private string ReadName(SimpleParser parser)
{
using (var la = parser.LookAround())
{
if (!parser.ReadChar('_') &&
!parser.ReadChar(UnicodeCategory.LowercaseLetter) &&
!parser.ReadChar(UnicodeCategory.UppercaseLetter))
{
return(null);
}
parser.ReadWhileCharOrEof(IsIdentifierChar);
la.Success();
return(la.Text);
}
}
private static bool ReadListSeparator(SimpleParser parser)
{
parser.SkipSpaces();
return(parser.ReadChar(','));
}
/// <summary> /// Reads the code using a SimpleParser object, and using a previously parsed result, /// and then returns a new object representing the result from parsing the current code. /// </summary> /// <param name="parser">The parser object used to read the code.</param> /// <param name="prevData">Previously parsed result. This is used to chain results together.</param> /// <returns>Returns an object that results from parsing the code.</returns> public abstract object Read(SimpleParser parser, object prevData);
/// <summary>
/// Reads the code trying to extract the AST from it.
/// </summary>
/// <param name="parser">The parser object used to read the code.</param>
/// <param name="prevData">Previously parsed result. This is used to chain results together.</param>
/// <returns>Returns an object that results from parsing the code.</returns>
public override object Read(SimpleParser parser, object prevData)
{
var prevExecutor = prevData as INode;
parser.SkipSpaces();
if (prevData == null)
{
var name = this.ReadName(parser);
// this is a direct method call in the root
var call = ReadMethodCall(parser, null, name);
if (call != null)
{
return(call);
}
// this is a global property
if (!string.IsNullOrWhiteSpace(name))
{
var typeReference = parser.StaticTypes.SingleOrDefault(t => t.Name == name);
if (typeReference != null)
{
return(typeReference);
}
return(new PropertyGet {
Name = name, Element = null
});
}
// this is an array construct
if (parser.ReadChar('{'))
{
var values = parser.ReadList <ValueBuilder, INode>(ReadListSeparator);
if (values.Count > 0)
{
parser.SkipSpaces();
if (!parser.ReadChar('}'))
{
return(new Exception("Unterminated array construct."));
}
return(new ArrayConstruct {
Values = values
});
}
}
// this is a precedence operator
if (parser.ReadChar('('))
{
var value = parser.Read <ValueBuilder, INode>();
if (value == null)
{
return(new Exception("Syntax error."));
}
parser.SkipSpaces();
if (!parser.ReadChar(')'))
{
return(new Exception("Unterminated precedence construct."));
}
return(value);
}
// this is a number literal
var number = parser.ReadWhileCharOrEof(char.IsNumber);
if (number.Length > 0)
{
return new NumberLiteral {
Data = number
}
}
;
// this is a string literal
if (parser.ReadChar('"'))
{
var strBuilder = new StringBuilder();
while (true)
{
strBuilder.Append(parser.ReadWhileCharOrEof(ch => ch != '\\' && ch != '"'));
if (parser.Eof)
{
return(new InvalidOperationException("String literal not terminated."));
}
if (parser.ReadChar('\\'))
{
if (parser.ReadChar('0'))
{
strBuilder.Append('\0');
}
else if (parser.ReadChar('n'))
{
strBuilder.Append('\n');
}
else if (parser.ReadChar('r'))
{
strBuilder.Append('\r');
}
else if (parser.ReadChar('\\'))
{
strBuilder.Append('\\');
}
else if (parser.ReadChar('"'))
{
strBuilder.Append('"');
}
else
{
return(new InvalidOperationException("Escape sequence not recognized."));
}
}
if (parser.ReadChar('"'))
{
break;
}
}
return(new StringLiteral {
Data = strBuilder.ToString()
});
}
}
else
{
if (parser.ReadChar('.'))
{
var name = this.ReadName(parser);
// this is a direct method call in the previous element
var call = ReadMethodCall(parser, prevData, name);
if (call != null)
{
return(call);
}
if (!string.IsNullOrWhiteSpace(name))
{
return new PropertyGet {
Name = name, Element = prevExecutor
}
}
;
}
// indexer property
if (parser.ReadChar('['))
{
var indexValues = parser.ReadList <ValueBuilder, INode>(ReadListSeparator);
if (indexValues.Count == 0)
{
return(new Exception("Index is missing."));
}
parser.SkipSpaces();
if (!parser.ReadChar(']'))
{
return(new Exception("Unterminated indexer."));
}
return(new IndexerGet {
Element = prevExecutor, Indexes = indexValues
});
}
// this only happens when calling a delegate
// direct method calls never fall here
if (parser.ReadChar('('))
{
var paramValues = parser.ReadList <ValueBuilder, INode>(ReadListSeparator);
parser.SkipSpaces();
if (parser.ReadChar(')'))
{
return new Call {
Element = prevExecutor, Name = "Invoke", Parameters = paramValues
}
}
;
}
if (parser.ReadChar('?'))
{
var trueValue = parser.Read <ValueBuilder, INode>();
parser.SkipSpaces();
if (!parser.ReadChar(':'))
{
throw new Exception("Missing ':' for ternary operator a?b:c.");
}
parser.SkipSpaces();
var falseValue = parser.Read <ValueBuilder, INode>();
return(new TernaryInlineIf {
Condition = prevExecutor, TrueValue = trueValue, FalseValue = falseValue
});
}
var binOp = parser.ReadAnyStringAlternative("==", "!=", ">", "<", ">=", "<=", "&&", "||");
if (binOp != null)
{
var valueB = parser.Read <ValueBuilder, INode>();
return(new BinaryBoolOps {
ValueA = prevExecutor, ValueB = valueB, Operator = binOp
});
}
}
return(null);
}
/// <summary>
/// Initializes a new instance of the <see cref="LookAroundDisposer"/> class.
/// </summary>
/// <param name="parser">
/// The SimpleParser object that should be reverted to the current state, if the parsing block fails.
/// </param>
public LookAroundDisposer(SimpleParser parser)
{
this.parser = parser;
this.oldPosition = parser.Position;
}