changed svn layout

git-svn-id: svn://ultimatepp.org/upp/trunk@281 f0d560ea-af0d-0410-9eb7-867de7ffcac7

reference/CParser/main.cpp

@@ -0,0 +1,85 @@
+#include <Core/Core.h>
+
+using namespace Upp;
+
+VectorMap<String, double> var;
+
+double Exp(CParser& p);
+
+double Term(CParser& p)
+{
+	if(p.Id("abs")) {
+		p.PassChar('(');
+		double x = Exp(p);
+		p.PassChar(')');
+		return fabs(x);
+	}
+	if(p.IsId())
+		return var.Get(p.ReadId(), 0);
+	if(p.Char('(')) {
+		double x = Exp(p);
+		p.PassChar(')');
+		return x;
+	}
+	return p.ReadDouble();
+}
+
+double Mul(CParser& p)
+{
+	double x = Term(p);
+	for(;;)
+		if(p.Char('*'))
+			x = x * Term(p);
+		else
+		if(p.Char('/')) {
+			double y = Term(p);
+			if(y == 0)
+				p.ThrowError("Divide by zero");
+			x = x / y;
+		}
+		else
+			return x;
+}
+
+double Exp(CParser& p)
+{
+	double x = Mul(p);
+	for(;;)
+		if(p.Char('+'))
+			x = x + Mul(p);
+		else
+		if(p.Char('-'))
+			x = x - Mul(p);
+		else
+			return x;
+}
+
+CONSOLE_APP_MAIN
+{
+	for(;;) {
+		Cout() << "Expresion: ";
+		String l = ReadStdIn();
+		if(l.IsEmpty())
+			break;
+		CParser p(l);
+		try {
+			String id;
+			if(p.IsId()) {
+				CParser::Pos pos = p.GetPos();
+				id = p.ReadId();
+				if(p.Char('=')) {
+					double x = Exp(p);
+					Cout() << id << " <- " << x << '\n';
+					var.GetAdd(id) = x;
+					goto done;
+				}
+				p.SetPos(pos);
+			}
+			Cout() << Exp(p) << '\n';
+		done:;
+		}
+		catch(CParser::Error e) {
+			Cout() << "ERROR: " << e << '\n';
+		}
+	}
+}