public ForLoopNode(VariableIdNode idNode, Dictionary <string, IProperty> symbolTable, Token token)
{
this.idNode = idNode;
this.token = token;
this.indexAccumulator = createIndexAccumulator(idNode, symbolTable, token);
}
/// <summary>
/// Checks the static semantic constraints of an AssignNode.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitAssignNode(AssignNode node)
{
// Check that the id property in this AssignNode is ok.
IProperty property = getVariableProperty(node);
// if the property was voidProperty, return at this point,
// an error has been reported already
if (property == voidProperty)
{
return(voidProperty);
}
VariableIdNode idNode = node.IDNode;
// check that the id variable is declared
checkPropertyDeclared(idNode, property, true);
// check that the id property we should be assigning to is not constant
// at this point of its lifecycle (i.e. not a current block's control variable)
if (property.Constant)
{
analyzer.notifyError(new IllegalAssignmentError(node));
}
// evaluate the type of this property
IProperty evaluated = node.Accept(this.typeChecker).asProperty();
// check the type of the expression in the assign node matches the one in the symbol table
if (!checkPropertyType(property, evaluated.GetTokenType()))
{
analyzer.notifyError(new IllegalTypeError(idNode));
}
return(voidProperty);
}
public AssignNode CreateAssignNode(VariableIdNode idNode, StatementsNode statementsNode, Token t)
{
AssignNode assignNode = new AssignNode(idNode, symbolTable, t);
statementsNode.Statement = assignNode;
return(assignNode);
}
/// <summary>
/// Visits the assign node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitAssignNode(AssignNode node)
{
// assign the idNode's value to the one in the expression node
VariableIdNode idNode = node.IDNode;
IProperty assignValue = node.ExprNode.Accept(this).asProperty();
symbolTable [idNode.ID] = assignValue;
return(voidProperty);
}
private AssignNode createIndexAccumulator(VariableIdNode idNode, Dictionary <string, IProperty> symbolTable, Token token)
{
AssignNode accumulator = new AssignNode(idNode, symbolTable, token);
BinOpNode accumulationOperation = new BinOpNode(token);
accumulationOperation.Operation = TokenType.BINARY_OP_ADD;
accumulationOperation.AddExpression(idNode);
accumulationOperation.AddExpression(new IntValueNode(1, token));
accumulator.ExprNode = accumulationOperation;
return(accumulator);
}
/// <summary>
/// Parses an assign statement.
/// </summary>
/// <returns>The next token.</returns>
/// <param name="token">Token.</param>
/// <param name="statementsNode">Statements node.</param>
private Token ParseVariableAssign(Token token, StatementsNode statementsNode)
{
try {
VariableIdNode idNode = nodeBuilder.CreateIdNode();
// parse the target id
Token next = ParseVarId(token, idNode);
match(next, TokenType.ASSIGN);
AssignNode assignNode = nodeBuilder.CreateAssignNode(idNode, statementsNode, token);
// parses the expression of the assignment
return(ParseExpression(scanner.getNextToken(next), assignNode));
} catch (UnexpectedTokenException ex) {
return(FastForwardToStatementEnd(ex));
}
}
/// <summary>
/// Visits the IO read node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitIOReadNode(IOReadNode node)
{
// read an input
string input = reader.readLine();
// select the first word of the input
input = input.Split(new[] { ' ', '\t', '\n' })[0];
// set the input to the ioreadnode's assignment
AssignNode assignNode = node.AssignNode;
setAssignValue(input, assignNode);
// execute the assign node
assignNode.Accept(this);
return(voidProperty);
}
/// <summary>
/// Parses an assignment during a declaration statement into an AssignNode.
/// </summary>
/// <returns>The next token.</returns>
/// <param name="token">Token.</param>
/// <param name="assignNode">An AssignNode.</param>
private Token ParseAssign(Token token, AssignNode assignNode)
{
switch (token.Type)
{
case TokenType.ASSIGN:
// if assignment during a declaration was made, parse the expression to the AssignNode
assignNode.Token = token;
Token next = scanner.getNextToken(token);
return(ParseExpression(next, assignNode));
case TokenType.END_STATEMENT:
// otherwise, set a default assignment
setDefaultAssignment(assignNode);
return(token);
default:
throw new UnexpectedTokenException(token, TokenType.UNDEFINED, ParserConstants.EXPECTATION_SET_ASSIGN);
}
}
/// <summary>
/// Sets a default assignment to an AssignNode.
/// </summary>
/// <param name="assignNode">An AssignNode.</param>
private void setDefaultAssignment(AssignNode assignNode)
{
TokenType idType = assignNode.IDNode.EvaluationType;
switch (idType)
{
case TokenType.STR_VAL:
nodeBuilder.CreateDefaultStringValueNode(assignNode.Token, assignNode);
break;
case TokenType.INT_VAL:
nodeBuilder.CreateDefaultIntValueNode(assignNode.Token, assignNode);
break;
case TokenType.BOOL_VAL:
nodeBuilder.CreateDefaultBoolValueNode(assignNode.Token, assignNode);
break;
default:
throw new UnexpectedTokenException(assignNode.IDNode.Token, TokenType.UNDEFINED, ParserConstants.EXPECTATION_SET_ID_VAL);
}
}
/// <summary>
/// Sets the value of a variable read from user.
/// </summary>
/// <param name="input">Input.</param>
/// <param name="assignNode">Assign node.</param>
private void setAssignValue(string input, AssignNode assignNode)
{
TokenType expectedType = assignNode.IDNode.EvaluationType;
// based on the variable's type, we try to parse the user's input
switch (expectedType)
{
case TokenType.INT_VAL:
// if its supposed to be an integer but its not, throw a runtime exception
if (!StringUtils.isInteger(input))
{
throw new RuntimeException(ErrorConstants.NOT_AN_INTEGER_MESSAGE, assignNode.Token);
}
assignNode.AddExpression(new IntValueNode(StringUtils.parseToInt(input)));
break;
case TokenType.STR_VAL:
assignNode.AddExpression(new StringValueNode(input));
break;
default:
throw new RuntimeException(ErrorConstants.RUNTIME_ERROR_MESSAGE, assignNode.Token);
}
}
/// <summary>
/// Visits the assign node.
/// </summary>
/// <returns>a VoidProperty.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitAssignNode(AssignNode node)
{
// nothing to evaluate here, it's done from the ExecutionVisitor
return(voidProperty);
}
public IOReadNode(VariableIdNode idNode, Dictionary <string, IProperty> symbolTable, Token t)
{
this.idNode = idNode;
this.assignNode = new AssignNode(this.idNode, symbolTable, t);
this.token = t;
}
/// <summary>
/// Visits the assign node.
/// </summary>
/// <returns>An ISemanticCheckValue.</returns>
/// <param name="node">Node.</param>
public ISemanticCheckValue VisitAssignNode(AssignNode node)
{
// return the evaluation of the node's expression
return(getEvaluation(node.ExprNode));
}
