public static LNode UnpackTuple(LNode node, IMacroContext context)
{
var a = node.Args;
if (a.Count == 2 && a[0].CallsMin(S.Tuple, 1))
{
var output = new WList <LNode>();
var tuple = a[0].Args;
var rhs = a[1];
// Avoid evaluating rhs more than once, if it doesn't look like a simple variable
rhs = LeMP.ecs.StandardMacros.MaybeAddTempVarDecl(context, rhs, output);
for (int i = 0; i < tuple.Count; i++)
{
var itemi = F.Dot(rhs, F.Id(GSymbol.Get("Item" + (i + 1))));
if (tuple[i].Calls(S.Var, 2))
{
output.Add(F.Var(tuple[i].Args[0], tuple[i].Args[1], itemi));
}
else
{
output.Add(F.Call(S.Assign, tuple[i], itemi));
}
}
return(F.Call(S.Splice, output.ToVList()));
}
return(null);
}
private WList <LNode> GenerateExtraMatchingCode(Pair <LNode, string>[] matchingCode, int separateCount, ref Symbol loopType)
{
var extraMatching = new WList <LNode>();
if (separateCount != 0)
{
for (int i = 0; i < matchingCode.Length; i++)
{
if (matchingCode[i].B != null) // split out this case
{
var label = F.Id(matchingCode[i].B);
// break/continue; matchN: matchingCode[i].A;
if (extraMatching.Count > 0)
{
extraMatching.Add(GetContinueStmt(loopType));
}
extraMatching.Add(F.Call(S.Label, label));
extraMatching.Add(matchingCode[i].A);
//skipCount++;
// put @@{ goto matchN; } in prediction tree
matchingCode[i].A = F.Call(S.Goto, label);
}
}
}
return(extraMatching);
}
public static LNode unroll(LNode var, LNode cases, LNode body, IMessageSink sink)
{
if (!cases.Calls(S.Tuple) && !cases.Calls(S.Braces))
return Reject(sink, cases, "unroll: the right-hand side of 'in' should be a tuple");
// 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(Pair.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.Write(Severity.Error, vars[i], "unroll: duplicate name in the left-hand tuple"); // non-fatal
}
} else
return Reject(sink, cases, "unroll: 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.Args)
{
iteration++;
bool tuple = replacement.Calls(S.Tuple) || replacement.Calls(S.Braces);
int count = tuple ? replacement.ArgCount : 1;
if (replacements.Count != count)
{
sink.Write(Severity.Error, replacement, "unroll, 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.ToVList());
}
[LexicalMacro("match (var) { case ...: ... }; // In LES, use a => b instead of case a: b", "Attempts to match and deconstruct an object against a \"pattern\", such as a tuple or an algebraic data type. Example:\n" + "match (obj) { \n" + " case is Shape(ShapeType.Circle, $size, Location: $p is Point<int>($x, $y)): \n" + " Circle(size, x, y); \n" + "}\n\n" + "This is translated to the following C# code: \n" + "do { \n" + " Point<int> p; \n" + " Shape tmp1; \n" + " if (obj is Shape) { \n" + " var tmp1 = (Shape)obj; \n" + " if (tmp1.Item1 == ShapeType.Circle) { \n" + " var size = tmp1.Item2; \n" + " var tmp2 = tmp1.Location; \n" + " if (tmp2 is Point<int>) { \n" + " var p = (Point<int>)tmp2; \n" + " var x = p.Item1; \n" + " var y = p.Item2; \n" + " Circle(size, x, y); \n" + " break; \n" + " } \n" + " }\n" + " }\n" + "} while(false); \n" + "`break` is not expected at the end of each handler (`case` code block), but it can " + "be used to exit early from a `case`. You can associate multiple patterns with the same " + "handler using `case pattern1, pattern2:` in EC#, but please note that (due to a " + "limitation of plain C#) this causes code duplication since the handler will be repeated " + "for each pattern.")] public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
VList <LNode> 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(input, outputs);
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))
{
return(Reject(context, contents[0], "In 'match': expected 'case' statement"));
}
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;
}
}
var handler = new VList <LNode>(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
{
outputs.Add(LNode.Call(CodeSymbols.Braces, LNode.List(handler)).SetStyle(NodeStyle.Statement));
if (next_i < contents.Count)
{
context.Write(Severity.Error, contents[next_i], "The default branch must be the final branch in a 'match' statement.");
}
}
}
return(LNode.Call(CodeSymbols.DoWhile, LNode.List(outputs.ToVList().AsLNode(S.Braces), LNode.Literal(false))));
}
}
return(null);
}
public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
VList <LNode> 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);
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))
{
return(Reject(context, contents[0], "In 'match': expected 'case' statement"));
}
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;
}
}
var handler = new VList <LNode>(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
{
outputs.Add(LNode.Call(CodeSymbols.Braces, LNode.List(handler)).SetStyle(NodeStyle.Statement));
if (next_i < contents.Count)
{
context.Write(Severity.Error, contents[next_i], "The default branch must be the final branch in a 'match' statement.");
}
}
}
return(LNode.Call(CodeSymbols.DoWhile, LNode.List(outputs.ToVList().AsLNode(S.Braces), LNode.Literal(false))));
}
}
return(null);
}
private void AddSwitchHandler(LNode branch, WList <LNode> stmts)
{
stmts.SpliceAdd(branch, S.Splice);
if (EndMayBeReachable(branch))
{
stmts.Add(F.Call(S.Break));
}
}
private void AddUserAction(VList <LNode> actions)
{
int i = _target.Count;
_target.AddRange(actions);
if (actions.Any(stmt => stmt.Range.StartIndex > 0))
{
if (LLPG.AddCsLineDirectives)
{
// Remove folder name. This only makes sense if the output
// file and input file are in the same folder; sadly we have
// no access to the output file name, but as of 2015-05 it's
// always true that the output file will be in the same folder.
string filename = System.IO.Path.GetFileName(_target[i].Range.Source.FileName);
var newline = F.Id(S.TriviaNewline);
int line = 0;
for (; i < _target.Count; i++, line++)
{
var r = _target[i].Range;
if (line != r.Start.Line)
{
line = r.Start.Line;
if (line <= 0) // sometimes occurs for generated `return result` statement
{
_target.Insert(i++, F.Trivia(S.CsPPRawText, "#line default"));
}
else
{
_target.Insert(i++, F.Trivia(S.CsPPRawText, "#line " + line + " " + Ecs.EcsNodePrinter.PrintString(filename, '"')));
}
}
}
if (line > 1)
{
_target.Add(F.Trivia(S.CsPPRawText, "#line default"));
}
}
else
{
_target[i] = _target[i].PlusAttr(F.Trivia(S.TriviaSLComment,
string.Format(" line {0}", _target[i].Range.Start.Line)));
}
}
}
// Used to avoid evaluating `value` more than once by creating a
// declaration in `output` of a temporary variable to hold the value.
