private static bool MergeModulus(ExpressionBase left, ExpressionBase right, out ExpressionBase result)
{
// if either side is a float, convert both to float
if (left.Type == ExpressionType.FloatConstant || right.Type == ExpressionType.FloatConstant)
{
if (!ConvertToFloat(ref left, ref right, out result))
{
return(false);
}
if (((FloatConstantExpression)right).Value == 0.0)
{
result = new ParseErrorExpression("Division by zero");
return(false);
}
result = new FloatConstantExpression(((FloatConstantExpression)left).Value % ((FloatConstantExpression)right).Value);
return(true);
}
if (left.Type == ExpressionType.IntegerConstant && right.Type == ExpressionType.IntegerConstant)
{
if (((IntegerConstantExpression)right).Value == 0)
{
result = new ParseErrorExpression("Division by zero");
return(false);
}
result = new IntegerConstantExpression(((IntegerConstantExpression)left).Value % ((IntegerConstantExpression)right).Value);
return(true);
}
result = new ParseErrorExpression("Cannot modulus expressions");
return(false);
}
private static bool MergeAddition(ExpressionBase left, ExpressionBase right, out ExpressionBase result)
{
// if either side is a string, combine to a larger string
if (left.Type == ExpressionType.StringConstant || right.Type == ExpressionType.StringConstant)
{
var builder = new StringBuilder();
left.AppendStringLiteral(builder);
right.AppendStringLiteral(builder);
result = new StringConstantExpression(builder.ToString());
return(true);
}
// if either side is a float, convert both to float
if (left.Type == ExpressionType.FloatConstant || right.Type == ExpressionType.FloatConstant)
{
if (!ConvertToFloat(ref left, ref right, out result))
{
return(false);
}
result = new FloatConstantExpression(((FloatConstantExpression)left).Value + ((FloatConstantExpression)right).Value);
return(true);
}
if (left.Type == ExpressionType.IntegerConstant && right.Type == ExpressionType.IntegerConstant)
{
result = new IntegerConstantExpression(((IntegerConstantExpression)left).Value + ((IntegerConstantExpression)right).Value);
return(true);
}
result = new ParseErrorExpression("Cannot add expressions");
return(false);
}
private static bool MergeBitwiseAnd(ExpressionBase left, ExpressionBase right, out ExpressionBase result)
{
if (left.Type == ExpressionType.IntegerConstant && right.Type == ExpressionType.IntegerConstant)
{
result = new IntegerConstantExpression(((IntegerConstantExpression)left).Value & ((IntegerConstantExpression)right).Value);
return(true);
}
result = new ParseErrorExpression("Cannot bitwise and expressions");
return(false);
}
/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope" />.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns>
/// <c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result" /> will likely be a <see cref="ParseErrorExpression" />.
/// </returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
ExpressionBase left;
if (!Left.ReplaceVariables(scope, out left))
{
result = left;
return(false);
}
ExpressionBase right;
if (!Right.ReplaceVariables(scope, out right))
{
result = right;
return(false);
}
var integerLeft = left as IntegerConstantExpression;
var integerRight = right as IntegerConstantExpression;
switch (Operation)
{
case MathematicOperation.Add:
var stringLeft = left as StringConstantExpression;
var stringRight = right as StringConstantExpression;
if (stringLeft != null)
{
if (stringRight != null)
{
result = new StringConstantExpression(stringLeft.Value + stringRight.Value);
return(true);
}
if (integerRight != null)
{
result = new StringConstantExpression(stringLeft.Value + integerRight.Value.ToString());
return(true);
}
}
else if (stringRight != null)
{
if (integerLeft != null)
{
result = new StringConstantExpression(integerLeft.Value.ToString() + stringRight.Value);
return(true);
}
}
// prefer constants on right
if (integerLeft != null && integerRight == null)
{
var temp = left;
left = right;
right = temp;
integerRight = integerLeft;
integerLeft = null;
}
if (integerRight != null)
{
if (integerRight.Value == 0) // anything plus 0 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value + integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Subtract:
if (integerRight != null)
{
if (integerRight.Value == 0) // anything minus 0 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value - integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Multiply:
// prefer constants on right
if (integerLeft != null && integerRight == null)
{
var temp = left;
left = right;
right = temp;
integerRight = integerLeft;
integerLeft = null;
}
if (integerRight != null)
{
if (integerRight.Value == 0) // anything times 0 is 0
{
result = right;
return(true);
}
if (integerRight.Value == 1) // anything times 1 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value * integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Divide:
if (integerRight != null)
{
if (integerRight.Value == 0) // division by 0 is impossible
{
result = new ParseErrorExpression("division by zero", this);
return(false);
}
if (integerRight.Value == 1) // anything divided by 1 is itself
{
result = left;
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value / integerRight.Value);
return(true);
}
}
break;
case MathematicOperation.Modulus:
if (integerRight != null)
{
if (integerRight.Value == 0) // division by 0 is impossible
{
result = new ParseErrorExpression("division by zero", this);
return(false);
}
if (integerRight.Value == 1) // anything modulus 1 is 0
{
result = new IntegerConstantExpression(0);
return(true);
}
if (integerLeft != null)
{
result = new IntegerConstantExpression(integerLeft.Value % integerRight.Value);
return(true);
}
}
break;
}
var mathematic = new MathematicExpression(left, Operation, right);
mathematic.Line = Line;
mathematic.Column = Column;
result = mathematic;
return(true);
}
private static bool MergeIdentity(ExpressionBase left, MathematicOperation operation, ExpressionBase right, out ExpressionBase result)
{
bool isZero = false;
bool isOne = false;
var integerRight = right as IntegerConstantExpression;
if (integerRight != null)
{
isZero = (integerRight.Value == 0);
isOne = (integerRight.Value == 1);
}
else
{
var floatRight = right as FloatConstantExpression;
if (floatRight != null)
{
isZero = floatRight.Value == 0.0f;
isOne = floatRight.Value == 1.0f;
}
}
if (isZero)
{
switch (operation)
{
case MathematicOperation.Add:
case MathematicOperation.Subtract:
// anything plus or minus 0 is itself
result = left;
return(true);
case MathematicOperation.Multiply:
case MathematicOperation.BitwiseAnd:
// anything times 0 is 0
// anything bitwise and 0 is 0
result = right;
return(true);
case MathematicOperation.Divide:
case MathematicOperation.Modulus:
result = new ParseErrorExpression("Division by zero");
return(false);
}
}
else if (isOne)
{
switch (operation)
{
case MathematicOperation.Multiply:
case MathematicOperation.Divide:
// anything multiplied or divided by 1 is itself
result = left;
return(true);
case MathematicOperation.Modulus:
// anything modulus 1 is 0
result = new IntegerConstantExpression(0);
return(true);
}
}
result = null;
return(false);
}
private static ExpressionBase ParseClauseCore(PositionalTokenizer tokenizer)
{
ExpressionBase clause;
switch (tokenizer.NextChar)
{
case '!':
tokenizer.Advance();
clause = ParseClause(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ConditionalExpression(null, ConditionalOperation.Not, clause));
case '(':
if (AnonymousUserFunctionDefinitionExpression.IsAnonymousParameterList(tokenizer))
{
return(AnonymousUserFunctionDefinitionExpression.ParseAnonymous(tokenizer));
}
tokenizer.Advance();
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
if (tokenizer.NextChar != ')')
{
if (tokenizer.NextChar == '\0')
{
return(ParseError(tokenizer, "No closing parenthesis found"));
}
return(ParseError(tokenizer, "Expected closing parenthesis, found: " + tokenizer.NextChar));
}
clause.IsLogicalUnit = true;
tokenizer.Advance();
return(clause);
case '"':
try
{
var stringValue = tokenizer.ReadQuotedString().ToString();
return(new StringConstantExpression(stringValue));
}
catch (InvalidOperationException ex)
{
return(ParseError(tokenizer, ex.Message));
}
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return(ParseNumber(tokenizer, true));
case '-':
var tokenStart = tokenizer.Location;
tokenizer.Advance();
if (tokenizer.NextChar >= '0' && tokenizer.NextChar <= '9')
{
var result = ParseNumber(tokenizer, false);
var tokenEnd = result.Location.End;
switch (result.Type)
{
case ExpressionType.IntegerConstant:
result = new IntegerConstantExpression(-((IntegerConstantExpression)result).Value);
break;
case ExpressionType.FloatConstant:
result = new FloatConstantExpression(-((FloatConstantExpression)result).Value);
break;
default:
return(result);
}
result.Location = new TextRange(tokenStart, tokenEnd);
return(result);
}
return(ParseError(tokenizer, "Minus without value", tokenStart.Line, tokenStart.Column));
case '{':
tokenizer.Advance();
return(DictionaryExpression.Parse(tokenizer));
case '[':
tokenizer.Advance();
return(ParseArray(tokenizer));
default:
var line = tokenizer.Line;
var column = tokenizer.Column;
var identifier = tokenizer.ReadIdentifier();
if (identifier.IsEmpty)
{
var error = ParseError(tokenizer, "Unexpected character: " + tokenizer.NextChar);
tokenizer.Advance();
return(error);
}
SkipWhitespace(tokenizer);
if (identifier == "return")
{
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ReturnExpression(new KeywordExpression(identifier.ToString(), line, column), clause));
}
if (identifier == "function")
{
return(UserFunctionDefinitionExpression.Parse(tokenizer, line, column));
}
if (identifier == "for")
{
return(ForExpression.Parse(tokenizer, line, column));
}
if (identifier == "if")
{
return(IfExpression.Parse(tokenizer, line, column));
}
if (identifier == "true")
{
return(new BooleanConstantExpression(true, line, column));
}
if (identifier == "false")
{
return(new BooleanConstantExpression(false, line, column));
}
if (tokenizer.NextChar == '(')
{
tokenizer.Advance();
var parameters = new List <ExpressionBase>();
ParseParameters(tokenizer, parameters);
var functionCall = new FunctionCallExpression(new FunctionNameExpression(identifier.ToString(), line, column), parameters);
functionCall.Location = new TextRange(line, column, tokenizer.Line, tokenizer.Column - 1);
return(functionCall);
}
if (tokenizer.NextChar == '[')
{
IndexedVariableExpression parent = null;
do
{
tokenizer.Advance();
var index = ExpressionBase.Parse(tokenizer);
if (index.Type == ExpressionType.ParseError)
{
return(index);
}
SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ']')
{
return(ParseError(tokenizer, "Expecting closing bracket after index"));
}
tokenizer.Advance();
SkipWhitespace(tokenizer);
if (parent != null)
{
parent = new IndexedVariableExpression(parent, index);
}
else
{
parent = new IndexedVariableExpression(new VariableExpression(identifier.ToString(), line, column), index);
}
} while (tokenizer.NextChar == '[');
return(parent);
}
return(new VariableExpression(identifier.ToString(), line, column));
}
}
private static ExpressionBase ParseNumber(PositionalTokenizer tokenizer, bool isUnsigned)
{
int line = tokenizer.Line;
int column = tokenizer.Column;
int endLine = line;
int endColumn = column;
uint value;
string number = "";
if (tokenizer.Match("0x"))
{
while (Char.IsDigit(tokenizer.NextChar) || (tokenizer.NextChar >= 'A' && tokenizer.NextChar <= 'F') || (tokenizer.NextChar >= 'a' && tokenizer.NextChar <= 'f'))
{
number += tokenizer.NextChar;
endLine = tokenizer.Line;
endColumn = tokenizer.Column;
tokenizer.Advance();
}
if (!UInt32.TryParse(number, System.Globalization.NumberStyles.HexNumber, System.Globalization.CultureInfo.CurrentCulture, out value))
{
return(new ParseErrorExpression("Number too large"));
}
}
else
{
while (Char.IsDigit(tokenizer.NextChar))
{
number += tokenizer.NextChar;
endLine = tokenizer.Line;
endColumn = tokenizer.Column;
tokenizer.Advance();
}
if (tokenizer.NextChar == '.')
{
number += tokenizer.NextChar;
tokenizer.Advance();
while (Char.IsDigit(tokenizer.NextChar))
{
number += tokenizer.NextChar;
endLine = tokenizer.Line;
endColumn = tokenizer.Column;
tokenizer.Advance();
}
float floatValue;
if (!float.TryParse(number, System.Globalization.NumberStyles.AllowDecimalPoint, System.Globalization.CultureInfo.InvariantCulture, out floatValue))
{
return(new ParseErrorExpression("Number too large"));
}
var floatExpression = new FloatConstantExpression(floatValue);
floatExpression.Location = new TextRange(line, column, endLine, endColumn);
return(floatExpression);
}
if (!UInt32.TryParse(number, out value))
{
return(new ParseErrorExpression("Number too large"));
}
}
if (value > Int32.MaxValue && !isUnsigned)
{
return(new ParseErrorExpression("Number too large"));
}
var integerExpression = new IntegerConstantExpression((int)value);
integerExpression.Location = new TextRange(line, column, endLine, endColumn);
return(integerExpression);
}