internal static void LastIndexOfOpArray(List <Token> tokens, string[] ops, EvalConfiguration config, out int matchIndex, out string match)
{
var pos = -1;
string bestMatch = null;
for (var i = 0; i < ops.Length; i++)
{
var item = ops[i];
int opIndex;
if (config.RightAssociativeOps.Contains(item))
{
opIndex = IndexOfOpInTokens(tokens, item);
}
else
{
opIndex = LastIndexOfOpInTokens(tokens, item);
}
if (opIndex == -1)
{
continue;
}
if (pos == -1 || opIndex > pos)
{
pos = opIndex;
bestMatch = item;
}
}
matchIndex = pos;
match = bestMatch;
}
public EvalConfiguration Clone(bool deep = false)
{
var config = new EvalConfiguration(NumericType);
config.OperatorOrder = OperatorOrder;
config.PrefixOperators = deep ? new HashSet <string>(PrefixOperators) : PrefixOperators;
config.SuffixOperators = deep ? new HashSet <string>(SuffixOperators) : SuffixOperators;
config.RightAssociativeOps = deep ? new HashSet <string>(RightAssociativeOps) : RightAssociativeOps;
config.VarNameChars = deep ? new HashSet <char>(VarNameChars) : VarNameChars;
config.GenericConstants = deep ? new Dictionary <string, object>(GenericConstants) : GenericConstants;
config.GenericFunctions = deep ? new Dictionary <string, EvalFunctionDelegate>(GenericFunctions) : GenericFunctions;
config.Constants = deep ? new Dictionary <string, object>(Constants) : Constants;
config.Functions = deep ? new Dictionary <string, EvalFunctionDelegate>(Functions) : Functions;
config.ConstProvider = ConstProvider;
return(config);
}
internal static object EvaluateFunction(Token token, EvalConfiguration configuration)
{
var fname = token.Value;
var args = new List <object>();
for (var i = 0; i < token.Arguments.Count; i++)
{
if (token.Arguments[i] == null)
{
args.Add(null);
}
else
{
args.Add(EvaluateToken(token.Arguments[i], configuration));
}
}
if (configuration.Functions.ContainsKey(fname))
{
return(configuration.Functions[fname](args.ToArray()));
}
if (configuration.Functions.ContainsKey(fname.ToUpperInvariant()))
{
return(configuration.Functions[fname.ToUpperInvariant()](args.ToArray()));
}
if (configuration.GenericFunctions.ContainsKey(fname))
{
return(configuration.GenericFunctions[fname](args.ToArray()));
}
if (configuration.GenericFunctions.ContainsKey(fname.ToUpperInvariant()))
{
return(configuration.GenericFunctions[fname.ToUpperInvariant()](args.ToArray()));
}
throw new Exception("Function named \"" + fname + "\" was not found");
}
internal static string OpAtPosition(string expression, int start, EvalConfiguration configuration)
{
string op = null;
var allOperators = configuration._AllOperators;
for (int j = 0, jlen = allOperators.Length; j < jlen; j++)
{
var item = allOperators[j];
if (op != null && (op == item || item.Length <= op.Length))
{
continue;
}
if (expression.Substring(start, item.Length) == item)
{
op = item;
}
}
return(op);
}
public static object Execute(string expression, EvalConfiguration configuration)
{
return(Execute(Compile(expression, configuration)));
}
internal static object EvaluateToken(Token token, EvalConfiguration configuration)
{
var value = token.Value;
switch (token.Type)
{
case TokenType.String:
return(value);
case TokenType.Number:
return(configuration.ConvertToNumber(value));
case TokenType.Var:
if (configuration.ConstProvider != null)
{
var val = configuration.ConstProvider(value);
if (val != null)
{
return(val);
}
}
if (configuration.Constants.ContainsKey(value))
{
return(configuration.Constants[value]);
}
if (configuration.Constants.ContainsKey(value.ToUpperInvariant()))
{
return(configuration.Constants[value.ToUpperInvariant()]);
}
if (configuration.GenericConstants.ContainsKey(value))
{
return(configuration.GenericConstants[value]);
}
if (configuration.GenericConstants.ContainsKey(value.ToUpperInvariant()))
{
return(configuration.GenericConstants[value.ToUpperInvariant()]);
}
return(null);
case TokenType.Call:
return(EvaluateFunction(token, configuration));
case TokenType.Op:
switch (token.Value)
{
case "!": // Factorial or Not
if (token.Left != null) // Factorial (i.e. 5!)