// If `value` looks simple (according to LooksLikeSimpleValue), this
// fn returns value and leaves output unchanged.
protected static LNode MaybeAddTempVarDecl(IMacroContext ctx, LNode value, WList<LNode> output)
{
if (!LooksLikeSimpleValue(value)) {
LNode tmpId;
output.Add(TempVarDecl(ctx, value, out tmpId));
return tmpId;
}
return value;
}
// Used to avoid evaluating `value` more than once by creating a
// declaration in `output` of a temporary variable to hold the value.
// If `value` looks simple (according to LooksLikeSimpleValue), this
// fn returns value and leaves output unchanged.
protected static LNode MaybeAddTempVarDecl(LNode value, WList <LNode> output)
{
if (!LooksLikeSimpleValue(value))
{
LNode tmpId;
output.Add(TempVarDecl(value, out tmpId));
return(tmpId);
}
return(value);
}
// Used to avoid evaluating `value` more than once by creating a
// declaration in `output` of a temporary variable to hold the value.
// If `value` looks simple (according to LooksLikeSimpleValue), this
// fn returns value and leaves output unchanged.
protected internal static LNode MaybeAddTempVarDecl(IMacroContext ctx, LNode value, WList <LNode> output)
{
if (!LooksLikeSimpleValue(value))
{
LNode tmpId;
output.Add(TempVarDecl(ctx, value, out tmpId));
return(tmpId);
}
return(value);
}
public static void SpliceAdd(this WList <LNode> list, LNode node, Symbol listName = null)
{
if (node.Calls(listName ?? CodeSymbols.Splice))
{
list.AddRange(node.Args);
}
else
{
list.Add(node);
}
}
private void AddUserAction(LNode action)
{
int i = _target.Count;
_target.SpliceAdd(action, S.Splice);
if (action.Range.StartIndex > 0 && _target.Count > i)
{
if (LLPG.AddCsLineDirectives)
{
// Remove folder name. This only makes sense if the output
// file and input file are in the same folder; sadly we have
// no access to the output file name, but as of 2015-05 it's
// always true that the output file will be in the same folder.
string filename = System.IO.Path.GetFileName(_target[i].Range.Source.FileName);
int line = 0;
for (; i < _target.Count; i++, line++)
{
var r = _target[i].Range;
if (line != r.Start.Line)
{
line = r.Start.Line;
_target[i] = _target[i].PlusAttr(F.Trivia(S.TriviaRawTextBefore,
string.Format("#line {0} {1}\n", line, Ecs.EcsNodePrinter.PrintString(filename, '"'))));
}
}
_target.Add(F.Trivia(S.RawText, "#line default"));
}
else
{
_target[i] = _target[i].PlusAttr(F.Trivia(S.TriviaSLCommentBefore,
string.Format(" line {0}", _target[i].Range.Start.Line)));
}
}
}
[LexicalMacro("match (var) { case ...: ... }; // In LES, use a => b instead of case a: b", "Attempts to match and deconstruct an object against a \"pattern\", such as a tuple or an algebraic data type. Example:\n" + "match (obj) { \n" + " case is Shape(ShapeType.Circle, $size, Location: $p is Point<int>($x, $y)): \n" + " Circle(size, x, y); \n" + "}\n\n" + "This is translated to the following C# code: \n" + "do { \n" + " Point<int> p; \n" + " Shape tmp1; \n" + " if (obj is Shape) { \n" + " var tmp1 = (Shape)obj; \n" + " if (tmp1.Item1 == ShapeType.Circle) { \n" + " var size = tmp1.Item2; \n" + " var tmp2 = tmp1.Location; \n" + " if (tmp2 is Point<int>) { \n" + " var p = (Point<int>)tmp2; \n" + " var x = p.Item1; \n" + " var y = p.Item2; \n" + " Circle(size, x, y); \n" + " break; \n" + " } \n" + " }\n" + " }\n" + "} while(false); \n" + "`break` is not expected at the end of each handler (`case` code block), but it can " + "be used to exit early from a `case`. You can associate multiple patterns with the same " + "handler using `case pattern1, pattern2:` in EC#, but please note that (due to a " + "limitation of plain C#) this causes code duplication since the handler will be repeated " + "for each pattern.")] public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
VList<LNode> 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(input, outputs);
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))
return Reject(context, contents[0], "In 'match': expected 'case' statement");
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;
}
}
var handler = new VList<LNode>(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 {
outputs.Add(LNode.Call(CodeSymbols.Braces, LNode.List(handler)).SetStyle(NodeStyle.Statement));
if (next_i < contents.Count)
context.Write(Severity.Error, contents[next_i], "The default branch must be the final branch in a 'match' statement.");
}
}
return LNode.Call(CodeSymbols.DoWhile, LNode.List(outputs.ToVList().AsLNode(S.Braces), LNode.Literal(false)));
}
}
return null;
}
protected virtual Symbol GenerateSetDecl(IPGTerminalSet set)
{
Symbol setName;
if (_setDeclNames.TryGetValue(set, out setName))
{
return(setName);
}
setName = GenerateSetName(_currentRule);
_classBody.Add(GenerateSetDecl(set, setName));
return(_setDeclNames[set] = setName);
}
public virtual LNode GenerateSwitch(IPGTerminalSet[] branchSets, LNode[] branchCode, MSet <int> casesToInclude, LNode defaultBranch, LNode laVar)
{
Debug.Assert(branchSets.Length == branchCode.Length);
Debug.Assert(casesToInclude.Count <= branchCode.Length);
WList <LNode> stmts = new WList <LNode>();
for (int i = 0; i < branchCode.Length; i++)
{
if (casesToInclude.Contains(i))
{
int index = -1;
foreach (LNode value in GetCases(branchSets[i]))
{
var label = F.Call(S.Case, value);
if (++index > 0 && (index % 4) != 0) // write 4 cases per line
{
label = label.PlusAttr(F.Id(S.TriviaAppendStatement));
}
stmts.Add(label);
if (stmts.Count > 65535) // sanity check
{
throw new InvalidOperationException("switch is too large to generate");
}
}
AddSwitchHandler(branchCode[i], stmts);
}
}
if (!defaultBranch.IsIdNamed(GSymbol.Empty))
{
stmts.Add(F.Call(S.Label, F.Id(S.Default)));
AddSwitchHandler(defaultBranch, stmts);
}
return(F.Call(S.Switch, (LNode)laVar, F.Braces(stmts.ToVList())));
}
public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
VList<LNode> 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);
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))
return Reject(context, contents[0], "In 'match': expected 'case' statement");
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;
}
}
var handler = new VList<LNode>(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.Statement));
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.ToVList().AsLNode(S.Braces), LNode.Literal(false)));
}
}
return null;
}
/// <summary>
/// Spawns a random <see cref="Vehicle"/>, wraps it and adds it to a specific <see cref="WList{TEntity}"/>.
