public static AST.INode Parse(CharStream stream)
{
var startingPos = stream.Position;
try
{
AST.INode root;
if(!Property.PeekAndParse(stream, out root)) {
root = IdentifierExpression.Parse(stream);
}
stream.SkipString("::");
// we either have an expression or a simple identifier
AST.INode identifier;
if (stream.SkipIfPossible('['))
{
identifier = Expression.Parse(stream);
stream.SkipCharacter(']');
} else
{
identifier = new AST.Identifier(Identifier.Parse(stream, false));
}
// We can also have optionally a property expression,
// starting with a simple identifier or straight away with an expression
AST.PropertyExpression propertyExpression = null;
if (stream.SkipIfPossible('.'))
{
propertyExpression = Property.Parse(stream) as AST.PropertyExpression;
}
else if (stream.SkipIfPossible('['))
{
var expression = Expression.Parse(stream);
propertyExpression = new AST.PropertyExpression(expression);
stream.SkipCharacter(']');
Property.Parse(stream, propertyExpression);
}
return new AST.AttributeExpression(root, identifier, propertyExpression);
} catch (Exception e)
{
string msg = String.Format(
"something went wrong parsing an <property_expression> starting at {0}",
stream.ComputeDetailedPosition(startingPos));
throw new Exceptions.ParseException(msg, e);
}
}
public static AST.INode Parse(CharStream stream, AST.PropertyExpression property = null)
{
var startingPos = stream.Position;
try
{
if (property == null)
{
var obj = IdentifierExpression.Parse(stream);
property = new AST.PropertyExpression(obj);
}
char c;
// can be either a simple identifier ('.') or expression ('[')
while (stream.SkipAnyIfPossible(new char[] {'.', '['}, out c))
{
if (c == '.')
{
property.Add(Identifier.Parse(stream, false));
} else
{
WhiteSpace.Parse(stream, true);
property.Add(Expression.Parse(stream));
WhiteSpace.Parse(stream, true);
stream.SkipCharacter(']');
}
}
return property;
} catch (Exception e)
{
string msg = String.Format(
"something went wrong parsing an <property_expression> starting at {0}",
stream.ComputeDetailedPosition(startingPos));
throw new Exceptions.ParseException(msg, e);
}
}