IBoundExpr IUnboundExprVisitor<IBoundExpr>.Visit(BlockExpr block)
{
// create an inner scope
if (block.HasScope) Scope.Push();
var exprs = new List<IBoundExpr>();
var index = 0;
foreach (IUnboundExpr expr in block.Exprs)
{
var bound = expr.Accept(this);
// all but last expression must be void
if (index < block.Exprs.Count - 1)
{
if (bound.Type != Decl.Unit) throw new CompileException(expr.Position, "All expressions in a block except the last must be of type Unit. " + block.ToString());
}
index++;
exprs.Add(bound);
}
if (block.HasScope) Scope.Pop();
return new BoundBlockExpr(exprs);
}
private IUnboundExpr SyntaxExpr()
{
Position position;
if (ConsumeIf(TokenType.LeftCurly, out position))
{
// ignore a leading line
ConsumeIf(TokenType.Line);
var expressions = new List <IUnboundExpr>();
while (true)
{
expressions.Add(Expression());
if (ConsumeIf(TokenType.RightCurly))
{
break;
}
Consume(TokenType.Line);
if (ConsumeIf(TokenType.RightCurly))
{
break;
}
}
IUnboundExpr expr;
if (expressions.Count > 1)
{
expr = new BlockExpr(expressions);
}
else
{
expr = expressions[0];
}
return(new SyntaxExpr(position, expr));
}
else
{
return(DefineExpr());
}
}
public virtual IUnboundExpr Transform(BlockExpr expr)
{
return(expr);
}
IUnboundExpr IUnboundExprVisitor <IUnboundExpr> .Visit(BlockExpr expr)
{
return(Call("BlockExpr", Array(expr.Exprs.Accept(this))));
}