/// </summary>
/// <param name="list">The wrapped list.</param>
/// <param name="position">The position.</param>
/// <param name="heading">The heading of the vehicle.</param>
/// <returns></returns>
public static WVehicle CreateRandomVehicle(this WList <WVehicle> list, Vector3 position, float heading = 0f)
{
if (list == null)
{
throw new ArgumentNullException(nameof(list));
}
if (position == null)
{
throw new ArgumentNullException(nameof(position));
}
var vehicle = new WVehicle(list.CallbackManager, World.CreateRandomVehicle(position, heading));
list.Add(vehicle);
return(vehicle);
}
/// <summary>
/// Spawns a <see cref="Ped"/>, wraps it and adds it to a specific <see cref="WList{TEntity}"/>.
/// </summary>
/// <param name="list">The wrapped list.</param>
/// <param name="modelHash">The world model.</param>
/// <param name="position">The position.</param>
/// <param name="heading">The heading of the ped.</param>
/// <returns></returns>
public static WPed CreatePed(this WList <WPed> list, PedHash modelHash, Vector3 position, float heading = 0f)
{
if (list == null)
{
throw new ArgumentNullException(nameof(list));
}
if (position == null)
{
throw new ArgumentNullException(nameof(position));
}
var ped = new WPed(list.CallbackManager, World.CreatePed(modelHash, position, heading));
list.Add(ped);
return(ped);
}
protected LNode SingleExprInside(Token group, string stmtType, WList <LNode> list = null, bool allowUnassignedVarDecl = false)
{
list = list ?? new WList <LNode>();
int oldCount = list.Count;
AppendExprsInside(group, list, false, allowUnassignedVarDecl);
if (list.Count != oldCount + 1)
{
if (list.Count <= oldCount)
{
LNode result = F.Id(S.Missing, group.StartIndex + 1, group.StartIndex + 1);
list.Add(result);
Error(result, "Missing expression inside '{0}'", stmtType);
return(result);
}
else
{
Error(list[1], "There should be only one expression inside '{0}'", stmtType);
list.Resize(oldCount + 1);
}
}
return(list[0]);
}
/// <summary>
/// Spawns a <see cref="Prop"/>, wraps it and adds it to a specific <see cref="WList{TEntity}"/>.
/// </summary>
/// <param name="list">The wrapped list.</param>
/// <param name="model">The world model.</param>
/// <param name="position">The position.</param>
/// <param name="rotation">The rotation.</param>
/// <param name="dynamic">Whether the prop should be dynamic.</param>
/// <param name="placeOnGround">Whether to place the prop on the ground.</param>
/// <returns></returns>
public static WProp CreateProp(this WList <WProp> list, Model model, Vector3 position, Vector3 rotation = default(Vector3), bool dynamic = true,
bool placeOnGround = true)
{
if (list == null)
{
throw new ArgumentNullException(nameof(list));
}
if (position == null)
{
throw new ArgumentNullException(nameof(position));
}
if (rotation == null)
{
throw new ArgumentNullException(nameof(rotation));
}
var prop = new WProp(list.CallbackManager, World.CreateProp(model, position, rotation, dynamic, placeOnGround));
list.Add(prop);
return(prop);
}
Mode = MacroMode.ProcessChildrenBefore)] // post-normal-macro-expansion
public static LNode with(LNode fn, IMacroContext context)
{
LNode braces;
if (fn.ArgCount != 2 || !(braces = fn.Args[1]).Calls(S.Braces))
{
return(null);
}
LNode tmp = F.Id(NextTempName(context));
WList <LNode> stmts = braces.Args.ToWList();
stmts = stmts.SmartSelect(stmt =>
stmt.ReplaceRecursive(expr => {
if (expr.Calls(S.Dot, 1))
{
return(expr.WithArgs(new VList <LNode>(tmp, expr.Args.Last)));
}
else if (expr.IsIdNamed("#"))
{
return(tmp);
}
return(null);
}));
stmts.Insert(0, F.Var(null, tmp.Name, fn.Args[0]));
if (IsExpressionContext(context))
{
stmts.Add(tmp);
return(F.Call("#runSequence", stmts.ToVList()));
}
else
{
return(F.Braces(stmts.ToVList()));
}
}
public static LNode unroll(LNode var, VList <LNode> 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(Pair.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.ToVList()));
}
protected LNode GeneratePredictionTreeCode(PredictionTree tree, Pair <LNode, string>[] matchingCode, ref Symbol haveLoop)
{
var braces = F.Braces();
Debug.Assert(tree.Children.Count >= 1);
var alts = (Alts)_currentPred;
if (tree.Children.Count == 1)
{
return(GetPredictionSubtreeCode(tree.Children[0], matchingCode, ref haveLoop));
}
// From the prediction table, we can generate either an if-else chain:
//
// if (la0 >= '0' && la0 <= '7') sub_tree_1();
// else if (la0 == '-') sub_tree_2();
// else break;
//
// or a switch statement:
//
// switch(la0) {
// case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7':
// sub_tree_1();
// break;
// case '-':
// sub_tree_2();
// break;
// default:
// goto breakfor;
// }
//
// Assertion levels always need an if-else chain; lookahead levels
// consider the complexity of switch vs if and decide which is most
// appropriate. Generally "if" is slower, but a switch may require
// too many labels since it doesn't support ranges like "la0 >= 'a'
// && la0 <= 'z'".
//
// This class makes if-else chains directly (using IPGTerminalSet.
// GenerateTest() to generate the test expressions), but the code
// generation helper (CGH) is used to generate switch statements
// because the required code may be more complex.
//
// We may or may not be generating code inside a for(;;) loop. If we
// decide to generate a switch() statement, one of the branches will
// usually need to break out of the for loop, but "break" can only
// break out of the switch(). In that case, add "stop:" after the
// switch() and use "goto stop" instead of "break".
WList <LNode> block = new WList <LNode>();
LNode laVar = null;
MSet <int> switchCases = new MSet <int>();
IPGTerminalSet[] branchSets = null;
bool should = false;
if (tree.UsesLA())
{
laVar = F.Id("la" + tree.Lookahead.ToString());
if (!tree.IsAssertionLevel)
{
IPGTerminalSet covered = CGH.EmptySet;
branchSets = tree.Children.Select(branch => {
var set = branch.Set.Subtract(covered);
covered = covered.Union(branch.Set);
return(set);
}).ToArray();
should = CGH.ShouldGenerateSwitch(branchSets, switchCases, tree.Children.Last.IsErrorBranch);
if (!should)
{
switchCases.Clear();
}
else if (should && haveLoop == S.For)
{
// Can't "break" out of the for-loop when there is a nested switch,
haveLoop = GSymbol.Get(NextStopLabel()); // so use "goto stop".
