/// <summary>
/// Interpret LetStatement
/// </summary>
/// <param name="statement">LetStatement to interpret</param>
public override void Visit(LetStatement statement)
{
//Create SymbolTable's for each assignment to let referencing work properly
foreach (Assignment asgn in statement.GetAssignments())
{
SymbolTable = new SymbolTable(SymbolTable);
asgn.AcceptVisitor(this);
}
//If no root element, create one
if (statement.GetStatements().Count > 1 && Root == null)
{
XHTMLElement newRoot = new XHTMLElement("html", null, true);
Root = newRoot;
Current = Root;
}
//Interpret statements
int depth = this.Depth;
foreach (Statement stmt in statement.GetStatements())
{
stmt.AcceptVisitor(this);
BackToParentXHTMLElement(depth);
}
//Go back to scope outside let statement
foreach (Assignment asgn in statement.GetAssignments())
{
SymbolTable = SymbolTable.GetParentSymbolTable();
}
}
/// <summary>
/// Interpret EachStatement
/// </summary>
/// <param name="statement">EachStatement to interpret</param>
public override void Visit(EachStatement statement)
{
//If no root element, create one
if (Root == null)
{
XHTMLElement newRoot = new XHTMLElement("html", null, true);
Root = newRoot;
Current = Root;
}
Expression expr = statement.GetExpression();
//Different looping with different expression types
if (expr is ListExpression)
{ //Iterate through list
ListExpression listExpression = (ListExpression)expr;
//Iterate through list with expression
XHTMLElement temp = Current;
foreach (Expression currentExpr in listExpression.GetExpressions())
{
Current = temp;
//New scope
SymbolTable = new SymbolTable(SymbolTable);
//Define variable and interpret statement with this scope
SymbolTable.AddVariableDefinition(statement.GetIdentifier(), currentExpr);
statement.GetStatement().AcceptVisitor(this);
//Return to parent scope
SymbolTable = SymbolTable.GetParentSymbolTable();
}
}
else if (expr is FieldExpression)
{ //Get expression in referenced record
Expression expression = GetExpression((FieldExpression)expr);
//Visit each for expression
EachStatement eachStatement = new EachStatement();
eachStatement.SetExpression(expression);
eachStatement.SetStatement(statement.GetStatement());
eachStatement.SetIdentifier(statement.GetIdentifier());
Visit(eachStatement);
}
else if (expr is VarExpression)
{ //Get expression of variable
Expression expression = SymbolTable.GetVariableDefinition(((VarExpression)expr).GetVariableIdentifier());
//Visit each for expression
EachStatement eachStatement = new EachStatement();
eachStatement.SetExpression(expression);
eachStatement.SetStatement(statement.GetStatement());
eachStatement.SetIdentifier(statement.GetIdentifier());
Visit(eachStatement);
}
}
/// <summary>
/// Interpret VarExpression
/// </summary>
/// <param name="expression">VarExpression to interpret</param>
public override void Visit(VarExpression expression)
{
//Check if variable does exist
String varName = expression.GetVariableIdentifier();
Expression check = SymbolTable.GetVariableDefinition(varName);
//If reference has been made to parent variable with same name, take parent reference
if (check == expression && SymbolTable.GetParentSymbolTable() != null)
{
check = SymbolTable.GetParentSymbolTable().GetVariableDefinition(varName);
}
if (check != null)
{ //Visit variable to retrieve current value
check.AcceptVisitor(this);
}
else
{
TextValue = "undef";
}
}