public static LNode use_symbols(LNode input, IMacroContext context)
{
var args_body = context.GetArgsAndBody(true);
// Decode options (TODO: invent a simpler approach)
string prefix = "sy_";
var inherited = new HashSet <Symbol>();
foreach (var pair in MacroContext.GetOptions(args_body.A))
{
if (pair.Key.Name == "prefix" && pair.Value.IsId)
{
prefix = pair.Value.Name.Name;
}
else if (pair.Key.Name == "inherit" && pair.Value.Value is Symbol)
{
inherited.Add((Symbol)pair.Value.Value);
}
else if (pair.Key.Name == "inherit" && (pair.Value.Calls(S.Braces) || pair.Value.Calls(S.Tuple)) && pair.Value.Args.All(n => n.Value is Symbol))
{
foreach (var arg in pair.Value.Args)
{
inherited.Add((Symbol)arg.Value);
}
}
else
{
context.Sink.Write(Severity.Warning, pair.Value, "Unrecognized parameter. Expected prefix:id or inherit:{@@A; @@B; ...})");
}
}
// Replace all symbols while collecting a list of them
var symbols = new Dictionary <Symbol, LNode>();
RVList <LNode> output = args_body.B.SmartSelect(stmt => stmt.ReplaceRecursive(n => {
var sym = n.Value as Symbol;
if (n.IsLiteral && sym != null)
{
return(symbols[sym] = LNode.Id(prefix + Ecs.EcsNodePrinter.SanitizeIdentifier(sym.Name)));
}
return(null);
}));
// Return updated code with variable declaration at the top for all non-inherit symbols used.
var _Symbol = F.Id("Symbol");
var vars = (from sym in symbols
where !inherited.Contains(sym.Key)
select F.Call(S.Assign, sym.Value,
F.Call(S.Cast, F.Literal(sym.Key.Name), _Symbol))).ToList();
if (vars.Count > 0)
{
output.Insert(0, F.Call(S.Var, Range.Single(_Symbol).Concat(vars))
.WithAttrs(input.Attrs.Add(F.Id(S.Static)).Add(F.Id(S.Readonly))));
}
return(F.Call(S.Splice, output));
}
public static RVList <LNode> WithSpliced(this RVList <LNode> list, int index, LNode node, Symbol listName)
{
if (node.Calls(listName))
{
return(list.InsertRange(index, node.Args));
}
else
{
return(list.Insert(index, node));
}
}