}
}
}
LNode[] branchCode = new LNode[tree.Children.Count];
for (int i = 0; i < tree.Children.Count; i++)
{
if (tree.Children[i].IsErrorBranch)
{
if (_recognizerMode)
{
branchCode[i] = F.Call(S.Return, F.False);
}
else if (alts.ErrorBranch != null && alts.ErrorBranch != DefaultErrorBranch.Value)
{
Debug.Assert(matchingCode.Length == alts.Arms.Count + 1);
branchCode[i] = matchingCode[alts.Arms.Count].A;
}
else
{
branchCode[i] = CGH.ErrorBranch(tree.TotalCoverage, tree.Lookahead);
}
}
else
{
branchCode[i] = GetPredictionSubtreeCode(tree.Children[i], matchingCode, ref haveLoop);
}
}
var code = GenerateIfElseChain(tree, branchCode, ref laVar, switchCases);
if (laVar != null)
{
block.Insert(0, F.Assign(laVar, CGH.LA(tree.Lookahead)));
_laVarsNeeded |= 1ul << tree.Lookahead;
}
else if (should)
{
laVar = CGH.LA(tree.Lookahead);
}
if (should)
{
Debug.Assert(switchCases.Count != 0);
code = CGH.GenerateSwitch(branchSets, branchCode, switchCases, code ?? F.Missing, laVar);
}
block.Add(code);
return(F.Braces(block.ToVList()));
}
public static LNode match(LNode node, IMacroContext context)
{
{
LNode input;
VList <LNode> 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 VList <LNode>(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.Statement));
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.ToVList().AsLNode(S.Braces), LNode.Literal(false))));
}
}
return(null);
}
public static LNode UnpackTuple(LNode node, IMessageSink sink)
{
var a = node.Args;
if (a.Count == 2 && a[0].CallsMin(S.Tuple, 1)) {
var output = new WList<LNode>();
var tuple = a[0].Args;
var rhs = a[1];
// Avoid evaluating rhs more than once, if it doesn't look like a simple variable
rhs = MaybeAddTempVarDecl(rhs, output);
for (int i = 0; i < tuple.Count; i++) {
var itemi = F.Dot(rhs, F.Id(GSymbol.Get("Item" + (i + 1))));
if (tuple[i].Calls(S.Var, 2))
output.Add(F.Var(tuple[i].Args[0], tuple[i].Args[1], itemi));
else
output.Add(F.Call(S.Assign, tuple[i], itemi));
}
return F.Call(S.Splice, output.ToVList());
}
return null;
}
public static LNode matchCode(LNode node, IMacroContext context)
{
if (node.AttrNamed(S.Static) != null)
return null; // this case is handled by static_matchCode macro
var args_body = context.GetArgsAndBody(false);
VList<LNode> args = args_body.Item1, body = args_body.Item2;
if (args.Count != 1 || body.Count < 1)
return null;
var cases = GetCases(body, context.Sink);
if (cases.IsEmpty)
return null;
var output = new WList<LNode>();
var @var = MaybeAddTempVarDecl(context, args[0], output);
var ifClauses = new List<Pair<LNode, LNode>>();
var cmc = new CodeMatchContext {
Context = context
};
foreach (var @case in cases)
{
cmc.ThenClause.Clear();
// e.g. case [$(..._)] Foo($x + 1, $y) =>
// LNode x, y, tmp9;
// if (var.Calls((Symbol) "Foo", 2) && (tmp9 = var.Args[0]).Calls(CodeSymbols.Plus, 2)
// && (x = tmp9.Args[0]) != null // this will never be null, but we want to put it the assignment in the 'if' statement
// && 1.Equals(tmp9.Args[1].Value) && (y = var.Args[1]) != null) { ... }
LNode testExpr = null;
if (@case.Key.Count > 0) {
if (cmc.IsMultiCase = @case.Key.Count > 1) {
cmc.UsageCounters.Clear();
testExpr = @case.Key.Aggregate((LNode) null, (test, pattern) => {
test = LNode.MergeBinary(test, cmc.MakeTopTestExpr(pattern, @var), S.Or);
return test;
});
foreach (var pair in cmc.UsageCounters.Where(p => p.Value < @case.Key.Count)) {
if (cmc.NodeVars.ContainsKey(pair.Key))
cmc.NodeVars[pair.Key] = true;
if (cmc.ListVars.ContainsKey(pair.Key))
cmc.ListVars[pair.Key] = true;
}
} else
testExpr = cmc.MakeTopTestExpr(@case.Key[0], @var);
}
var handler = @case.Value.AsLNode(S.Braces);
if (cmc.ThenClause.Count > 0)
handler = LNode.MergeLists(F.Braces(cmc.ThenClause), handler, S.Braces);
ifClauses.Add(Pair.Create(testExpr, handler));
}
LNode ifStmt = null;
for (int i = ifClauses.Count - 1; i >= 0; i--)
{
if (ifClauses[i].Item1 == null) {
if (ifStmt == null)
ifStmt = ifClauses[i].Item2;
else
context.Sink.Error(node, "The default case must appear last, and there can be only one.");
} else {
if (ifStmt == null)
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2);
else
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2, ifStmt);
}
}
if (cmc.NodeVars.Count > 0)
output.Add(F.Call(S.Var, ListExt.Single(F.Id("LNode")).Concat(
cmc.NodeVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? F.Call(S.Assign, F.Id(kvp.Key), F.Null) : F.Id(kvp.Key)))));
if (cmc.ListVars.Count > 0) {
LNode type = LNode.Call(CodeSymbols.Of, LNode.List(LNode.Id((Symbol) "VList"), LNode.Id((Symbol) "LNode"))).SetStyle(NodeStyle.Operator);
output.Add(F.Call(S.Var, ListExt.Single(type).Concat(
cmc.ListVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(kvp.Key), LNode.Call(CodeSymbols.Default, LNode.List(type)))).SetStyle(NodeStyle.Operator) : F.Id(kvp.Key)))));
}
if (output.Count == 0)
return ifStmt;
else {
output.Add(ifStmt);
return F.Braces(output.ToVList());
}
}
private void AddSwitchHandler(LNode branch, WList<LNode> stmts)
{
stmts.SpliceAdd(branch, S.Splice);
if (EndMayBeReachable(branch))
stmts.Add(F.Call(S.Break));
}
private WList<LNode> GenerateExtraMatchingCode(Pair<LNode, string>[] matchingCode, int separateCount, ref Symbol loopType)
{
var extraMatching = new WList<LNode>();
if (separateCount != 0) {
for (int i = 0; i < matchingCode.Length; i++) {
if (matchingCode[i].B != null) // split out this case
{
var label = F.Id(matchingCode[i].B);
// break/continue; matchN: matchingCode[i].A;
if (extraMatching.Count > 0)
extraMatching.Add(GetContinueStmt(loopType));
extraMatching.Add(F.Call(S.Label, label));
extraMatching.Add(matchingCode[i].A);
//skipCount++;
// put @@{ goto matchN; } in prediction tree
matchingCode[i].A = F.Call(S.Goto, label);
}
}
}
return extraMatching;
}
