/// <summary>
/// Determines if the tokenizer is pointing at a parameter list for an anonymous function.
/// </summary>
internal static bool IsAnonymousParameterList(PositionalTokenizer tokenizer)
{
var result = false;
tokenizer.PushState();
if (tokenizer.Match("("))
{
tokenizer.SkipWhitespace();
do
{
tokenizer.ReadIdentifier();
tokenizer.SkipWhitespace();
if (tokenizer.NextChar != ',')
{
break;
}
tokenizer.Advance();
tokenizer.SkipWhitespace();
} while (true);
if (tokenizer.Match(")"))
{
tokenizer.SkipWhitespace();
result = (tokenizer.NextChar == '{' || tokenizer.Match("=>"));
}
}
tokenizer.PopState();
return(result);
}
/// <summary>
/// Parses a for loop.
/// </summary>
/// <remarks>
/// Assumes the 'for' keyword has already been consumed.
/// </remarks>
internal static ExpressionBase Parse(PositionalTokenizer tokenizer, int line = 0, int column = 0)
{
ExpressionBase.SkipWhitespace(tokenizer);
var keywordFor = new KeywordExpression("for", line, column);
line = tokenizer.Line;
column = tokenizer.Column;
var iteratorName = tokenizer.ReadIdentifier();
if (iteratorName.IsEmpty)
{
return(ParseError(tokenizer, "Invalid function name", line, column));
}
var iterator = new VariableDefinitionExpression(iteratorName.ToString(), line, column);
ExpressionBase.SkipWhitespace(tokenizer);
line = tokenizer.Line;
column = tokenizer.Column;
if (!tokenizer.Match("in"))
{
return(ParseError(tokenizer, "Expected 'in' after loop variable"));
}
var keywordIn = new KeywordExpression("in", line, column);
var range = ExpressionBase.Parse(tokenizer);
if (range.Type == ExpressionType.ParseError)
{
return(range);
}
var loop = new ForExpression(iterator, range);
var error = ExpressionBase.ParseStatementBlock(tokenizer, loop.Expressions);
if (error != null)
{
return(error);
}
loop._keywordFor = keywordFor;
loop._keywordIn = keywordIn;
loop.Line = keywordFor.Line;
loop.Column = keywordFor.Column;
loop.EndLine = tokenizer.Line;
loop.EndColumn = tokenizer.Column;
return(loop);
}
/// <summary>
/// Parses a function definition.
/// </summary>
/// <remarks>
/// Assumes the 'function' keyword has already been consumed.
/// </remarks>
internal static ExpressionBase Parse(PositionalTokenizer tokenizer, int line = 0, int column = 0)
{
var locationStart = new TextLocation(line, column); // location of 'function' keyword
ExpressionBase.SkipWhitespace(tokenizer);
line = tokenizer.Line;
column = tokenizer.Column;
var functionName = tokenizer.ReadIdentifier();
var functionNameVariable = new VariableDefinitionExpression(functionName.ToString(), line, column);
var function = new UserFunctionDefinitionExpression(functionNameVariable);
function.Location = new TextRange(locationStart.Line, locationStart.Column, 0, 0);
if (functionName.IsEmpty)
{
return(ExpressionBase.ParseError(tokenizer, "Invalid function name"));
}
return(function.Parse(tokenizer));
}
private static ExpressionBase ParseClauseCore(PositionalTokenizer tokenizer)
{
ExpressionBase clause;
switch (tokenizer.NextChar)
{
case '!':
tokenizer.Advance();
clause = ParseClause(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ConditionalExpression(null, ConditionalOperation.Not, clause));
case '(':
if (AnonymousUserFunctionDefinitionExpression.IsAnonymousParameterList(tokenizer))
{
return(AnonymousUserFunctionDefinitionExpression.ParseAnonymous(tokenizer));
}
tokenizer.Advance();
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
if (tokenizer.NextChar != ')')
{
if (tokenizer.NextChar == '\0')
{
return(ParseError(tokenizer, "No closing parenthesis found"));
}
return(ParseError(tokenizer, "Expected closing parenthesis, found: " + tokenizer.NextChar));
}
clause.IsLogicalUnit = true;
tokenizer.Advance();
return(clause);
case '"':
try
{
var stringValue = tokenizer.ReadQuotedString().ToString();
return(new StringConstantExpression(stringValue));
}
catch (InvalidOperationException ex)
{
return(ParseError(tokenizer, ex.Message));
}
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
return(ParseNumber(tokenizer, true));
case '-':
var tokenStart = tokenizer.Location;
tokenizer.Advance();
if (tokenizer.NextChar >= '0' && tokenizer.NextChar <= '9')
{
var result = ParseNumber(tokenizer, false);
var tokenEnd = result.Location.End;
switch (result.Type)
{
case ExpressionType.IntegerConstant:
result = new IntegerConstantExpression(-((IntegerConstantExpression)result).Value);
break;
case ExpressionType.FloatConstant:
result = new FloatConstantExpression(-((FloatConstantExpression)result).Value);
break;
default:
return(result);
}
result.Location = new TextRange(tokenStart, tokenEnd);
return(result);
}
return(ParseError(tokenizer, "Minus without value", tokenStart.Line, tokenStart.Column));
case '{':
tokenizer.Advance();
return(DictionaryExpression.Parse(tokenizer));
case '[':
tokenizer.Advance();
return(ParseArray(tokenizer));
default:
var line = tokenizer.Line;
var column = tokenizer.Column;
var identifier = tokenizer.ReadIdentifier();
