/// <summary>
/// Visit LetStatement
/// </summary>
/// <param name="statement">LetStatement to check</param>
public override void Visit(LetStatement statement)
{
foreach (Assignment assignment in statement.GetAssignments())
{
//Go level deeper in SymbolTable, to check using variables in other assignments
CreateChildSymbolTable();
//Visit Assignment
assignment.AcceptVisitor(this);
}
//Visit statements
foreach(Statement stmt in statement.GetStatements())
{
stmt.AcceptVisitor(this);
}
//Go back to level of statement in SymbolTable
foreach (Assignment assignment in statement.GetAssignments())
{
MoveToParentSymbolTable();
}
}
/// <summary>
/// Parser for LetStatement
/// </summary>
/// <returns>Parsed LetStatement</returns>
public LetStatement ParseLetStatement()
{
LetStatement letStatement = new LetStatement();
//Skip let token
NextToken("let", "let assignment+ in statement* end", "let");
//Parse arguments
while(TokenStream.HasNext())
{
if(TokenStream.Peek(1).GetValue().ToString() == "in")
{
break; //no more assignments left
}
letStatement.AddAssignment(ParseAssignment());
}
if (letStatement.GetAssignments().Count == 0)
{ //No assignments is not allowed
throw new UnexpectedToken("LetStatement doesn't contain assignments.", "Expected at least one assignment ", CurrentToken.GetLine());
//throw new UnexpectedToken();
}
//Skip in token
NextToken("in", "let assignment+ in statement* end", "in");
//Parse statements
while (TokenStream.HasNext())
{
if (TokenStream.Peek(1).GetValue().ToString() == "end")
{ //No more statements left
break;
}
letStatement.AddStatement(ParseStatement());
}
//Skip end token
NextToken("end", "let assignment+ in statement* end", "end");
return letStatement;
}