[LexicalMacro("matchCode (var) { case ...: ... }; // In LES, use a => b instead of case a: b", "Attempts to match and deconstruct a Loyc tree against a series of cases with patterns, e.g. " + "`case $a + $b:` expects a tree that calls `+` with two parameters, placed in new variables called a and b. " + "`break` is not required or recognized at the end of each case's handler (code block). " + "Use `$(...x)` to gather zero or more parameters into a list `x`. " + "Use `case pattern1, pattern2:` in EC# to handle multiple cases with the same handler.")] public static LNode matchCode(LNode node, IMacroContext context)
{
var args_body = context.GetArgsAndBody(true);
VList<LNode> args = args_body.Item1, body = args_body.Item2;
if (args.Count != 1 || body.Count < 1)
return null;
var cases = GetCases(body, context.Sink);
if (cases.IsEmpty)
return null;
var output = new WList<LNode>();
var @var = MaybeAddTempVarDecl(args[0], output);
var ifClauses = new List<Pair<LNode,LNode>>();
var cmc = new CodeMatchContext {
Context = context
};
foreach (var @case in cases) {
cmc.ThenClause.Clear();
LNode testExpr = null;
if (@case.Key.Count > 0) {
if (cmc.IsMultiCase = @case.Key.Count > 1) {
cmc.UsageCounters.Clear();
testExpr = @case.Key.Aggregate((LNode) null, (test, pattern) => {
test = LNode.MergeBinary(test, cmc.MakeTopTestExpr(pattern, @var), S.Or);
return test;
});
foreach (var pair in cmc.UsageCounters.Where(p => p.Value < @case.Key.Count)) {
if (cmc.NodeVars.ContainsKey(pair.Key))
cmc.NodeVars[pair.Key] = true;
if (cmc.ListVars.ContainsKey(pair.Key))
cmc.ListVars[pair.Key] = true;
}
} else
testExpr = cmc.MakeTopTestExpr(@case.Key[0], @var);
}
var handler = @case.Value;
if (cmc.ThenClause.Count > 0)
handler = LNode.MergeLists(F.Braces(cmc.ThenClause), handler, S.Braces);
ifClauses.Add(Pair.Create(testExpr, handler));
}
LNode ifStmt = null;
for (int i = ifClauses.Count - 1; i >= 0; i--) {
if (ifClauses[i].Item1 == null) {
if (ifStmt == null)
ifStmt = ifClauses[i].Item2;
else
context.Sink.Write(Severity.Error, node, "The default case must appear last, and there can be only one.");
} else {
if (ifStmt == null)
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2);
else
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2, ifStmt);
}
}
if (cmc.NodeVars.Count > 0)
output.Add(F.Call(S.Var, ListExt.Single(F.Id("LNode")).Concat(cmc.NodeVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? F.Call(S.Assign, F.Id(kvp.Key), F.Null) : F.Id(kvp.Key)))));
if (cmc.ListVars.Count > 0) {
LNode type = LNode.Call(CodeSymbols.Of, LNode.List(LNode.Id((Symbol) "VList"), LNode.Id((Symbol) "LNode")));
output.Add(F.Call(S.Var, ListExt.Single(type).Concat(cmc.ListVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(kvp.Key), LNode.Call(CodeSymbols.Default, LNode.List(type)))).SetStyle(NodeStyle.Operator) : F.Id(kvp.Key)))));
}
if (output.Count == 0)
return ifStmt;
else {
output.Add(ifStmt);
return F.Braces(output.ToVList());
}
}
public virtual LNode GenerateSwitch(IPGTerminalSet[] branchSets, MSet<int> casesToInclude, LNode[] branchCode, LNode defaultBranch, LNode laVar)
{
Debug.Assert(branchSets.Length == branchCode.Length);
WList<LNode> stmts = new WList<LNode>();
for (int i = 0; i < branchSets.Length; i++)
{
if (casesToInclude.Contains(i))
{
foreach (LNode value in GetCases(branchSets[i]))
{
stmts.Add(F.Call(S.Case, value));
if (stmts.Count > 65535) // sanity check
throw new InvalidOperationException("switch is too large to generate");
}
AddSwitchHandler(branchCode[i], stmts);
}
}
if (!defaultBranch.IsIdNamed(S.Missing))
{
stmts.Add(F.Call(S.Label, F.Id(S.Default)));
AddSwitchHandler(defaultBranch, stmts);
}
return F.Call(S.Switch, (LNode)laVar, F.Braces(stmts.ToVList()));
}
private void MakeTestExpr(LNode pattern, LNode candidate, out Symbol varArgSym, out LNode varArgCond)
{
varArgSym = null; varArgCond = null;
// is this a $substitutionVar?
LNode condition;
bool isParams, refExistingVar;
var nodeVar = DecodeSubstitutionExpr(pattern, out condition, out isParams, out refExistingVar);
// Unless the candidate is a simple variable name, avoid repeating
// it by creating a temporary variable to hold its value
int predictedTests = pattern.Attrs.Count +
(nodeVar != null ? 0 : pattern.Args.Count) +
(!pattern.HasSimpleHeadWithoutPAttrs() ? 1 : 0);
if (predictedTests > 1)
{
candidate = MaybePutCandidateInTempVar(candidate.IsCall, candidate);
}
MatchAttributes(pattern, candidate); // Look for @[$(...var)]
// case $_
if (nodeVar != null)
{
if (nodeVar != __ || condition != null)
{
if (!refExistingVar)
{
AddVar(nodeVar, isParams, errAt: pattern);
}
if (!isParams)
{
var assignment = LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(nodeVar), candidate)).SetStyle(NodeStyle.Operator);
Tests.Add(LNode.Call(CodeSymbols.NotEq, LNode.List(assignment.PlusAttrs(LNode.List(LNode.InParensTrivia)), LNode.Literal(null))).SetStyle(NodeStyle.Operator));
Tests.Add(condition);
}
}
if (isParams)
{
varArgSym = nodeVar;
varArgCond = condition;
return;
}
}
else if (pattern.IsId)
{
Tests.Add(LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"IsIdNamed"))).SetStyle(NodeStyle.Operator), LNode.List(LNode.Call(CodeSymbols.Cast, LNode.List(F.Literal(pattern.Name.Name), LNode.Id((Symbol)"Symbol"))).SetStyle(NodeStyle.Operator))));
}
else if (pattern.IsLiteral)
{
if (pattern.Value == null)
{
Tests.Add(LNode.Call(CodeSymbols.Eq, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Value"))).SetStyle(NodeStyle.Operator), LNode.Literal(null))).SetStyle(NodeStyle.Operator));
}
else
{
Tests.Add(LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(pattern, LNode.Id((Symbol)"Equals"))).SetStyle(NodeStyle.Operator), LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Value"))).SetStyle(NodeStyle.Operator))));
}
}
else // call(...)
