private Expression ParseEntityWithoutSuffixChain(TokenStream tokens, TopLevelConstruct owner)
{
string next = tokens.PeekValue();
if (next == null)
{
tokens.ThrowEofException();
}
if (next == this.parser.Keywords.NULL)
{
return(new NullConstant(tokens.Pop(), owner));
}
if (next == this.parser.Keywords.TRUE)
{
return(new BooleanConstant(tokens.Pop(), true, owner));
}
if (next == this.parser.Keywords.FALSE)
{
return(new BooleanConstant(tokens.Pop(), false, owner));
}
Token peekToken = tokens.Peek();
if (next.StartsWith("'"))
{
return(new StringConstant(tokens.Pop(), StringConstant.ParseOutRawValue(peekToken), owner));
}
if (next.StartsWith("\""))
{
return(new StringConstant(tokens.Pop(), StringConstant.ParseOutRawValue(peekToken), owner));
}
if (next == this.parser.Keywords.NEW)
{
return(this.ParseInstantiate(tokens, owner));
}
char firstChar = next[0];
if (VARIABLE_STARTER.Contains(firstChar))
{
Token varToken = tokens.Pop();
return(new Variable(varToken, varToken.Value, owner));
}
if (firstChar == '[')
{
Token bracketToken = tokens.PopExpected("[");
List <Expression> elements = new List <Expression>();
bool previousHasCommaOrFirst = true;
while (!tokens.PopIfPresent("]"))
{
if (!previousHasCommaOrFirst)
{
tokens.PopExpected("]"); // throws appropriate error
}
elements.Add(Parse(tokens, owner));
previousHasCommaOrFirst = tokens.PopIfPresent(",");
}
return(new ListDefinition(bracketToken, elements, owner));
}
if (firstChar == '{')
{
Token braceToken = tokens.PopExpected("{");
List <Expression> keys = new List <Expression>();
List <Expression> values = new List <Expression>();
bool previousHasCommaOrFirst = true;
while (!tokens.PopIfPresent("}"))
{
if (!previousHasCommaOrFirst)
{
tokens.PopExpected("}"); // throws appropriate error
}
keys.Add(Parse(tokens, owner));
tokens.PopExpected(":");
values.Add(Parse(tokens, owner));
previousHasCommaOrFirst = tokens.PopIfPresent(",");
}
return(new DictionaryDefinition(braceToken, keys, values, owner));
}
if (next.Length > 2 && next.Substring(0, 2) == "0x")
{
Token intToken = tokens.Pop();
int intValue = IntegerConstant.ParseIntConstant(intToken, intToken.Value);
return(new IntegerConstant(intToken, intValue, owner));
}
if (ParserContext.IsInteger(next))
{
Token numberToken = tokens.Pop();
string numberValue = numberToken.Value;
if (tokens.IsNext("."))
{
Token decimalToken = tokens.Pop();
if (decimalToken.HasWhitespacePrefix)
{
throw new ParserException(decimalToken, "Decimals cannot have whitespace before them.");
}
Token afterDecimal = tokens.Pop();
if (afterDecimal.HasWhitespacePrefix)
{
throw new ParserException(afterDecimal, "Cannot have whitespace after the decimal.");
}
if (!ParserContext.IsInteger(afterDecimal.Value))
{
throw new ParserException(afterDecimal, "Decimal must be followed by an integer.");
}
numberValue += "." + afterDecimal.Value;
double floatValue = FloatConstant.ParseValue(numberToken, numberValue);
return(new FloatConstant(numberToken, floatValue, owner));
}
int intValue = IntegerConstant.ParseIntConstant(numberToken, numberToken.Value);
return(new IntegerConstant(numberToken, intValue, owner));
}
if (tokens.IsNext("."))
