSERT
	MARKMEM

protected:
	static ushort _mpchgrfct[];

	PFIL _pfil;		//exactly one of _pfil, _pbsf should be non-nil
	PBSF _pbsf;
	STN _stnFile;
	long _lwLine;	//which line
	long _ichLine;	//which character on the line

	FP _fpCur;
	FP _fpMac;
	long _ichLim;
	long _ichCur;
	achar _rgch[kcchLexbBuf];
	bool _fLineStart: 1;
	bool _fSkipToNextLine: 1;
	bool _fUnionStrings: 1;

	ulong _GrfctCh(achar ch)
		{ return (uchar)ch < 128 ? _mpchgrfct[(byte)ch] : fctNil; }
	bool _FFetchRgch(achar *prgch, long cch = 1);
	void _Advance(long cch = 1)
		{ _ichCur += cch; _ichLine += cch; }
	bool _FSkipWhiteSpace(void);
	virtual void _ReadNumber(long *plw, achar ch, long lwBase, long cchMax);
	virtual void _ReadNumTok(PTOK ptok, achar ch, long lwBase, long cchMax)
		{ _ReadNumber(&ptok->lw, ch, lwBase, cchMax); }
	bool _FReadHex(long *plw);
	bool _FReadControlCh(achar *pch);

public:
	LEXB(PFIL pfil, bool fUnionStrings = fTrue);
	LEXB(PBSF pbsf, PSTN pstnFile, bool fUnionStrings = fTrue);
	~LEXB(void);

	virtual bool FGetTok(PTOK ptok);
	virtual long CbExtra(void);
	virtual void GetExtra(void *pv);

	void GetStnFile(PSTN pstn);
	long LwLine(void)
		{ return _lwLine; }
	long IchLine(void)
		{ return _ichLine; }
	};

#endif //!LEX_H