{
int?varArgAt;
int fixedArgC = GetFixedArgCount(pattern.Args, out varArgAt);
// Test if the call target matches
var pTarget = pattern.Target;
if (pTarget.IsId && !pTarget.HasPAttrs())
{
var quoteTarget = QuoteSymbol(pTarget.Name);
LNode targetTest;
if (varArgAt.HasValue && fixedArgC == 0)
{
targetTest = LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Calls"))).SetStyle(NodeStyle.Operator), LNode.List(quoteTarget));
}
else if (varArgAt.HasValue)
{
targetTest = LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"CallsMin"))).SetStyle(NodeStyle.Operator), LNode.List(quoteTarget, F.Literal(fixedArgC)));
}
else
{
targetTest = LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Calls"))).SetStyle(NodeStyle.Operator), LNode.List(quoteTarget, F.Literal(fixedArgC)));
}
Tests.Add(targetTest);
}
else
{
if (fixedArgC == 0)
{
Tests.Add(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"IsCall"))).SetStyle(NodeStyle.Operator));
if (!varArgAt.HasValue)
{
Tests.Add(LNode.Call(CodeSymbols.Eq, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Args"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"Count"))).SetStyle(NodeStyle.Operator), LNode.Literal(0))).SetStyle(NodeStyle.Operator));
}
}
else
{
var op = varArgAt.HasValue ? S.GE : S.Eq;
Tests.Add(LNode.Call(op, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Args"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"Count"))).SetStyle(NodeStyle.Operator), F.Literal(fixedArgC))));
}
int i = Tests.Count;
MakeTestExpr(pTarget, LNode.Call(CodeSymbols.Dot, LNode.List(candidate, LNode.Id((Symbol)"Target"))).SetStyle(NodeStyle.Operator));
}
MakeArgListTests(pattern.Args, ref candidate);
}
}
public static LNode matchCode(LNode node, IMacroContext context)
{
if (node.AttrNamed(S.Static) != null)
{
return(null); // this case is handled by static_matchCode macro
}
var args_body = context.GetArgsAndBody(false);
LNodeList args = args_body.Item1, body = args_body.Item2;
if (args.Count != 1 || body.Count < 1)
{
return(null);
}
var cases = GetCases(body, context.Sink);
if (cases.IsEmpty)
{
return(null);
}
var output = new WList <LNode>();
var var = MaybeAddTempVarDecl(context, args[0], output);
var ifClauses = new List <Pair <LNode, LNode> >();
var cmc = new CodeMatchContext {
Context = context
};
foreach (var @case in cases)
{
cmc.ThenClause.Clear();
// e.g. case [$(..._)] Foo($x + 1, $y) =>
// LNode x, y, tmp9;
// if (var.Calls((Symbol) "Foo", 2) && (tmp9 = var.Args[0]).Calls(CodeSymbols.Plus, 2)
// && (x = tmp9.Args[0]) != null // this will never be null, but we want to put it the assignment in the 'if' statement
// && 1.Equals(tmp9.Args[1].Value) && (y = var.Args[1]) != null) { ... }
LNode testExpr = null;
if (@case.Key.Count > 0)
{
if (cmc.IsMultiCase = @case.Key.Count > 1)
{
cmc.UsageCounters.Clear();
testExpr = @case.Key.Aggregate((LNode)null, (test, pattern) => {
test = LNode.MergeBinary(test, cmc.MakeTopTestExpr(pattern, var), S.Or);
return(test);
});
foreach (var pair in cmc.UsageCounters.Where(p => p.Value < @case.Key.Count))
{
if (cmc.NodeVars.ContainsKey(pair.Key))
{
cmc.NodeVars[pair.Key] = true;
}
if (cmc.ListVars.ContainsKey(pair.Key))
{
cmc.ListVars[pair.Key] = true;
}
}
}
else
{
testExpr = cmc.MakeTopTestExpr(@case.Key[0], var);
}
}
var handler = F.Braces(@case.Value);
if (cmc.ThenClause.Count > 0)
{
handler = LNode.MergeLists(F.Braces(cmc.ThenClause), handler, S.Braces);
}
ifClauses.Add(Pair.Create(testExpr, handler));
}
LNode ifStmt = null;
for (int i = ifClauses.Count - 1; i >= 0; i--)
{
if (ifClauses[i].Item1 == null)
{
if (ifStmt == null)
{
ifStmt = ifClauses[i].Item2;
}
else
{
context.Sink.Error(node, "The default case must appear last, and there can be only one.");
}
}
else
{
if (ifStmt == null)
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2);
}
else
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2, ifStmt);
}
}
}
if (cmc.NodeVars.Count > 0)
{
output.Add(F.Call(S.Var, ListExt.Single(F.Id("LNode")).Concat(
cmc.NodeVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? F.Call(S.Assign, F.Id(kvp.Key), F.Null) : F.Id(kvp.Key)))));
}
if (cmc.ListVars.Count > 0)
{
LNode type = LNode.Id((Symbol)"LNodeList");
output.Add(F.Call(S.Var, ListExt.Single(type).Concat(
cmc.ListVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(kvp.Key), LNode.Call(CodeSymbols.Default, LNode.List(type)))).SetStyle(NodeStyle.Operator) : F.Id(kvp.Key)))));
}
if (output.Count == 0)
{
return(ifStmt.IncludingTriviaFrom(node));
}
else
{
output.Add(ifStmt);
return(F.Braces(output.ToVList()).IncludingTriviaFrom(node));
}
}
public static LNode @try(LNode node, IMessageSink sink)
{
if (!node.IsCall)
return null;
// try(code, catch, Exception::e, handler, catch, ..., finally, handler)
// ...becomes...