if (identifier.IsEmpty)
{
var error = ParseError(tokenizer, "Unexpected character: " + tokenizer.NextChar);
tokenizer.Advance();
return(error);
}
SkipWhitespace(tokenizer);
if (identifier == "return")
{
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ReturnExpression(new KeywordExpression(identifier.ToString(), line, column), clause));
}
if (identifier == "function")
{
return(UserFunctionDefinitionExpression.Parse(tokenizer, line, column));
}
if (identifier == "for")
{
return(ForExpression.Parse(tokenizer, line, column));
}
if (identifier == "if")
{
return(IfExpression.Parse(tokenizer, line, column));
}
if (identifier == "true")
{
return(new BooleanConstantExpression(true, line, column));
}
if (identifier == "false")
{
return(new BooleanConstantExpression(false, line, column));
}
if (tokenizer.NextChar == '(')
{
tokenizer.Advance();
var parameters = new List <ExpressionBase>();
ParseParameters(tokenizer, parameters);
var functionCall = new FunctionCallExpression(new FunctionNameExpression(identifier.ToString(), line, column), parameters);
functionCall.Location = new TextRange(line, column, tokenizer.Line, tokenizer.Column - 1);
return(functionCall);
}
if (tokenizer.NextChar == '[')
{
IndexedVariableExpression parent = null;
do
{
tokenizer.Advance();
var index = ExpressionBase.Parse(tokenizer);
if (index.Type == ExpressionType.ParseError)
{
return(index);
}
SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ']')
{
return(ParseError(tokenizer, "Expecting closing bracket after index"));
}
tokenizer.Advance();
SkipWhitespace(tokenizer);
if (parent != null)
{
parent = new IndexedVariableExpression(parent, index);
}
else
{
parent = new IndexedVariableExpression(new VariableExpression(identifier.ToString(), line, column), index);
}
} while (tokenizer.NextChar == '[');
return(parent);
}
return(new VariableExpression(identifier.ToString(), line, column));
}
}
protected new ExpressionBase Parse(PositionalTokenizer tokenizer)
{
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != '(')
{
return(ExpressionBase.ParseError(tokenizer, "Expected '(' after function name", Name));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ')')
{
do
{
var line = tokenizer.Line;
var column = tokenizer.Column;
var parameter = tokenizer.ReadIdentifier();
if (parameter.IsEmpty)
{
return(ExpressionBase.ParseError(tokenizer, "Invalid parameter name", line, column));
}
var variableDefinition = new VariableDefinitionExpression(parameter.ToString(), line, column);
Parameters.Add(variableDefinition);
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar == '=')
{
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
var value = ExpressionBase.Parse(tokenizer);
if (value.Type == ExpressionType.ParseError)
{
return(ExpressionBase.ParseError(tokenizer, "Invalid default value for " + parameter.ToString(), value));
}
var scope = new InterpreterScope(AchievementScriptInterpreter.GetGlobalScope());
scope.Context = new TriggerBuilderContext(); // prevent errors passing memory references as default parameters
ExpressionBase evaluated;
if (!value.ReplaceVariables(scope, out evaluated))
{
return(ExpressionBase.ParseError(tokenizer, "Default value for " + parameter.ToString() + " is not constant", evaluated));
}
DefaultParameters[parameter.ToString()] = evaluated;
}
else if (DefaultParameters.Count > 0)
{
return(ExpressionBase.ParseError(tokenizer,
string.Format("Non-default parameter {0} appears after default parameters", parameter.ToString()), variableDefinition));
}
if (tokenizer.NextChar == ')')
{
break;
}
if (tokenizer.NextChar != ',')
{
return(ExpressionBase.ParseError(tokenizer, "Expected ',' or ')' after parameter name, found: " + tokenizer.NextChar));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
} while (true);
}
tokenizer.Advance(); // closing parenthesis
ExpressionBase.SkipWhitespace(tokenizer);
ExpressionBase expression;
if (tokenizer.Match("=>"))
{
return(ParseShorthandBody(tokenizer));
}
if (tokenizer.NextChar != '{')
{
return(ExpressionBase.ParseError(tokenizer, "Expected '{' after function declaration", Name));
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
bool seenReturn = false;
while (tokenizer.NextChar != '}')
{
expression = ExpressionBase.Parse(tokenizer);
if (expression.Type == ExpressionType.ParseError)
{
// the ExpressionTokenizer will capture the error, we should still return the incomplete FunctionDefinition
if (tokenizer is ExpressionTokenizer)
{
break;
}
// not an ExpressionTokenizer, just return the error
return(expression);
}
if (expression.Type == ExpressionType.Return)
{
seenReturn = true;
}
else if (seenReturn)
{
ExpressionBase.ParseError(tokenizer, "Expression after return statement", expression);
}
Expressions.Add(expression);
ExpressionBase.SkipWhitespace(tokenizer);
}
Location = new TextRange(Location.Start, tokenizer.Location);
tokenizer.Advance();
return(MakeReadOnly(this));
}
/// <summary>
/// Parses a function definition.
