private Expression Compile(bool multiple)
{
if (CurrentToken == null)
{
return(null);
}
List <Expression> expressions = new List <Expression>();
bool braced = CurrentToken.IsOpenBrace;
if (braced)
{
MoveNext();
multiple = true;
}
IfExpression ifExpression = null;
while (CurrentToken != null)
{
var token = CurrentToken;
switch (token.TokenType)
{
case TokenType.CloseBrace:
{
if (!braced)
{
throw new LexerException(TokenPosition.Unknown, token.Text);
}
MoveNext();
multiple = false;
break;
}
case TokenType.ForEach:
{
MoveNext();
InExpression expression = CompileBracketed() as InExpression;
if (expression == null)
{
throw new LexerException("foreach syntax error", token.TokenPosition, token.Text);
}
ForEachExpression forEach = new ForEachExpression(TokenPosition.Unknown);
forEach.Iterator = expression.Variable;
forEach.Expression = expression.Expression;
forEach.Body = Compile(false);
expressions.Add(forEach);
break;
}
case TokenType.If:
{
MoveNext();
var expr = CompileBracketed();
ifExpression = new IfExpression(TokenPosition.Unknown, expr);
ifExpression.TrueExpression = Compile(false);
expressions.Add(ifExpression);
break;
}
case TokenType.Else:
{
MoveNext();
if (ifExpression != null)
{
ifExpression.FalseExpression = Compile(false);
ifExpression = null;
}
break;
}
case TokenType.Return:
{
MoveNext();
Expression expression = Compile(multiple: false);
expressions.Add(new ReturnExpression(TokenPosition.Unknown, expression));
break;
}
case TokenType.FunctionDefinition:
{
MoveNext();
var functionExpression = new FunctionDefinitionExpression(TokenPosition.Unknown);
if (CurrentToken.TokenType != TokenType.Term)
{
throw new LexerException("function name expected", TokenPosition.Unknown, CurrentToken.Text);
}
functionExpression.Name = CurrentToken.Text;
MoveNext();
int level = 0;
int start = CurrentIndex - 1;
int end = -1;
while (CurrentToken != null)
{
if (CurrentToken.IsLeftParen)
{
level++;
}
else if (CurrentToken.IsRightParen)
{
if (level > 0)
{
level--;
if (level == 0)
{
end = CurrentIndex;
break;
}
}
}
MoveNext();
}
CurrentIndex = start;
var parameters = CompileStatement(end) as CallExpression;
functionExpression.ParameterNames = (from p in parameters.Parameters select((VariableExpression)p).VarName).ToArray();
functionExpression.Body = Compile(false);
expressions.Add(functionExpression);
}
break;
default:
expressions.Add(CompileStatement());
break;
}
if (!multiple)
{
break;
}
}
if (expressions.Count > 1)
{
return(new SequenceExpression(TokenPosition.Unknown, expressions.ToArray()));
}
if (expressions.Count == 1)
{
return(expressions[0]);
}
return(null);
}
public override ValueExpression Evaluate(IParserContext context)
{
object methodObject = MethodExpression.Evaluate(context).Value;
ValueExpression[] parameters = EvaluateExpressionArray(Parameters, context);
Type[] parameterTypes = parameters.ConvertAll(expr => expr.Type);
object[] parameterValues = parameters.ConvertAll(expr => expr.Value);
if (methodObject is MethodDefinition)
{
Type returnType;
return(Exp.Value(TokenPosition, ((MethodDefinition)methodObject).Invoke(parameterTypes, parameterValues, out returnType), returnType));
}
if (methodObject is ConstructorInfo[])
{
ConstructorInfo[] constructors = (ConstructorInfo[])methodObject;
MethodBase method = LazyBinder.SelectBestMethod(constructors, parameterTypes, BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance);
if (method == null)
{
throw new ExpressionEvaluationException("No match found for constructor " + constructors[0].Name, this);
}
object value = LazyBinder.Invoke(method, parameterValues);
//object value = ((ConstructorInfo)method).Invoke(parameterValues);
return(Exp.Value(TokenPosition, value, method.DeclaringType));
}
if (methodObject is Delegate[])
{
Delegate[] delegates = (Delegate[])methodObject;
MethodBase[] methods = delegates.ConvertAll <Delegate, MethodBase>(d => d.GetMethodInfo());
MethodBase method = LazyBinder.SelectBestMethod(methods, parameterTypes, BindingFlags.Public | BindingFlags.Static | BindingFlags.Instance);
if (method == null)
{
throw new ExpressionEvaluationException("No match found for delegate " + MethodExpression, this);
}
object value = LazyBinder.Invoke(method, delegates[Array.IndexOf(methods, method)].Target, parameterValues);
return(Exp.Value(TokenPosition, value, ((MethodInfo)method).ReturnType));
}
if (methodObject is Delegate)
{
Delegate method = (Delegate)methodObject;
MethodInfo methodInfo = method.GetMethodInfo();
object value = methodInfo.Invoke(method.Target, parameterValues);
return(new ValueExpression(TokenPosition, value, methodInfo.ReturnType));
}
if (methodObject is FunctionDefinitionExpression)
{
FunctionDefinitionExpression func = (FunctionDefinitionExpression)methodObject;
var functionContext = context.CreateLocal();
for (int i = 0; i < parameterValues.Length; i++)
{
functionContext.Set(func.ParameterNames[i], parameterValues[i]);
}
return(func.Body.Evaluate(functionContext));
}
throw new ExpressionEvaluationException(MethodExpression + " is not a function", this);
}
public FunctionValueExpression(TokenPosition position, FunctionDefinitionExpression function) : base(position, function, typeof(FunctionDefinitionExpression))
{
}