// #try(#{ stmt1; stmt2; ... }, #catch(#var(Exception, e), handler), #finally(handler))
LNode finallyCode = null;
WList<LNode> clauses = new WList<LNode>();
var parts = node.Args;
for (int i = parts.Count-2; i >= 1; i -= 2)
{
var p = parts[i];
if (p.IsIdNamed(_finally)) {
if (clauses.Count != 0 || finallyCode != null)
sink.Write(Severity.Error, p, "The «finally» clause must come last, there can only be one of them.");
finallyCode = parts[i+1];
} else if (p.Name == _catch) {
if (p.ArgCount > 0) {
if (p.ArgCount > 1)
sink.Write(Severity.Error, p, "Expected catch() to take one argument.");
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, p.Args[0], F.Missing, parts[i + 1]));
} else {
// This is a catch-all clause (the type argument is missing)
if (clauses.Count != 0)
sink.Write(Severity.Error, p, "The catch-all clause must be the last «catch» clause.");
clauses.Add(F.Call(S.Catch, F.Missing, F.Missing, parts[i + 1]));
}
} else if (i > 1 && parts[i-1].IsIdNamed(_catch)) {
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, AutoRemoveParens(p), F.Missing, parts[i+1]));
i--;
} else {
return Reject(sink, p, "Expected «catch» or «finally» clause here. Clause is missing or malformed.");
}
if (i == 2)
return Reject(sink, parts[1], "Expected «catch» or «finally» clause here. Clause is missing or malformed.");
}
if (clauses.Count == 0 && finallyCode == null) {
Debug.Assert(node.ArgCount <= 1);
return Reject(sink, node, "Missing «catch, Type, Code» or «finally, Code» clause");
}
if (finallyCode != null)
clauses.Add(F.Call(S.Finally, finallyCode));
clauses.Insert(0, node.Args[0]);
return node.With(S.Try, clauses.ToVList());
}
[LexicalMacro("matchCode (var) { case ...: ... }; // In LES, use a => b instead of case a: b", "Attempts to match and deconstruct a Loyc tree against a series of cases with patterns, e.g. " + "`case $a + $b:` expects a tree that calls `+` with two parameters, placed in new variables called a and b. " + "`break` is not required or recognized at the end of each case's handler (code block). " + "Use `$(...x)` to gather zero or more parameters into a list `x`. " + "Use `case pattern1, pattern2:` in EC# to handle multiple cases with the same handler.")] public static LNode matchCode(LNode node, IMacroContext context)
{
var args_body = context.GetArgsAndBody(true);
VList <LNode> args = args_body.Item1, body = args_body.Item2;
if (args.Count != 1 || body.Count < 1)
{
return(null);
}
var cases = GetCases(body, context.Sink);
if (cases.IsEmpty)
{
return(null);
}
var output = new WList <LNode>();
var @var = MaybeAddTempVarDecl(args[0], output);
var ifClauses = new List <Pair <LNode, LNode> >();
var cmc = new CodeMatchContext {
Context = context
};
foreach (var @case in cases)
{
cmc.ThenClause.Clear();
LNode testExpr = null;
if (@case.Key.Count > 0)
{
if (cmc.IsMultiCase = @case.Key.Count > 1)
{
cmc.UsageCounters.Clear();
testExpr = @case.Key.Aggregate((LNode)null, (test, pattern) => {
test = LNode.MergeBinary(test, cmc.MakeTopTestExpr(pattern, @var), S.Or);
return(test);
});
foreach (var pair in cmc.UsageCounters.Where(p => p.Value < @case.Key.Count))
{
if (cmc.NodeVars.ContainsKey(pair.Key))
{
cmc.NodeVars[pair.Key] = true;
}
if (cmc.ListVars.ContainsKey(pair.Key))
{
cmc.ListVars[pair.Key] = true;
}
}
}
else
{
testExpr = cmc.MakeTopTestExpr(@case.Key[0], @var);
}
}
var handler = @case.Value;
if (cmc.ThenClause.Count > 0)
{
handler = LNode.MergeLists(F.Braces(cmc.ThenClause), handler, S.Braces);
}
ifClauses.Add(Pair.Create(testExpr, handler));
}
LNode ifStmt = null;
for (int i = ifClauses.Count - 1; i >= 0; i--)
{
if (ifClauses[i].Item1 == null)
{
if (ifStmt == null)
{
ifStmt = ifClauses[i].Item2;
}
else
{
context.Sink.Write(Severity.Error, node, "The default case must appear last, and there can be only one.");
}
}
else
{
if (ifStmt == null)
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2);
}
else
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2, ifStmt);
}
}
}
if (cmc.NodeVars.Count > 0)
{
output.Add(F.Call(S.Var, ListExt.Single(F.Id("LNode")).Concat(cmc.NodeVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? F.Call(S.Assign, F.Id(kvp.Key), F.Null) : F.Id(kvp.Key)))));
}
if (cmc.ListVars.Count > 0)
{
LNode type = LNode.Call(CodeSymbols.Of, LNode.List(LNode.Id((Symbol)"VList"), LNode.Id((Symbol)"LNode")));
output.Add(F.Call(S.Var, ListExt.Single(type).Concat(cmc.ListVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(kvp.Key), LNode.Call(CodeSymbols.Default, LNode.List(type)))).SetStyle(NodeStyle.Operator) : F.Id(kvp.Key)))));
}
if (output.Count == 0)
{
return(ifStmt);
}
else
{
output.Add(ifStmt);
return(F.Braces(output.ToVList()));
}
}
public static LNode matchCode(LNode node, IMacroContext context)
{
var args_body = context.GetArgsAndBody(true);
VList <LNode> args = args_body.Item1, body = args_body.Item2;
if (args.Count != 1 || body.Count < 1)
{
return(null);
}
var cases = GetCases(body, context.Sink);
if (cases.IsEmpty)
{
return(null);
}
var output = new WList <LNode>();
var @var = MaybeAddTempVarDecl(context, args[0], output);
var ifClauses = new List <Pair <LNode, LNode> >();
var cmc = new CodeMatchContext {
Context = context
};
foreach (var @case in cases)
{
cmc.ThenClause.Clear();
LNode testExpr = null;
if (@case.Key.Count > 0)
{
if (cmc.IsMultiCase = @case.Key.Count > 1)
{
cmc.UsageCounters.Clear();
testExpr = @case.Key.Aggregate((LNode)null, (test, pattern) => {
test = LNode.MergeBinary(test, cmc.MakeTopTestExpr(pattern, @var), S.Or);
return(test);
});
foreach (var pair in cmc.UsageCounters.Where(p => p.Value < @case.Key.Count))
{
if (cmc.NodeVars.ContainsKey(pair.Key))
{
cmc.NodeVars[pair.Key] = true;
}
if (cmc.ListVars.ContainsKey(pair.Key))
{
cmc.ListVars[pair.Key] = true;
}
}
}
else
{
testExpr = cmc.MakeTopTestExpr(@case.Key[0], @var);
}
}
var handler = @case.Value;
if (cmc.ThenClause.Count > 0)
{
handler = LNode.MergeLists(F.Braces(cmc.ThenClause), handler, S.Braces);
}
ifClauses.Add(Pair.Create(testExpr, handler));
}
LNode ifStmt = null;
for (int i = ifClauses.Count - 1; i >= 0; i--)
{
if (ifClauses[i].Item1 == null)
{
if (ifStmt == null)
{
ifStmt = ifClauses[i].Item2;
}
else
{
context.Sink.Write(Severity.Error, node, "The default case must appear last, and there can be only one.");
}
}
else
{
if (ifStmt == null)
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2);
}
else
{
ifStmt = F.Call(S.If, ifClauses[i].Item1, ifClauses[i].Item2, ifStmt);
}
}
}
if (cmc.NodeVars.Count > 0)
{
output.Add(F.Call(S.Var, ListExt.Single(F.Id("LNode")).Concat(cmc.NodeVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? F.Call(S.Assign, F.Id(kvp.Key), F.Null) : F.Id(kvp.Key)))));
}
if (cmc.ListVars.Count > 0)
{
LNode type = LNode.Call(CodeSymbols.Of, LNode.List(LNode.Id((Symbol)"VList"), LNode.Id((Symbol)"LNode")));
output.Add(F.Call(S.Var, ListExt.Single(type).Concat(cmc.ListVars.OrderBy(v => v.Key.Name).Select(kvp => kvp.Value ? LNode.Call(CodeSymbols.Assign, LNode.List(F.Id(kvp.Key), LNode.Call(CodeSymbols.Default, LNode.List(type)))).SetStyle(NodeStyle.Operator) : F.Id(kvp.Key)))));
}
if (output.Count == 0)
{
return(ifStmt);
}
else
{
output.Add(ifStmt);
return(F.Braces(output.ToVList()));
}
}
public static LNode @try(LNode node, IMessageSink sink)
{
if (!node.IsCall)
{
return(null);
}
// try(code, catch, Exception::e, handler, catch, ..., finally, handler)
// ...becomes...
