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- Remove while(true) conditional and simplify evaluation of precedence stack.

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This commit is contained in:
Daniel Belcher 2019-03-14 14:20:06 -07:00
commit 091286e8d6
2 changed files with 49 additions and 40 deletions
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88
src/CalcManager/CEngine/scicomm.cpp
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@ -463,45 +463,12 @@ void CCalcEngine::ProcessCommandWorker(OpCode wParam)
m_HistoryCollector.AddOpndToHistory(m_numberString, m_currentVal); m_HistoryCollector.AddOpndToHistory(m_numberString, m_currentVal);
} }
do { // Evaluate the precedence stack.
ResolveHighestPrecedenceOperation();
if (m_nOpCode) /* Is there a valid operation around? */ while (m_fPrecedence && m_precedenceOpCount > 0)
{ {
/* If this is the first EQU in a string, set m_holdVal=m_currentVal */ m_precedenceOpCount--;
/* Otherwise let m_currentVal=m_holdVal. This keeps m_currentVal constant */ m_nOpCode = m_nPrecOp[m_precedenceOpCount];
/* through all EQUs in a row. */
if (m_bNoPrevEqu)
{
m_holdVal = m_currentVal;
}
else
{
m_currentVal = m_holdVal;
DisplayNum(); // to update the m_numberString
m_HistoryCollector.AddBinOpToHistory(m_nOpCode, false);
m_HistoryCollector.AddOpndToHistory(m_numberString, m_currentVal); // Adding the repeated last op to history
}
// Do the current or last operation.
m_currentVal = DoOperation(m_nOpCode, m_currentVal, m_lastVal);
m_nPrevOpCode = m_nOpCode;
m_lastVal = m_currentVal;
/* Check for errors. If this wasn't done, DisplayNum */
/* would immediately overwrite any error message. */
if (!m_bError)
DisplayNum();
/* No longer the first EQU. */
m_bNoPrevEqu = false;
}
else if (!m_bError)
DisplayNum();
if (m_precedenceOpCount == 0 || !m_fPrecedence)
break;
m_nOpCode = m_nPrecOp[--m_precedenceOpCount];
m_lastVal = m_precedenceVals[m_precedenceOpCount]; m_lastVal = m_precedenceVals[m_precedenceOpCount];
// Precedence Inversion check // Precedence Inversion check
@ -514,7 +481,9 @@ void CCalcEngine::ProcessCommandWorker(OpCode wParam)
m_HistoryCollector.PopLastOpndStart(); m_HistoryCollector.PopLastOpndStart();
m_bNoPrevEqu = true; m_bNoPrevEqu = true;
} while (true);
ResolveHighestPrecedenceOperation();
}
if (!m_bError) if (!m_bError)
{ {
@ -789,6 +758,45 @@ void CCalcEngine::ProcessCommandWorker(OpCode wParam)
} }
// Helper function to resolve one item on the precedence stack.
void CCalcEngine::ResolveHighestPrecedenceOperation()
{
if (m_nOpCode) /* Is there a valid operation around? */
{
/* If this is the first EQU in a string, set m_holdVal=m_currentVal */
/* Otherwise let m_currentVal=m_holdVal. This keeps m_currentVal constant */
/* through all EQUs in a row. */
if (m_bNoPrevEqu)
{
m_holdVal = m_currentVal;
}
else
{
m_currentVal = m_holdVal;
DisplayNum(); // to update the m_numberString
m_HistoryCollector.AddBinOpToHistory(m_nOpCode, false);
m_HistoryCollector.AddOpndToHistory(m_numberString, m_currentVal); // Adding the repeated last op to history
}
// Do the current or last operation.
m_currentVal = DoOperation(m_nOpCode, m_currentVal, m_lastVal);
m_nPrevOpCode = m_nOpCode;
m_lastVal = m_currentVal;
/* Check for errors. If this wasn't done, DisplayNum */
/* would immediately overwrite any error message. */
if (!m_bError)
DisplayNum();
/* No longer the first EQU. */
m_bNoPrevEqu = false;
}
else if (!m_bError)
{
DisplayNum();
}
}
// CheckAndAddLastBinOpToHistory // CheckAndAddLastBinOpToHistory
// //
// This is a very confusing helper routine to add the last entered binary operator to the history. This is expected to // This is a very confusing helper routine to add the last entered binary operator to the history. This is expected to

1
src/CalcManager/Header Files/CalcEngine.h
View file

@ -129,6 +129,7 @@ private:
private: private:
void ProcessCommandWorker(OpCode wParam); void ProcessCommandWorker(OpCode wParam);
void ResolveHighestPrecedenceOperation();
void HandleErrorCommand(OpCode idc); void HandleErrorCommand(OpCode idc);
void HandleMaxDigitsReached(); void HandleMaxDigitsReached();
void DisplayNum(void); void DisplayNum(void);