{
return(configuration.Factorial(EvaluateToken(token.Right, configuration)));
}
else // Not (i.e. !5)
{
return(configuration.LogicalNot(EvaluateToken(token.Right, configuration)));
}
case "/": // Divide
case "\\":
return(configuration.Divide(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "*": // Multiply
return(configuration.Multiply(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "+": // Add
return(configuration.Add(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "-": // Subtract
return(configuration.Subtract(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "<<": // Shift left
return(configuration.BitShiftLeft(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case ">>": // Shift right
return(configuration.BitShiftRight(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "<": // Less than
return(configuration.LessThan(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "<=": // Less than or equals to
return(configuration.LessThanOrEqualsTo(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case ">": // Greater than
return(configuration.GreaterThan(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case ">=": // Greater than or equals to
return(configuration.GreaterThanOrEqualsTo(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "==": // Equals to
case "=":
return(configuration.EqualsTo(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "!=": // Not equals to
case "<>":
return(configuration.NotEqualsTo(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "**": // Power
return(configuration.Pow(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "%": // Mod
return(configuration.Mod(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "&": // Bitwise AND
return(configuration.BitAnd(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "^": // Bitwise XOR
return(configuration.BitXor(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "|": // Bitwise OR
return(configuration.BitOr(EvaluateToken(token.Left, configuration), EvaluateToken(token.Right, configuration)));
case "&&": // Logical AND
{
var res = EvaluateToken(token.Left, configuration);
if (configuration.IsTruthy(res))
{
return(EvaluateToken(token.Right, configuration));
}
return(res);
}
case "||": // Logical OR
{
var res = EvaluateToken(token.Left, configuration);
if (!configuration.IsTruthy(res))
{
return(EvaluateToken(token.Right, configuration));
}
return(res);
}
}
break;
}
throw new Exception("An unexpected error occurred while evaluating expression");
}
internal static Token BuildTree(List <Token> tokens, EvalConfiguration configuration)
{
var order = configuration.OperatorOrder;
int orderCount = order.Length;
var prefixOps = configuration.PrefixOperators;
var suffixOps = configuration.SuffixOperators;
for (int i = orderCount - 1; i >= 0; i--)
{
var cs = order[i];
int pos;
string op;
LastIndexOfOpArray(tokens, cs, configuration, out pos, out op);
if (pos != -1)
{
var token = tokens[pos];
List <Token> left;
List <Token> right;
if (prefixOps.Contains(op) || suffixOps.Contains(op))
{
left = null;
right = null;
if (prefixOps.Contains(op) && pos == 0)
{
right = tokens.GetRange(pos + 1, tokens.Count - (pos + 1));
}
else if (suffixOps.Contains(op) && pos > 0)
{
left = tokens.GetRange(0, pos);
}
if (left == null && right == null)
{
throw new Exception("Operator " + token.Value.ToString() + " is unexpected at index " + token.Position);
}
}
else
{
left = tokens.GetRange(0, pos);
right = tokens.GetRange(pos + 1, tokens.Count - (pos + 1));
if (left.Count == 0 && (op == "-" || op == "+"))
{
left = null;
}
}
if ((left != null && left.Count == 0) ||
(right != null && right.Count == 0))
{
throw new Exception("Invalid expression, missing operand");
}
if (left == null && op == "-")
{
left = new List <Token> {
new Token {
Type = TokenType.Number, Value = "0"
}
};
}
else if (left == null && op == "+")
{
return(BuildTree(right, configuration));
}
if (left != null)
{
token.Left = BuildTree(left, configuration);
}
if (right != null)
{
token.Right = BuildTree(right, configuration);
}
return(token);
}
}
if (tokens.Count > 1)
{
throw new Exception("Invalid expression, missing operand or operator at " + tokens[1].Position);
}
if (tokens.Count == 0)
{
throw new Exception("Invalid expression, missing operand or operator.");
}
var singleToken = tokens[0];
if (singleToken.Type == TokenType.Group)
{
singleToken = BuildTree(singleToken.Tokens, configuration);
}
else if (singleToken.Type == TokenType.Call)
{
singleToken.Arguments = new List <Token>();
for (int a = 0, arglen = singleToken.ArgumentsGroups.Count; a < arglen; a++)
{
if (singleToken.ArgumentsGroups[a].Count == 0)
{
singleToken.Arguments.Add(null);
}
else
{
singleToken.Arguments.Add(BuildTree(singleToken.ArgumentsGroups[a], configuration));
}
}
}
else if (singleToken.Type == TokenType.Comma)
{
throw new Exception("Unexpected character at index " + singleToken.Position);
}
return(singleToken);
}
internal static List <Token> TokenizeExpression(string expression, EvalConfiguration configuration)
{
var varNameChars = configuration.VarNameChars;
var tokens = new List <Token>();
int i = 0;
for (int len = expression.Length; i < len; i++)
{
var c = expression[i];
var isDigit = c >= '0' && c <= '9';
if (isDigit || c == '.')
