private Ast.Expression ParseExpression(bool allowIndirectIdentifier = false)
{
Ast.Expression expression = null;
var token = currentToken;
switch (token.Type)
{
case TokenType.Identifier:
if (token.Value == "true")
expression = new Ast.LiteralExpression(new Ast.Literal(true) {Span = token.Span}) {Span = token.Span};
else if (token.Value == "false")
expression = new Ast.LiteralExpression(new Ast.Literal(false) {Span = token.Span}) {Span = token.Span};
else if (string.Compare(token.Value, "null", StringComparison.OrdinalIgnoreCase) == 0)
expression = new Ast.LiteralExpression(new Ast.Literal(null) {Span = token.Span}) {Span = token.Span};
else if (token.Value == "compile")
{
expression = ParseCompileExpression();
}
else
{
var nextIdentifier = ParseIdentifier(token, true);
// check next token
BeginPreviewToken();
var nextToken = NextToken();
EndPreviewToken();
switch (nextToken.Type)
{
case TokenType.LeftParent:
var methodExpression = ParseMethodExpression();
methodExpression.Name = nextIdentifier;
expression = methodExpression;
break;
case TokenType.Equal:
var assignExpression = ParseAssignExpression();
assignExpression.Name = nextIdentifier;
expression = assignExpression;
break;
default:
expression = new Ast.IdentifierExpression(nextIdentifier) {Span = token.Span};
break;
}
}
break;
case TokenType.LeftParent:
expression = ParseArrayInitializerExpression(TokenType.RightParent);
//expression = ParseExpression();
//ExpectNext(TokenType.RightParent);
break;
case TokenType.String:
// TODO doesn't support escaped strings
var str = token.Value.Substring(1, token.Value.Length - 2);
// Temporary escape
str = str.Replace("\\r\\n", "\r\n");
str = str.Replace("\\n", "\n");
str = str.Replace("\\t", "\t");
expression = new Ast.LiteralExpression(new Ast.Literal(str) {Span = token.Span}) {Span = token.Span};
break;
case TokenType.Number:
var numberStr = token.Value.Replace(" ", "");
object numberValue;
if (numberStr.EndsWith("f", false, CultureInfo.InvariantCulture) || numberStr.Contains("e") || numberStr.Contains("E") || numberStr.Contains("."))
{
var floatStr = numberStr.TrimEnd('f');
numberValue = float.Parse(floatStr, NumberStyles.Float, CultureInfo.InvariantCulture);
}
else
{
numberValue = int.Parse(numberStr, NumberStyles.Integer, CultureInfo.InvariantCulture);
}
expression = new Ast.LiteralExpression(new Ast.Literal(numberValue) {Span = token.Span}) {Span = token.Span};
break;
case TokenType.Hexa:
var intValue = int.Parse(token.Value.Substring(2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
expression = new Ast.LiteralExpression(new Ast.Literal(intValue) {Span = token.Span}) {Span = token.Span};
break;
case TokenType.LeftCurlyBrace:
expression = ParseArrayInitializerExpression(TokenType.RightCurlyBrace);
break;
default:
if (token.Type == TokenType.LessThan && allowIndirectIdentifier)
{
NextToken();
var identifierExpression = ParseExpression() as Ast.IdentifierExpression;
bool isClosedIndirect = ExpectNext(TokenType.GreaterThan);
if (identifierExpression == null)
{
Logger.Error("Unexpected expression inside indirect reference.", token.Span);
}
else
{
identifierExpression.Name.IsIndirect = isClosedIndirect;
expression = identifierExpression;
}
}
else
{
Logger.Error("Unexpected token [{0}]. Expecting tokens ['identifier', 'string', 'number', '{{']", currentToken.Span, currentToken);
}
break;
}
return expression;
}
private Ast.Expression ParseExpression(bool allowIndirectIdentifier = false)
{
Ast.Expression expression = null;
var token = currentToken;
switch (token.Type)
{
case TokenType.Identifier:
if (token.Value == "true")
{
expression = new Ast.LiteralExpression(new Ast.Literal(true)
{
Span = token.Span
})
{
Span = token.Span
}
}
;
else if (token.Value == "false")
{
expression = new Ast.LiteralExpression(new Ast.Literal(false)
{
Span = token.Span
})
{
Span = token.Span
}
}
;
else if (string.Compare(token.Value, "null", StringComparison.OrdinalIgnoreCase) == 0)
{
expression = new Ast.LiteralExpression(new Ast.Literal(null)
{
Span = token.Span
})
{
Span = token.Span
}
}
;
else if (token.Value == "compile")
{
expression = ParseCompileExpression();
}
else
{
var nextIdentifier = ParseIdentifier(token, true);
// check next token
BeginPreviewToken();
var nextToken = NextToken();
EndPreviewToken();
switch (nextToken.Type)
{
case TokenType.LeftParent:
var methodExpression = ParseMethodExpression();
methodExpression.Name = nextIdentifier;
expression = methodExpression;
break;
case TokenType.Equal:
var assignExpression = ParseAssignExpression();
assignExpression.Name = nextIdentifier;
expression = assignExpression;
break;
default:
expression = new Ast.IdentifierExpression(nextIdentifier)
{
Span = token.Span
};
break;
}
}
break;
case TokenType.LeftParent:
expression = ParseArrayInitializerExpression(TokenType.RightParent);
//expression = ParseExpression();
//ExpectNext(TokenType.RightParent);
break;
case TokenType.String:
// TODO doesn't support escaped strings
var str = token.Value.Substring(1, token.Value.Length - 2);
// Temporary escape
str = str.Replace("\\r\\n", "\r\n");
str = str.Replace("\\n", "\n");
str = str.Replace("\\t", "\t");
expression = new Ast.LiteralExpression(new Ast.Literal(str)
{
Span = token.Span
})
{
Span = token.Span
};
break;
case TokenType.Number:
var numberStr = token.Value.Replace(" ", "");
object numberValue;
if (numberStr.EndsWith("f", false, CultureInfo.InvariantCulture) || numberStr.Contains("e") || numberStr.Contains("E") || numberStr.Contains("."))
{
var floatStr = numberStr.TrimEnd('f');
numberValue = float.Parse(floatStr, NumberStyles.Float, CultureInfo.InvariantCulture);
}
else
{
numberValue = int.Parse(numberStr, NumberStyles.Integer, CultureInfo.InvariantCulture);
}
expression = new Ast.LiteralExpression(new Ast.Literal(numberValue)
{
Span = token.Span
})
{
Span = token.Span
};
break;
case TokenType.Hexa:
var intValue = int.Parse(token.Value.Substring(2), NumberStyles.HexNumber, CultureInfo.InvariantCulture);
expression = new Ast.LiteralExpression(new Ast.Literal(intValue)
{
Span = token.Span
})
{
Span = token.Span
};
break;
case TokenType.LeftCurlyBrace:
expression = ParseArrayInitializerExpression(TokenType.RightCurlyBrace);
break;
default:
if (token.Type == TokenType.LessThan && allowIndirectIdentifier)
{
NextToken();
var identifierExpression = ParseExpression() as Ast.IdentifierExpression;
bool isClosedIndirect = ExpectNext(TokenType.GreaterThan);
if (identifierExpression == null)
{
Logger.Error("Unexpected expression inside indirect reference.", token.Span);
}
else
{
identifierExpression.Name.IsIndirect = isClosedIndirect;
expression = identifierExpression;
}
}
else
{
Logger.Error("Unexpected token [{0}]. Expecting tokens ['identifier', 'string', 'number', '{{']", currentToken.Span, currentToken);
}
break;
}
return(expression);
}