public static void TestWhiteSpaceRemoval()
{
string formula = "ab cd";
AssertSameValue(SolverTools.RemoveWhiteSpace(formula), "abcd");
formula = "'ab cd'";
AssertSameValue(SolverTools.RemoveWhiteSpace(formula), "'ab cd'");
formula = " 'ab cd' ";
AssertSameValue(SolverTools.RemoveWhiteSpace(formula), "'ab cd'");
formula = " 'ab\\' cd ' ";
AssertSameValue(SolverTools.RemoveWhiteSpace(formula), "'ab\\' cd '");
}
public Expression SymbolicateExpression(string formula, string[] localVariables = null)
{
Expression newExpression = new Expression();
if (localVariables != null)
{
foreach (var localVariableName in localVariables)
{
if (localVariableName[0] == '$')
{
newExpression.SetVariable(localVariableName.Substring(1, localVariableName.Length - 1).Trim(), "");
}
else
{
newExpression.SetVariable(localVariableName.Trim(), 0.0);
}
}
}
formula = SolverTools.RemoveWhiteSpace(formula);
// Check validity
try
{
ValidityChecker.CheckValidity(formula);
}
catch (System.Exception ex)
{
throw ex;
}
Symbol s = Symbolicate(formula, 0, formula.Length, newExpression);
newExpression.root = s;
return(newExpression);
}
Symbol Symbolicate(string formula, int begin, int end, Expression exp)
{
var symbols = new SymbolList();
int i = begin - 1;
int currentTermBegin = formula[begin] == '+' ? begin + 1 : begin;
int currentDepth = 0;
for (;;)
{
i++;
if (i == end || (currentDepth == 0 && i > begin && (formula[i - 1] != '*' && formula[i - 1] != '/') && (formula[i] == '+' || formula[i] == '-')))
{
symbols.Append(SymbolicateMonome(formula, currentTermBegin, i, exp));
if (i == end)
{
break;
}
else
{
// The sign of the term is included in the next monome only if its minus
currentTermBegin = (formula[i] == '-') ? i : i + 1;
symbols.Append(new Symbol(SymbolType.OperatorAdd));
}
}
else if (formula[i] == '(')
{
currentDepth++;
}
else if (formula[i] == ')')
{
currentDepth--;
}
else if (formula[i] == '^')
{
i = SolverTools.ParseUntilEndOfExponent(formula, i + 1, end) - 1;
}
}
// If at this point we only have one real number left, just return it as a simple value.
if (symbols.Length == 1 && symbols.first.type == SymbolType.RealValue)
{
return(symbols.first);
}
// We don't have that single expression, but:
// Now that we are here, we have symbol list which consists of only addition operators and value types. This is a great place to sum constant values together!
double constantSum = 0;
bool addedConstants = false;
for (int j = 0; j < symbols.Length; j++)
{
Symbol s = symbols.getSymbol(j);
if (s.IsImmutableConstant() && s.IsRealValueType())
{
constantSum += s.value;
addedConstants = true;
if (j == symbols.Length - 1)
{
// Destroy preceding +
symbols.symbols.RemoveAt(j);
break;
}
symbols.symbols.RemoveAt(j);
symbols.symbols.RemoveAt(j);
j--;
}
else
{
// Skip the following + symbol
j++;
}
}
if (addedConstants)
{
if (symbols.Length > 0 && symbols.getSymbol(symbols.Length - 1).IsRealValueType())
{
symbols.Append(new Symbol(SymbolType.OperatorAdd));
}
symbols.Append(new Symbol(constantSum));
}
// Finally, if the symbolicated sum is just a single real number, even varying, return just a simple symbol
if (symbols.Length == 1 && symbols.getSymbol(0).type == SymbolType.RealValue)
{
Symbol s = symbols.getSymbol(0);
return(s);
}
// Optimization: get rid of unnecessary jumps to subexpressions
for (int j = 0; j < symbols.Length; j++)
{
var s = symbols.getSymbol(j);
if (s.type == SymbolType.SubExpression)
{
var subExpression = s.subExpression;
int subExpressionLength = subExpression.Length;
s.CopyValuesFrom(subExpression.first);
for (int k = 1; k < subExpressionLength; k++)
{
symbols.InsertBefore(j + k, subExpression.getSymbol(k));
}
j += subExpressionLength;
}
}
// We have turned the formula into a subexpression symbol
Symbol returnSymbol = new Symbol(symbols);
returnSymbol.Simplify();
return(returnSymbol);
}
Symbol SymbolicateValue(string formula, int begin, int end, Expression exp)
{
if (formula[begin] == '+')
{
begin++;
}
// Check for string value
if (formula[begin] == '\'' && formula[end - 1] == '\'')
{
var svalue = formula.Substring(begin + 1, end - begin - 2).Replace("\\'", "'");
return(new Symbol(svalue));
}
int depth = 0;
for (int k = begin; k < end; k++)
{
if (formula[k] == '(')
{
depth++;
}
else if (formula[k] == ')')
{
depth--;
}
else if (depth == 0 && formula[k] == '^')
{
// Check for small integer powers: they will be done using multiplication instead!
