override public void Visit(AST_variable_declaration variable_declaration)
{
if (variable_declaration.Type != null)
{
variable_declaration.Type.Accept(this);
}
string name = variable_declaration.Identifier.Name;
if (variables.ContainsKey(name))
{
Error("Variable '" + name + "' has already been declared.", variable_declaration.Identifier);
}
else
{
AST_expression expr = variable_declaration.Expression;
if (expr != null)
{
expr.Accept(this);
if (expr.DataType != variable_declaration.Type.Kind)
{
Error("Variable and initial value must be same type.", variable_declaration.Expression);
}
}
variables.Add(name, variable_declaration);
}
variable_declaration.Identifier.Accept(this);
}
override public void Visit(AST_for_statement for_statement)
{
for_statement.Identifier.Accept(this);
if (for_statement.From != null)
{
for_statement.From.Accept(this);
}
if (for_statement.To != null)
{
for_statement.To.Accept(this);
}
string name = for_statement.Identifier.Name;
bool variableReserved = false;
AST_variable_declaration declaration = variables.GetValueOrDefault(name);
if (declaration != null)
{
if (variables.GetValueOrDefault(name).Type.Kind == int_type)
{
// Make sure the variable is not already a loop variable in an outer loop
if (loopVariables.ContainsKey(for_statement.Identifier.Name))
{
Error("'" + name + "' is already a loop variable.", for_statement.Identifier);
}
else
{
loopVariables.Add(name, false);
variableReserved = true;
}
}
else
{
Error("Loop variable must be of int type.", for_statement.Identifier);
}
}
if (for_statement.From != null && for_statement.From.DataType != int_type)
{
Error("Lower boundary must be of int type.", for_statement.From);
}
if (for_statement.To != null && for_statement.To.DataType != int_type)
{
Error("Upper boundary must be of int type.", for_statement.To);
}
if (for_statement.StatementList != null)
{
for_statement.StatementList.Accept(this);
}
if (variableReserved)
{
loopVariables.Remove(name);
}
}
public virtual void Visit(AST_variable_declaration variable_declaration)
{
IncrementDepth();
variable_declaration.Identifier.Accept(this);
if (variable_declaration.Type != null)
{
variable_declaration.Type.Accept(this);
}
if (variable_declaration.Expression != null)
{
variable_declaration.Expression.Accept(this);
}
DecrementDepth();
}
private AST_variable_declaration Parse_variable_declaration()
{
IncrementDepth();
AST_variable_declaration variable_declaration;
AST_identifier name;
AST_type type = null;
AST_expression expression = null;
Match(var_Keyword);
name = Parse_identifier(Colon | Semicolon);
if (!Match(Colon))
{
Error("':' expected.", lastReadToken);
SkipUntilFollow(Semicolon);
}
else
{
type = Parse_type(Assignment | Semicolon);
switch (LookAheadToken().Kind)
{
case Assignment:
Match(Assignment);
expression = Parse_expression(Semicolon);
break;
case Semicolon:
break;
default:
Error("':=' or ';' expected.", LookAheadToken());
SkipUntilFollow(Semicolon);
break;
}
}
variable_declaration = new AST_variable_declaration(name, type, expression);
DecrementDepth();
return(variable_declaration);
}
override public void Visit(AST_variable_declaration variable_declaration)
{
Variable variable;
if (variable_declaration.Expression != null)
{
variable_declaration.Expression.Accept(this);
variable = value.Copy();
}
else
{
variable = new Variable(variable_declaration.Type.Kind);
}
string name = variable_declaration.Identifier.Name;
if (variables.ContainsKey(name))
{
variables.Remove(name);
}
variables.Add(name, variable);
}
override public void Visit(AST_variable_declaration variable_declaration)
{
variable_declaration.Accept(evaluateVisitor);
}