/*
 * Copyright 1997 Perforce Software.  All rights reserved.
 *
 * This file is part of Perforce - the FAST SCM System.
 *
 * Diff code written by James Strickland, May 1997.
 */
 
/*
 * Diff walkers: produce output according to diff style by walking
 * the diff results.
 *
 * Classes defined:
 *
 *	Diff - compare two files, outputting the differences
 * 	DiffFlags - parse diff's -d<flags>
 *
 *	Diff::Diff - set up for diff output
 *	Diff::DiffWithFlags - produces diff output according to flags
 *	Diff::DiffContext - produces diff -c output to a file
 *	Diff::DiffUnified - produces diff -u output to a file
 *	Diff::DiffNorm - produces normal diff output to a file
 *	Diff::DiffRcs - produces diff -n output to a file
 *	Diff::DiffHTML - produces html markup
 *	Diff::DiffSummary - produces a single summary line
 *
 *	Diff::CloseOutput - finish write and collect error status
 */
 
class DiffAnalyze;
class DiffFlags;
class Error;
class FileSys;
class Sequence;
class StrPtr;
typedef signed int LineNo;
 
class Diff {
 
    public:
 
			Diff();
			~Diff();
 
	void		SetInput( FileSys *fx, FileSys *fy, 
				const DiffFlags &flags, Error *e );
	void		SetOutput( const char *fout, Error *e );
	void		SetOutput( FILE *fout );
	void		CloseOutput( Error *e );
 
	void		DiffWithFlags( const DiffFlags &flags );
 
	void		DiffContext( int c = 0 );
	void		DiffUnified( int c = 0 );
	void		DiffNorm();
	void		DiffRcs();
	void		DiffHTML();
	void		DiffSummary();
 
	void		DiffFast() { fastMaxD = 1; }
 
    private:
 
	void		Walker( const char *flags, Sequence *s, 
				LineNo sx, LineNo sy );
 
	Sequence	*spx;
	Sequence	*spy;
	FILE		*out;
	DiffAnalyze	*diff;
	int		closeOut;
	LineType	lineType;
	const char	*newLines;
	int		fastMaxD;
 
} ;
 
class DiffFlags {
 
    public:
			DiffFlags() { type = Normal; sequence = Line; }
			DiffFlags( const char *flags ) { Init( flags ); }
			DiffFlags( const StrPtr *flags ) { Init( flags ); }
 
	void		Init( const char *flags );
	void		Init( const StrPtr *flags );
 
	enum Type     { Normal, Context, Unified, Rcs, HTML, Summary } type;
	enum Sequence { Line, Word, DashL, DashB, DashW } sequence;
	enum Grid     { Optimal, Guarded } grid;
 
	int		contextCount;
} ;