changed Awk::parse() to accept a reference type instead of a pointer type

qse/include/qse/awk/Awk.hpp

@@ -1,5 +1,5 @@
 /*
- * $Id: Awk.hpp 230 2009-07-13 08:51:23Z hyunghwan.chung $
+ * $Id: Awk.hpp 231 2009-07-13 10:03:53Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -58,6 +58,15 @@ public:
 	class Run;
 	friend class Run;
 
+protected:
+	class NoSource;
+
+public:
+	/** 
+	 * The Awk::Source class is an abstract class to encapsulate
+	 * source script I/O. The Awk::parse function requires a concrete
+	 * object instantiated from its child class.
+	 */
 	class Source
 	{
 	public:
@@ -67,6 +76,10 @@ public:
 			WRITE   /**< source code write. */
 		};
 
+		/**
+		 * The Awk::Source::Data class is used to deliver information
+		 * needed for source script I/O. 
+		 */
 		class Data
 		{
 		public:
@@ -116,11 +129,27 @@ public:
 		virtual ssize_t read (Data& io, char_t* buf, size_t len) = 0;
 		virtual ssize_t write (Data& io, char_t* buf, size_t len) = 0;
 
+		/**
+		 * special value to indicate no source
+		 */
+		static NoSource NONE;
+
 	private:
 		Source (const Source&);
 		Source& operator= (const Source&);
 	};
 
+protected:
+	class NoSource: public Source
+	{
+	public:
+		int open (Data& io) { return -1; }
+		int close (Data& io) { return 0; }
+		ssize_t read (Data& io, char_t* buf, size_t len) { return 0; }
+		ssize_t write (Data& io, char_t* buf, size_t len) { return 0; }
+	};
+
+public:
 	/**
 	 * The RIOBase class is a base class to represent runtime I/O context.
 	 * The Console, File, Pipe classes inherit this class to implement
@@ -861,14 +890,14 @@ public:
 	/**
 	 * Parses the source code.
 	 *
-	 * Awk::parse parses the source code read from the input stream and 
+	 * Awk::parse parses the source code read from the input stream @a in
-	 * writes the parse tree to the output stream. A child class should
+	 * and writes the parse tree to the output stream @out. To disable
-	 * override Awk::openSource, Awk::closeSource, Awk::readSource, 
+	 * deparsing, you may set @a out to Awk::Source::NONE. However, it 
-	 * Awk::writeSource to implement the source code stream.
+	 * is not legal to specify Awk::Source::NONE for @a in.
 	 *
-	 * @return a Run object on success, QSE_NULL on failure
+	 * @return a Run object on success, #QSE_NULL on failure
 	 */
-	virtual Awk::Run* parse (Source* in, Source* out);
+	virtual Awk::Run* parse (Source& in, Source& out);
 
 	/**
 	 * Executes the BEGIN block, pattern-action blocks, and the END block.

qse/lib/awk/Awk.cpp

@@ -1,5 +1,5 @@
 /*
- * $Id: Awk.cpp 230 2009-07-13 08:51:23Z hyunghwan.chung $
+ * $Id: Awk.cpp 231 2009-07-13 10:03:53Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -39,6 +39,8 @@ struct rxtn_t
 	Awk::Run* run;
 };
 
+Awk::NoSource Awk::Source::NONE;
+
 //////////////////////////////////////////////////////////////////
 // Awk::RIO
 //////////////////////////////////////////////////////////////////
@@ -1275,14 +1277,20 @@ int Awk::unsetAllWords ()
 	return qse_awk_setword (awk, QSE_NULL, 0, QSE_NULL, 0);
 }
 
-Awk::Run* Awk::parse (Source* in, Source* out)
+Awk::Run* Awk::parse (Source& in, Source& out)
 {
 	QSE_ASSERT (awk != QSE_NULL);
 
+	if (&in == &Source::NONE) 
+	{
+		setError (ERR_INVAL);
+		return QSE_NULL;
+	}
+
 	fini_runctx ();
 
-	sourceReader = in;
+	sourceReader = ∈
-	sourceWriter = out;
+	sourceWriter = (&out == &Source::NONE)? QSE_NULL: &out;
 
 	qse_awk_sio_t sio;
 	sio.in = readSource;

qse/samples/awk/awk05.cpp

@@ -52,7 +52,7 @@ static int run_awk (QSE::StdAwk& awk)
 	QSE::StdAwk::SourceFile out (QSE_T("awk05.out"));
 
 	// parse the script string and deparse it to awk05.out.
-	if (awk.parse (&in, &out) == QSE_NULL) return -1;
+	if (awk.parse (in, out) == QSE_NULL) return -1;
 
 	// execute the BEGIN, pattern-action, END blocks.
 	return awk.loop ();

qse/samples/awk/awk06.cpp

@@ -43,7 +43,7 @@ static int run_awk (QSE::StdAwk& awk)
 	QSE::StdAwk::SourceFile out (QSE_T("awk06.out"));
 
 	// parse the script and deparse it to awk06.out
-	run = awk.parse (&in, &out);
+	run = awk.parse (in, out);
 	if (run == QSE_NULL) return -1;
 
 	QSE::StdAwk::Value arg[2];
@@ -52,16 +52,16 @@ static int run_awk (QSE::StdAwk& awk)
 
 	// ret = add (-20, 51) 
 	QSE::StdAwk::Value ret;
-	if (awk.call (QSE_T("add"), &ret, arg, 2) <= -1) return -1;
+	if (awk.call (QSE_T("add"), &ret, arg, QSE_COUNTOF(arg)) <= -1) return -1;
 
 	// ret = mul (ret, 51);
 	arg[0] = ret;
-	if (awk.call (QSE_T("mul"), &ret, arg, 2) <= -1) return -1;
+	if (awk.call (QSE_T("mul"), &ret, arg, QSE_COUNTOF(arg)) <= -1) return -1;
 
 	// ret = div (ret, 2);
 	arg[0] = ret;
 	if (arg[1].setReal (run, 2) <= -1) return -1;
-	if (awk.call (QSE_T("div"), &ret, arg, 2) <= -1) return -1;
+	if (awk.call (QSE_T("div"), &ret, arg, QSE_COUNTOF(arg)) <= -1) return -1;
 
 	// output the result in various types
 	qse_printf (QSE_T("RESULT: (int) [%lld]\n"), (long long)ret.toInt());

qse/samples/awk/awk07.cpp

@@ -33,7 +33,7 @@ static int run_awk (QSE::StdAwk& awk)
 {
 	QSE::StdAwk::Run* run;
 
-	const qse_char_t* script = QSE_T(
+	QSE::StdAwk::SourceString in (QSE_T(
 		"function pa (x) {\n"
 		"	reset ret;\n"
 		"	for (i in x) { print i, \"=>\", x[i]; ret += x[i]; }\n"
@@ -44,15 +44,13 @@ static int run_awk (QSE::StdAwk& awk)
 		"	for (i in x) { ret[-i] = -x[i]; }\n"
 		"	return ret;\n"
 		"}"
-	);
+	));
 
-	QSE::StdAwk::SourceString in (script);
+	// parse the script and perform no deparsing
-	QSE::StdAwk::SourceFile out (QSE_T("awk07.out"));
+	run = awk.parse (in, QSE::StdAwk::Source::NONE);
-
-	// parse the script and deparse it to awk07.out
-	run = awk.parse (&in, &out);
 	if (run == QSE_NULL) return -1;
 
+	// prepare an indexed parameter 
 	QSE::StdAwk::Value arg[1];
 
 	for (int i = 1; i <= 5; i++)