/// </summary>
/// <remarks>
/// Assumes the 'function' keyword has already been consumed.
/// </remarks>
internal static ExpressionBase Parse(PositionalTokenizer tokenizer, int line = 0, int column = 0)
{
var function = new FunctionDefinitionExpression();
function._keyword = new KeywordExpression("function", line, column);
ExpressionBase.SkipWhitespace(tokenizer);
line = tokenizer.Line;
column = tokenizer.Column;
var functionName = tokenizer.ReadIdentifier();
function.Name = new VariableDefinitionExpression(functionName.ToString(), line, column);
if (functionName.IsEmpty)
{
ExpressionBase.ParseError(tokenizer, "Invalid function name");
return(function);
}
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != '(')
{
ExpressionBase.ParseError(tokenizer, "Expected '(' after function name", function.Name);
return(function);
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ')')
{
do
{
line = tokenizer.Line;
column = tokenizer.Column;
var parameter = tokenizer.ReadIdentifier();
if (parameter.IsEmpty)
{
ExpressionBase.ParseError(tokenizer, "Invalid parameter name", line, column);
return(function);
}
function.Parameters.Add(new VariableDefinitionExpression(parameter.ToString(), line, column));
ExpressionBase.SkipWhitespace(tokenizer);
if (tokenizer.NextChar == ')')
{
break;
}
if (tokenizer.NextChar != ',')
{
ExpressionBase.ParseError(tokenizer, "Expected ',' or ')' after parameter name, found: " + tokenizer.NextChar);
return(function);
}
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
} while (true);
}
tokenizer.Advance(); // closing parenthesis
ExpressionBase.SkipWhitespace(tokenizer);
ExpressionBase expression;
if (tokenizer.Match("=>"))
{
ExpressionBase.SkipWhitespace(tokenizer);
expression = ExpressionBase.Parse(tokenizer);
if (expression.Type == ExpressionType.ParseError)
{
return(expression);
}
if (expression.Type == ExpressionType.Return)
{
return(new ParseErrorExpression("Return statement is implied by =>", ((ReturnExpression)expression).Keyword));
}
var returnExpression = new ReturnExpression(expression);
function.Expressions.Add(returnExpression);
return(function);
}
if (tokenizer.NextChar != '{')
{
ExpressionBase.ParseError(tokenizer, "Expected '{' after function declaration", function.Name);
return(function);
}
line = tokenizer.Line;
column = tokenizer.Column;
tokenizer.Advance();
ExpressionBase.SkipWhitespace(tokenizer);
bool seenReturn = false;
while (tokenizer.NextChar != '}')
{
expression = ExpressionBase.Parse(tokenizer);
if (expression.Type == ExpressionType.ParseError)
{
return(expression);
}
if (expression.Type == ExpressionType.Return)
{
seenReturn = true;
}
else if (seenReturn)
{
ExpressionBase.ParseError(tokenizer, "Expression after return statement", expression);
}
function.Expressions.Add(expression);
ExpressionBase.SkipWhitespace(tokenizer);
}
tokenizer.Advance();
return(function);
}
private static ExpressionBase ParseClauseCore(PositionalTokenizer tokenizer)
{
ExpressionBase clause;
switch (tokenizer.NextChar)
{
case '!':
tokenizer.Advance();
clause = ParseClause(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ConditionalExpression(null, ConditionalOperation.Not, clause));
case '(':
tokenizer.Advance();
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
if (tokenizer.NextChar != ')')
{
if (tokenizer.NextChar == '\0')
{
return(ParseError(tokenizer, "No closing parenthesis found"));
}
return(ParseError(tokenizer, "Expected closing parenthesis, found: " + tokenizer.NextChar));
}
clause.IsLogicalUnit = true;
tokenizer.Advance();
return(clause);
case '"':
try
{
var stringValue = tokenizer.ReadQuotedString().ToString();
