From f4c20290509d7ed3a8fd5304577e7a4cc0b9d974 Mon Sep 17 00:00:00 2001
From: Mike Buland <eichlan@xagasoft.com>
Date: Tue, 3 Apr 2007 03:49:53 +0000
Subject: Ok, no code is left in src, it's all in src/old.  We'll gradually
 move code back into src as it's fixed and re-org'd.  This includes tests,
 which, I may write a unit test system into libbu++ just to make my life
 easier.

---
 src/old/formula.cpp | 262 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 262 insertions(+)
 create mode 100644 src/old/formula.cpp

(limited to 'src/old/formula.cpp')

diff --git a/src/old/formula.cpp b/src/old/formula.cpp
new file mode 100644
index 0000000..cf63cf3
--- /dev/null
+++ b/src/old/formula.cpp
@@ -0,0 +1,262 @@
+#include "formula.h"
+
+subExceptionDef( ParseException );
+
+Formula::Formula()
+{
+	hVars["pi"] = M_PI;
+	hVars["e"] = M_E;
+
+	hFunc["sin"] = FuncSin();
+}
+
+Formula::~Formula()
+{
+}
+
+double Formula::run( char *sFormula )
+{
+	for(;;)
+	{
+		uint8_t tNum = nextToken( &sFormula );
+		if( tNum == symEOS )
+			break;
+		else if( tNum == symSubtract )
+		{
+			tNum = nextToken( &sFormula );
+			if( tNum != symNumber )
+				throw ParseException("Unary minus must be followed by a number, "
+					"variable, function, or parenthesis.");
+			sValue.top() = -sValue.top();
+		}
+		else if( tNum == symOpenParen )
+		{
+			sOper.push( tNum );
+			continue;
+		}
+
+oppart:	uint8_t tOpr = nextToken( &sFormula );
+		if( tOpr == symEOS )
+		{
+			//printf("EOS ");
+			reduce();
+			return sValue.top();
+			break;
+		}
+		if( !sOper.empty() && getPrec( sOper.top() ) > getPrec( tOpr ) )
+		{
+			reduce();
+		}
+		if( tOpr != symCloseParen )
+		{
+			sOper.push( tOpr );
+		}
+		else
+		{
+			reduce( true );
+			goto oppart;
+		}
+	}
+	return sValue.top();
+}
+
+void Formula::reduce( bool bCloseParen )
+{
+	while( !sOper.empty() )
+	{
+		uint8_t nOpr = sOper.top();
+		if( nOpr == symOpenParen )
+		{
+			//printf("Found ( stopping reduction.\n");
+			if( bCloseParen == true )
+				sOper.pop();
+			return;
+		}
+		sOper.pop();
+
+		double dTop = sValue.top();
+		sValue.pop();
+
+		switch( nOpr )
+		{
+			case symAdd:
+				//printf("%f + %f = %f\n", sValue.top(), dTop, sValue.top()+dTop );
+				sValue.top() += dTop;
+				break;
+
+			case symSubtract:
+				//printf("%f - %f = %f\n", sValue.top(), dTop, sValue.top()-dTop );
+				sValue.top() -= dTop;
+				break;
+
+			case symMultiply:
+				//printf("%f * %f = %f\n", sValue.top(), dTop, sValue.top()*dTop );
+				sValue.top() *= dTop;
+				break;
+
+			case symDivide:
+				//printf("%f / %f = %f\n", sValue.top(), dTop, sValue.top()/dTop );
+				sValue.top() /= dTop;
+				break;
+
+			case symExponent:
+				//printf("%f ^ %f = %f\n", sValue.top(), dTop, pow(sValue.top(),dTop) );
+				sValue.top() = pow( sValue.top(), dTop );
+				break;
+
+			case symModulus:
+				//printf("%f %% %f = %f\n", sValue.top(), dTop, fmod(sValue.top(),dTop) );
+				sValue.top() = fmod( sValue.top(), dTop );
+				break;
+		}
+	}
+
+	if( bCloseParen == true )
+	{
+		throw ParseException("Close-paren found without matching open-paren.");
+	}
+}
+
+uint8_t Formula::getPrec( uint8_t nOper )
+{
+	switch( nOper )
+	{
+		case symNumber:
+		case symVariable:
+		case symOpenParen:
+		case symCloseParen:
+			return 0;
+
+		case symAdd:
+		case symSubtract:
+			return 1;
+
+		case symMultiply:
+		case symDivide:
+		case symModulus:
+			return 2;
+
+		case symExponent:
+			return 3;
+
+		default:
+			return 0;
+	}
+}
+
+uint8_t Formula::nextToken( char **sBuf )
+{
+	for(;;)
+	{
+		char cbuf = **sBuf;
+		++(*sBuf);
+		switch( cbuf )
+		{
+			case '+':
+				return symAdd;
+
+			case '-':
+				return symSubtract;
+
+			case '*':
+				return symMultiply;
+
+			case '/':
+				return symDivide;
+
+			case '^':
+				return symExponent;
+
+			case '%':
+				return symModulus;
+
+			case '(':
+				return symOpenParen;
+
+			case ')':
+				return symCloseParen;
+
+			case ' ':
+			case '\t':
+			case '\n':
+			case '\r':
+				break;
+
+			case '\0':
+				return symEOS;
+
+			default:
+				if( cbuf == '.' || (cbuf >= '0' && cbuf <= '9') )
+				{
+					char num[50]={cbuf};
+					int nPos = 1;
+					bool bDot = false;
+
+					for(;;)
+					{
+						cbuf = **sBuf;
+						if( cbuf == '.' )
+						{
+							if( bDot == false )
+								bDot = true;
+							else
+								throw ParseException(
+									"Numbers cannot have more than one "
+									". in them."
+									);
+						}
+						if( cbuf == '.' || (cbuf >= '0' && cbuf <= '9') )
+						{
+							num[nPos++] = cbuf;
+						}
+						else
+						{
+							num[nPos] = '\0';
+							sValue.push( strtod( num, NULL ) );
+							return symNumber;
+						}
+						++(*sBuf);
+					}
+				}
+				else if( (cbuf >= 'a' && cbuf <= 'z') || 
+						 (cbuf >= 'A' && cbuf <= 'Z') ||
+						 (cbuf == '_') )
+				{
+					char tok[50]={cbuf};
+					int nPos = 1;
+
+					for(;;)
+					{
+						cbuf = **sBuf;
+						if( (cbuf >= 'a' && cbuf <= 'z') || 
+							(cbuf >= 'A' && cbuf <= 'Z') ||
+							(cbuf >= '0' && cbuf <= '9') ||
+							cbuf == '_' || cbuf == '.' || cbuf == ':' )
+						{
+							tok[nPos++] = cbuf;
+						}
+						else
+						{
+							tok[nPos] = '\0';
+							//printf("Checking variable \"%s\"\n", tok );
+							try
+							{
+								sValue.push( hVars[tok] );
+								return symNumber;
+							}
+							catch( HashException &e )
+							{
+								throw ParseException(
+									"No variable named \"%s\" exists.",
+									tok
+									);
+							}
+						}
+						++(*sBuf);
+					}
+				}
+				break;
+		}
+	}
+}
+
-- 
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