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.

1 files changed, 262 insertions, 0 deletions

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;
+                }
+        }
+}
+