private ExpressionToken ParseExpression(
Int32?line,
Int32?column,
String value,
String[] allowedContext,
out Exception ex)
{
var trimmed = value.Trim();
// Check if the value is empty
if (String.IsNullOrEmpty(trimmed))
{
ex = new ArgumentException(TemplateStrings.ExpectedExpression());
return(null);
}
// Try to find a matching directive
List <String> parameters;
if (MatchesDirective(trimmed, TemplateConstants.InsertDirective, 0, out parameters, out ex))
{
return(new InsertExpressionToken(m_fileId, line, column));
}
else if (ex != null)
{
return(null);
}
// Check if the value is an expression
if (!ExpressionToken.IsValidExpression(trimmed, allowedContext, out ex))
{
return(null);
}
// Return the expression
return(new BasicExpressionToken(m_fileId, line, column, trimmed));
}