return(new StringConstantExpression(stringValue));
}
catch (InvalidOperationException ex)
{
return(ParseError(tokenizer, ex.Message));
}
case '0':
if (tokenizer.Match("0x"))
{
string hexNumber = "";
while (Char.IsDigit(tokenizer.NextChar) || (tokenizer.NextChar >= 'A' && tokenizer.NextChar <= 'F') || (tokenizer.NextChar >= 'a' && tokenizer.NextChar <= 'f'))
{
hexNumber += tokenizer.NextChar;
tokenizer.Advance();
}
int hexValue = 0;
Int32.TryParse(hexNumber, System.Globalization.NumberStyles.HexNumber, System.Globalization.CultureInfo.CurrentCulture, out hexValue);
return(new IntegerConstantExpression(hexValue));
}
goto case '1';
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
{
var number = tokenizer.ReadNumber();
uint value;
UInt32.TryParse(number.ToString(), out value);
return(new IntegerConstantExpression((int)value));
}
case '-':
tokenizer.Advance();
if (tokenizer.NextChar >= '0' && tokenizer.NextChar <= '9')
{
if (tokenizer.Match("0x"))
{
string hexNumber = "";
while (Char.IsDigit(tokenizer.NextChar) || (tokenizer.NextChar >= 'A' && tokenizer.NextChar <= 'F') || (tokenizer.NextChar >= 'a' && tokenizer.NextChar <= 'f'))
{
hexNumber += tokenizer.NextChar;
tokenizer.Advance();
}
int hexValue = 0;
Int32.TryParse(hexNumber, System.Globalization.NumberStyles.HexNumber, System.Globalization.CultureInfo.CurrentCulture, out hexValue);
return(new IntegerConstantExpression(-hexValue));
}
var number = tokenizer.ReadNumber();
int value;
Int32.TryParse(number.ToString(), out value);
return(new IntegerConstantExpression(-value));
}
return(ParseError(tokenizer, "Minus without value"));
case '{':
tokenizer.Advance();
return(DictionaryExpression.Parse(tokenizer));
case '[':
tokenizer.Advance();
return(ParseArray(tokenizer));
default:
var line = tokenizer.Line;
var column = tokenizer.Column;
var identifier = tokenizer.ReadIdentifier();
if (identifier.IsEmpty)
{
var error = ParseError(tokenizer, "Unexpected character: " + tokenizer.NextChar);
tokenizer.Advance();
return(error);
}
SkipWhitespace(tokenizer);
if (identifier == "return")
{
clause = ExpressionBase.Parse(tokenizer);
if (clause.Type == ExpressionType.ParseError)
{
return(clause);
}
return(new ReturnExpression(new KeywordExpression(identifier.ToString(), line, column), clause));
}
if (identifier == "function")
{
return(FunctionDefinitionExpression.Parse(tokenizer, line, column));
}
if (identifier == "for")
{
return(ForExpression.Parse(tokenizer, line, column));
}
if (identifier == "if")
{
return(IfExpression.Parse(tokenizer, line, column));
}
if (tokenizer.NextChar == '(')
{
tokenizer.Advance();
var parameters = new List <ExpressionBase>();
ParseParameters(tokenizer, parameters);
var functionCall = new FunctionCallExpression(new VariableExpression(identifier.ToString(), line, column), parameters);
functionCall.EndLine = tokenizer.Line;
functionCall.EndColumn = tokenizer.Column - 1;
return(functionCall);
}
if (tokenizer.NextChar == '[')
{
IndexedVariableExpression parent = null;
do
{
tokenizer.Advance();
var index = ExpressionBase.Parse(tokenizer);
if (index.Type == ExpressionType.ParseError)
{
return(index);
}
SkipWhitespace(tokenizer);
if (tokenizer.NextChar != ']')
{
return(ParseError(tokenizer, "Expecting closing bracket after index"));
}
tokenizer.Advance();
SkipWhitespace(tokenizer);
if (parent != null)
{
parent = new IndexedVariableExpression(parent, index);
}
else
{
parent = new IndexedVariableExpression(new VariableExpression(identifier.ToString(), line, column), index);
}
} while (tokenizer.NextChar == '[');
return(parent);
}
return(new VariableExpression(identifier.ToString(), line, column));
}
}
