private ExpressionFnOuter Lexer(TokenStream stream)
{
if (stream.TryTokenType(ExpressionTokenType.Element, out ExpressionToken token))
{
return(Element(stream, token));
}
if (stream.TryTokenType(ExpressionTokenType.String, out token))
{
return(String(token));
}
if (stream.TryTokenType(ExpressionTokenType.Numeric, out token))
{
return(Numeric(token));
}
return(null);
}
private ExpressionFnOuter Inner(TokenStream stream)
{
ExpressionFnOuter result = null;
if (stream.TryTokenType(ExpressionTokenType.String, out ExpressionToken token))
{
return(String(token));
}
if (stream.TryTokenType(ExpressionTokenType.Numeric, out token))
{
return(Numeric(token));
}
if (stream.TryTokenType(ExpressionTokenType.Element, out token))
{
result = Element(stream, token);
}
return(result);
}
private ExpressionFnOuter Element(TokenStream stream, ExpressionToken element)
{
ExpressionFnOuter result = null;
// function
if (stream.Skip(ExpressionTokenType.GroupStart))
{
if (!_Functions.TryDescriptor(element.Content, out IFunctionDescriptor descriptor))
{
throw new NotImplementedException(string.Format(PSRuleResources.FunctionNotFound, element.Content));
}
var fnParams = new List <ExpressionFnOuter>();
while (!stream.Skip(ExpressionTokenType.GroupEnd))
{
fnParams.Add(Inner(stream));
}
var aParams = fnParams.ToArray();
result = (context) => descriptor.Invoke(context, aParams);
while (stream.TryTokenType(ExpressionTokenType.IndexStart, out ExpressionToken token) || stream.TryTokenType(ExpressionTokenType.Property, out token))
{
if (token.Type == ExpressionTokenType.IndexStart)
{
// Invert: index(fn1(p1, p2), 0)
var inner = Inner(stream);
ExpressionFnOuter outer = AddIndex(result, inner);
result = outer;
stream.Skip(ExpressionTokenType.IndexEnd);
}
else if (token.Type == ExpressionTokenType.Property)
{
// Invert: property(fn1(p1, p2), "name")
ExpressionFnOuter outer = AddProperty(result, token.Content);
result = outer;
}
}
}
// integer
else
{
result = (context) => element.Content;
}
return(result);
}