Symbol lhs = Symbolicate(formula, begin, k, exp);
Symbol rhs = Symbolicate(formula, k + 1, end, exp);
var newSubExpression = new SymbolList();
if (end - k - 1 == 1 && lhs.type == SymbolType.RealValue && formula.Substring(k + 1, end - k - 1) == "2")
{
// Second power found
newSubExpression.Append(lhs);
newSubExpression.Append(lhs);
}
else if (end - k - 1 == 1 && lhs.type == SymbolType.RealValue && formula.Substring(k + 1, end - k - 1) == "3")
{
// Second power found
newSubExpression.Append(lhs);
newSubExpression.Append(lhs);
newSubExpression.Append(lhs);
}
else
{
newSubExpression.Append(new Symbol(SymbolType.Pow));
newSubExpression.Append(lhs);
newSubExpression.Append(rhs);
}
Symbol newSymbol = new Symbol(SymbolType.SubExpression);
newSymbol.subExpression = newSubExpression;
return(newSymbol);
}
}
if (formula[begin] == '(' && formula[end - 1] == ')')
{
var s = Symbolicate(formula, begin + 1, end - 1, exp);
s.Simplify();
return(s);
}
double valueAsRealNumber;
if (double.TryParse(formula.Substring(begin, end - begin), out valueAsRealNumber))
{
return(new Symbol(valueAsRealNumber));
}
// Check if the value is transformed by a function
if (formula[end - 1] == ')')
{
int i = begin;
while (i < end - 1)
{
if (formula[i] == '(')
{
break;
}
i++;
}
string funcName = formula.Substring(begin, i - begin);
CustomFunction customFunc;
if (customFuncs.TryGetValue(funcName, out customFunc))
{
int requiredParameterCount = customFunc.paramCount;
int foundParameterCount = SolverTools.CountParameters(formula, begin, end);
if (requiredParameterCount == foundParameterCount)
{
if (requiredParameterCount == 1)
{
SymbolList newSubExpression = new SymbolList();
newSubExpression.Append(new Symbol(customFunc));
newSubExpression.Append(Symbolicate(formula, i + 1, end - 1, exp));
return(new Symbol(newSubExpression));
}
else
{
List <SolverTools.IntPair> parameters = SolverTools.ParseParameters(formula, i, end);
SymbolList newSubExpression = new SymbolList();
newSubExpression.Append(new Symbol(customFunc));
for (int k = 0; k < requiredParameterCount; k++)
{
Symbol p = Symbolicate(formula, parameters[k].first, parameters[k].second, exp);
newSubExpression.Append(p);
}
Symbol newSymbol = new Symbol(SymbolType.SubExpression);
newSymbol.subExpression = newSubExpression;
return(newSymbol);
}
}
else
{
throw new ESInvalidParametersException(customFunc.name + " expects " + requiredParameterCount + " parameters, " + foundParameterCount + " given.");
}
}
else
{
throw new ESInvalidFunctionNameException(funcName);
}
}
var valueName = formula.Substring(begin, end - begin);
// Then a local constant specific to our expression
Variable variable;
if (exp.constants.TryGetValue(valueName, out variable))
{
return(new Symbol(variable));
}
// Non immutable globals
if (globalConstants.TryGetValue(valueName, out variable))
{
return(new Symbol(variable));
}
// Immutable globals
double constDouble;
if (immutableGlobalConstants.TryGetValue(valueName, out constDouble))
{
return(new Symbol(constDouble));
}
// Found an unknown value name. Check policy to see what to do.
Variable v = null;
switch (undefinedVariablePolicy)
{
case UndefinedVariablePolicy.DefineExpressionLocalVariable:
v = new Variable(valueName, 0);
exp.constants.Add(valueName, v);
return(new Symbol(v));
case UndefinedVariablePolicy.DefineGlobalVariable:
v = new Variable(valueName, 0);
globalConstants.Add(valueName, v);
return(new Symbol(v));
default:
throw new ESUnknownExpressionException(valueName);
}
}
