internal override IEnumerable <Instruction> Compile()
{
IEnumerable <Instruction> compiledCondition = Condition.Compile();
Instruction[] compiledPathTrue = PathTrue.Compile().ToArray();
Instruction[] compiledElseStatement = ElseStatement?.Compile().ToArray() ?? new Instruction[0];
List <Instruction> instructions = new List <Instruction>();
instructions.AddRange(compiledCondition);
if (RedwoodType.GetForCSharpType(typeof(bool)) != Condition.GetKnownType())
{
throw new NotImplementedException();
}
// The index of the jump instruction relative to the the else is -1
// (ie. right before the start). When we factor in the jump, we need
// to skip 2 additional instructions
instructions.Add(new ConditionalJumpInstruction(compiledElseStatement.Length + 2));
instructions.AddRange(compiledElseStatement);
instructions.Add(new JumpInstruction(compiledPathTrue.Length + 1));
instructions.AddRange(compiledPathTrue);
return(instructions);
}
internal override IEnumerable <NameExpression> Walk()
{
List <NameExpression> freeVars = new List <NameExpression>();
freeVars.AddRange(Condition.Walk());
freeVars.AddRange(PathTrue.Walk());
if (ElseStatement != null)
{
freeVars.AddRange(ElseStatement.Walk());
}
return(freeVars);
}
internal override void Bind(Binder binder)
{
Condition.Bind(binder);
binder.Bookmark();
PathTrue.Bind(binder);
binder.Checkout();
if (ElseStatement != null)
{
binder.Bookmark();
ElseStatement.Bind(binder);
binder.Checkout();
}
}