{
Token dotToken = tokens.PopExpected(".");
string numberValue = "0.";
Token postDecimal = tokens.Pop();
if (postDecimal.HasWhitespacePrefix || !ParserContext.IsInteger(postDecimal.Value))
{
throw new ParserException(dotToken, "Unexpected dot.");
}
numberValue += postDecimal.Value;
double floatValue;
if (Util.ParseDouble(numberValue, out floatValue))
{
return(new FloatConstant(dotToken, floatValue, owner));
}
throw new ParserException(dotToken, "Invalid float literal.");
}
throw new ParserException(tokens.Peek(), "Encountered unexpected token: '" + tokens.PeekValue() + "'");
}
public Expression Parse(TokenStream tokens, TopLevelConstruct owner)
{
return(ParseTernary(tokens, owner));
}
private Expression ParseEntity(TokenStream tokens, TopLevelConstruct owner)
{
Expression root;
if (tokens.PopIfPresent("("))
{
root = this.Parse(tokens, owner);
tokens.PopExpected(")");
}
else
{
root = ParseEntityWithoutSuffixChain(tokens, owner);
}
bool anySuffixes = true;
while (anySuffixes)
{
if (tokens.IsNext("."))
{
Token dotToken = tokens.Pop();
Token stepToken = tokens.Pop();
// HACK alert: "class" is a valid field on a class.
// ParserVerifyIdentifier is invoked downstream for non-resolved fields.
if (stepToken.Value != this.parser.Keywords.CLASS)
{
this.parser.VerifyIdentifier(stepToken);
}
root = new DotStep(root, dotToken, stepToken, owner);
}
else if (tokens.IsNext("["))
{
Token openBracket = tokens.Pop();
List <Expression> sliceComponents = new List <Expression>();
if (tokens.IsNext(":"))
{
sliceComponents.Add(null);
}
else
{
sliceComponents.Add(Parse(tokens, owner));
}
for (int i = 0; i < 2; ++i)
{
if (tokens.PopIfPresent(":"))
{
if (tokens.IsNext(":") || tokens.IsNext("]"))
{
sliceComponents.Add(null);
}
else
{
sliceComponents.Add(Parse(tokens, owner));
}
}
}
tokens.PopExpected("]");
if (sliceComponents.Count == 1)
{
Expression index = sliceComponents[0];
root = new BracketIndex(root, openBracket, index, owner);
}
else
{
root = new ListSlice(root, sliceComponents, openBracket, owner);
}
}
else if (tokens.IsNext("("))
{
Token openParen = tokens.Pop();
List <Expression> args = new List <Expression>();
while (!tokens.PopIfPresent(")"))
{
if (args.Count > 0)
{
tokens.PopExpected(",");
}
args.Add(Parse(tokens, owner));
}
root = new FunctionCall(root, openParen, args, owner);
}
else if (tokens.IsNext(this.parser.Keywords.IS))
{
Token isToken = tokens.Pop();
Token classToken = tokens.Pop();
string className = this.parser.PopClassNameWithFirstTokenAlreadyPopped(tokens, classToken);
root = new IsComparison(root, isToken, classToken, className, owner);
}
else
{
anySuffixes = false;
}
}
return(root);
}
/// <summary>
/// Parser for Predicate
/// </summary>
/// <returns>Parsed Predicate</returns>
public Predicate ParsePredicate()
{
Predicate predicate = null; //Empty predicate
if (TokenStream.HasNext() && TokenStream.Peek(1).GetValue().ToString() == "!")
{ //Not Predicate
NotPredicate notPredicate = new NotPredicate();
//Skip ! token
NextToken("!", "! predicate", '!');
//Parse predicate after !
notPredicate.SetPredicate(ParsePredicate());
predicate = notPredicate;
}
else
{ //Other predicates exists out of an expression
Expression expression = expressionParser.ParseExpression();
if (TokenStream.HasNext() && TokenStream.Peek(1).GetValue().ToString() == ".")
{ //IsPredicate
predicate = ParseIsPredicate(expression);
}
else
{ //ExpressionPredicate
predicate = ParseExpressionPredicate(expression);
}
}
//Check for && or || predicates
if (TokenStream.HasNext() && TokenStream.Peek(1).GetValue().ToString() == "&" && TokenStream.Peek(2).GetValue().ToString() == "&")
{ //AndPredicate
return(ParseAndPredicate(predicate));
}
else if (TokenStream.HasNext() && TokenStream.Peek(1).GetValue().ToString() == "|" && TokenStream.Peek(2).GetValue().ToString() == "|")
{ //OrPredicate
return(ParseOrPredicate(predicate));
}
return(predicate);
}