LNode GetOutputAsLNode()
{
WList <LNode> finalOutput = _handler.ToWList();
for (int end = _output.Count - 1; end >= 0; end--)
{
var tmp_10 = _output[end];
Mode mode = tmp_10.Item1;
LNode code = tmp_10.Item2;
if (mode == Mode.Condition)
{
// Merge adjacent conditions into the same if-statement
int start = end;
for (; start > 0 && _output[start - 1].A == mode; start--)
{
}
LNode cond = _output[start].B;
for (int i = start + 1; i <= end; i++)
{
cond = LNode.Call(CodeSymbols.And, LNode.List(cond, _output[i].B)).SetStyle(NodeStyle.Operator);
}
end = start;
finalOutput = new WList <LNode> {
LNode.Call(CodeSymbols.If, LNode.List(cond, finalOutput.ToLNodeList().AsLNode(S.Braces)))
};
}
else
{
finalOutput.Insert(0, code);
}
}
return(finalOutput.ToLNodeList().AsLNode(S.Braces));
}
public void Generate(Rule rule)
{
CGH.BeginRule(rule);
_currentRule = rule;
_target = new WList <LNode>();
_laVarsNeeded = 0;
_separatedMatchCounter = _stopLabelCounter = 0;
_recognizerMode = rule.IsRecognizer;
_labelsInUse.Clear();
Visit(rule.Pred);
if (_laVarsNeeded != 0)
{
LNode laVars = F.Call(S.Var, CGH.LAType());
for (int i = 0; _laVarsNeeded != 0; i++, _laVarsNeeded >>= 1)
{
if ((_laVarsNeeded & 1) != 0)
{
laVars = laVars.PlusArg(F.Id("la" + i.ToString()));
}
}
_target.Insert(0, laVars);
}
LNode method;
if (rule.TryWrapperName != null)
{
Debug.Assert(rule.IsRecognizer);
method = F.OnNewLine(CGH.CreateTryWrapperForRecognizer(rule));
_classBody.SpliceAdd(method, S.Splice);
}
method = CGH.CreateRuleMethod(rule, _target.ToLNodeList());
if (!rule.IsRecognizer)
{
method = F.OnNewLine(method);
}
_classBody.SpliceAdd(method, S.Splice);
}
public static LNode unroll(LNode var, LNodeList cases, LNode body, IMessageSink sink)
{
// Maps identifiers => replacements. The integer counts how many times replacement occurred.
var replacements = InternalList <Triplet <Symbol, LNode, int> > .Empty;
if (var.IsId && !var.HasPAttrs())
{
replacements.Add(Triplet.Create(var.Name, (LNode)LNode.Missing, 0));
}
else
{
var vars = var.Args;
if ((var.Calls(S.Tuple) || var.Calls(S.Braces)) && vars.All(a => a.IsId && !a.HasPAttrs()))
{
replacements = new Triplet <Symbol, LNode, int> [vars.Count].AsInternalList();
for (int i = 0; i < vars.Count; i++)
{
replacements.InternalArray[i].A = vars[i].Name;
// Check for duplicate names
for (int j = 0; j < i; j++)
{
if (replacements[i].A == replacements[j].A && replacements[i].A.Name != "_")
{
sink.Error(vars[i], "Duplicate name in the left-hand tuple"); // non-fatal
}
}
}
}
else
{
return(Reject(sink, var, "The left-hand side of 'in' should be a simple identifier or a tuple of simple identifiers."));
}
}
UnrollCtx ctx = new UnrollCtx {
Replacements = replacements
};
WList <LNode> output = new WList <LNode>();
int iteration = 0;
foreach (LNode replacement in cases)
{
iteration++;
bool tuple = replacement.Calls(S.Tuple) || replacement.Calls(S.Braces);
int count = tuple ? replacement.ArgCount : 1;
if (replacements.Count != count)
{
sink.Error(replacement, "iteration {0}: Expected {1} replacement items, got {2}", iteration, replacements.Count, count);
if (count < replacements.Count)
{
continue; // too few
}
}
for (int i = 0; i < replacements.Count; i++)
{
replacements.InternalArray[i].B = tuple ? replacement.Args[i] : replacement;
}
if (body.Calls(S.Braces))
{
foreach (LNode stmt in body.Args)
{
output.Add(ctx.Replace(stmt).Value);
}
}
else
{
output.Add(ctx.Replace(body).Value);
}
}
foreach (var r in replacements)
{
if (r.C == 0 && !r.A.Name.StartsWith("_"))
{
sink.Write(Severity.Warning, var, "Replacement variable '{0}' was never used", r.A);
}
}
return(body.With(S.Splice, output.ToLNodeList()));
}
public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
LNodeList contents;
if (node.Args.Count == 2 && (input = node.Args[0]) != null && node.Args[1].Calls(CodeSymbols.Braces))
{
contents = node.Args[1].Args;
var outputs = new WList <LNode>();
input = MaybeAddTempVarDecl(context, input, outputs);
// Process the braced block, one case at a time
int next_i = 0;
for (int case_i = 0; case_i < contents.Count; case_i = next_i)
{
var @case = contents[case_i];
if (!IsCaseLabel(@case) // `case ...:` or `default:`
)
{
return(Reject(context, contents[0], "In 'match': expected 'case' statement"));
}
// Find the end of the current case/default block
for (next_i = case_i + 1; next_i < contents.Count; next_i++)
{
var stmt = contents[next_i];
if (IsCaseLabel(stmt))
{
break;
}
if (stmt.Calls(S.Break, 0))
{
next_i++;
break;
}
}
// handler: the list of statements underneath `case`
var handler = new LNodeList(contents.Slice(case_i + 1, next_i - (case_i + 1)));
if (@case.Calls(S.Case) && @case.Args.Count > 0)
{
var codeGen = new CodeGeneratorForMatchCase(context, input, handler);
foreach (var pattern in @case.Args)
{
outputs.Add(codeGen.GenCodeForPattern(pattern));
}
}
else // default:
// Note: the extra {braces} around the handler are rarely
// needed. They are added just in case the handler declares a
// variable and a different handler declares another variable
// by the same name, which is illegal unless we add braces.
{
outputs.Add(LNode.Call(CodeSymbols.Braces, LNode.List(handler)).SetStyle(NodeStyle.StatementBlock));
if (next_i < contents.Count)
{
context.Sink.Error(@contents[next_i], "The default branch must be the final branch in a 'match' statement.");
}
}
}
return(LNode.Call(CodeSymbols.DoWhile, LNode.List(outputs.ToLNodeList().AsLNode(S.Braces), LNode.Literal(false))));
}
}
return(null);
}