{
// Starting a number
int nextIndex;
var parsedNumber = ParseNumber(expression, i, out nextIndex);
tokens.Add(new Token
{
Type = TokenType.Number,
Position = i,
Value = parsedNumber
});
i = nextIndex - 1;
continue;
}
var isVarChars = varNameChars.Contains(c);
if (isVarChars)
{
// Starting a variable name - can start only with A-Z_
var token = "";
while (i < len)
{
c = expression[i];
isVarChars = varNameChars.Contains(c);
if (!isVarChars)
{
break;
}
token += c;
i++;
}
tokens.Add(new Token
{
Type = TokenType.Var,
Position = i - token.Length,
Value = token
});
i--; // Step back to continue loop from correct place
continue;
}
if (c == '\'' || c == '\"')
{
int nextIndex;
var parsedString = ParseString(expression, i, false, true, out nextIndex);
tokens.Add(new Token
{
Type = TokenType.String,
Position = i,
Value = parsedString
});
i = nextIndex - 1;
continue;
}
if (c == '(')
{
tokens.Add(new Token
{
Type = TokenType.LeftParen,
Position = i
});
continue;
}
if (c == ')')
{
tokens.Add(new Token
{
Type = TokenType.RightParen,
Position = i
});
continue;
}
if (c == ',')
{
tokens.Add(new Token
{
Type = TokenType.Comma,
Position = i
});
continue;
}
if (c == ' ' || c == '\t' || c == '\f' || c == '\r' || c == '\n')
{
// Whitespace, skip
continue;
}
var op = OpAtPosition(expression, i, configuration);
if (op != null)
{
tokens.Add(new Token
{
Type = TokenType.Op,
Position = i,
Value = op
});
i += op.Length - 1;
continue;
}
throw new FormatException("Unexpected token at index " + i);
}
return(tokens);
}
public static CompiledExpression Compile(string expression, EvalConfiguration configuration)
{
var tokens = TokenizeExpression(expression, configuration);
// Compact +-
for (int i = 1, len = tokens.Count; i < len; i++)
{
var token = tokens[i];
var prevToken = tokens[i - 1];
if (token.Type == TokenType.Op &&
(token.Value == "-" || token.Value == "+") &&
prevToken.Type == TokenType.Op &&
(prevToken.Value == "-" || prevToken.Value == "+"))
{
if (prevToken.Value != "+")
{
if (token.Value == "-")
{
token.Value = "+";
}
else
{
token.Value = "-";
}
}
tokens.RemoveAt(i - 1);
i--;
len = tokens.Count;
continue;
}
if (token.Type == TokenType.Number &&
prevToken.Type == TokenType.Op &&
(prevToken.Value == "-" || prevToken.Value == "+") &&
((i > 1 && tokens[i - 2].Type == TokenType.Op) || i == 1)
)
{
if (prevToken.Value == "-")
{
token.Value = prevToken.Value + token.Value;
}
tokens.RemoveAt(i - 1);
i--;
len = tokens.Count;
continue;
}
}
// Take care of groups (including function calls)
for (int i = 0, len = tokens.Count; i < len; i++)
{
var token = tokens[i];
if (token.Type == TokenType.LeftParen)
{
GroupTokens(tokens, i);
len = tokens.Count;
i--;
}
}
// Build the tree
var tree = BuildTree(tokens, configuration);
return(new CompiledExpression {
Root = tree, Configuration = configuration
});
}