// #try(#{ stmt1; stmt2; ... }, #catch(#var(Exception, e), handler), #finally(handler))
LNode finallyCode = null;
WList <LNode> clauses = new WList <LNode>();
var parts = node.Args;
for (int i = parts.Count - 2; i >= 1; i -= 2)
{
var p = parts[i];
if (p.IsIdNamed(_finally))
{
if (clauses.Count != 0 || finallyCode != null)
{
sink.Write(Severity.Error, p, "The «finally» clause must come last, there can only be one of them.");
}
finallyCode = parts[i + 1];
}
else if (p.Name == _catch)
{
if (p.ArgCount > 0)
{
if (p.ArgCount > 1)
{
sink.Write(Severity.Error, p, "Expected catch() to take one argument.");
}
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, p.Args[0], F.Missing, parts[i + 1]));
}
else
{
// This is a catch-all clause (the type argument is missing)
if (clauses.Count != 0)
{
sink.Write(Severity.Error, p, "The catch-all clause must be the last «catch» clause.");
}
clauses.Add(F.Call(S.Catch, F.Missing, F.Missing, parts[i + 1]));
}
}
else if (i > 1 && parts[i - 1].IsIdNamed(_catch))
{
// This is a normal catch clause
clauses.Insert(0, F.Call(S.Catch, AutoRemoveParens(p), F.Missing, parts[i + 1]));
i--;
}
else
{
return(Reject(sink, p, "Expected «catch» or «finally» clause here. Clause is missing or malformed."));
}
if (i == 2)
{
return(Reject(sink, parts[1], "Expected «catch» or «finally» clause here. Clause is missing or malformed."));
}
}
if (clauses.Count == 0 && finallyCode == null)
{
Debug.Assert(node.ArgCount <= 1);
return(Reject(sink, node, "Missing «catch, Type, Code» or «finally, Code» clause"));
}
if (finallyCode != null)
{
clauses.Add(F.Call(S.Finally, finallyCode));
}
clauses.Insert(0, node.Args[0]);
return(node.With(S.Try, clauses.ToVList()));
}
public override LNode GenerateMatchExpr(IPGTerminalSet set_, bool savingResult, bool recognizerMode)
{
var set = (PGIntSet)set_;
LNode call;
var type = set.ChooseMatchType(2, 4);
if (type != PGIntSet.Match.Set) {
var args = new WList<LNode>();
if (type == PGIntSet.Match.Ranges) {
// Use MatchRange or MatchExceptRange
foreach (var r in set) {
if (!set.IsInverted || r.Lo != EOF_int || r.Hi != EOF_int) {
args.Add((LNode)set.MakeLiteral(r.Lo));
args.Add((LNode)set.MakeLiteral(r.Hi));
}
}
var target = recognizerMode
? (set.IsInverted ? _TryMatchExceptRange : _TryMatchRange)
: (set.IsInverted ? _MatchExceptRange : _MatchRange);
call = ApiCall(target, args);
} else {
// Use Match or MatchExcept
foreach (var r in set) {
for (int c = r.Lo; c <= r.Hi; c++) {
if (!set.IsInverted || c != EOF_int)
args.Add((LNode)set.MakeLiteral(c));
}
}
var target = recognizerMode
? (set.IsInverted ? _TryMatchExcept : _TryMatch)
: (set.IsInverted ? _MatchExcept : _Match);
call = ApiCall(target, args.ToVList());
}
} else {
var setName = GenerateSetDecl(set);
if (set.IsInverted)
call = ApiCall(recognizerMode ? _TryMatchExcept : _MatchExcept, F.Id(setName));
else
call = ApiCall(recognizerMode ? _TryMatch : _Match, F.Id(setName));
}
return call;
}
protected LNode GeneratePredictionTreeCode(PredictionTree tree, Pair<LNode, string>[] matchingCode, ref Symbol haveLoop)
{
var braces = F.Braces();
Debug.Assert(tree.Children.Count >= 1);
var alts = (Alts)_currentPred;
if (tree.Children.Count == 1)
return GetPredictionSubtreeCode(tree.Children[0], matchingCode, ref haveLoop);
// From the prediction table, we can generate either an if-else chain:
//
// if (la0 >= '0' && la0 <= '7') sub_tree_1();
// else if (la0 == '-') sub_tree_2();
// else break;
//
// or a switch statement:
//
// switch(la0) {
// case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7':
// sub_tree_1();
// break;
// case '-':
// sub_tree_2();
// break;
// default:
// goto breakfor;
// }
//
// Assertion levels always need an if-else chain; lookahead levels
// consider the complexity of switch vs if and decide which is most
// appropriate. Generally "if" is slower, but a switch may require
// too many labels since it doesn't support ranges like "la0 >= 'a'
// && la0 <= 'z'".
//
// This class makes if-else chains directly (using IPGTerminalSet.
// GenerateTest() to generate the test expressions), but the code
// snippet generator (CSG) is used to generate switch statements
// because the required code may be more complex.
//
// We may or may not be generating code inside a for(;;) loop. If we
// decide to generate a switch() statement, one of the branches will
// usually need to break out of the for loop, but "break" can only
// break out of the switch(). In that case, add "stop:" after the
// switch() and use "goto stop" instead of "break".
WList<LNode> block = new WList<LNode>();
LNode laVar = null;
MSet<int> switchCases = new MSet<int>();
IPGTerminalSet[] branchSets = null;
bool should = false;
if (tree.UsesLA()) {
laVar = F.Id("la" + tree.Lookahead.ToString());
if (!tree.IsAssertionLevel) {
IPGTerminalSet covered = CGH.EmptySet;
branchSets = tree.Children.Select(branch => {
var set = branch.Set.Subtract(covered);
covered = covered.Union(branch.Set);
return set;
}).ToArray();
should = CGH.ShouldGenerateSwitch(branchSets, switchCases, tree.Children.Last.IsErrorBranch);
if (!should)
switchCases.Clear();
else if (should && haveLoop == S.For)
// Can't "break" out of the for-loop when there is a nested switch,
haveLoop = GSymbol.Get(NextStopLabel()); // so use "goto stop".
}
}
LNode[] branchCode = new LNode[tree.Children.Count];
for (int i = 0; i < tree.Children.Count; i++)
if (tree.Children[i].IsErrorBranch) {
if (alts.ErrorBranch != null && alts.ErrorBranch != DefaultErrorBranch.Value) {
Debug.Assert(matchingCode.Length == alts.Arms.Count + 1);
branchCode[i] = matchingCode[alts.Arms.Count].A;
} else
branchCode[i] = CGH.ErrorBranch(tree.TotalCoverage, tree.Lookahead);
} else
branchCode[i] = GetPredictionSubtreeCode(tree.Children[i], matchingCode, ref haveLoop);
var code = GenerateIfElseChain(tree, branchCode, ref laVar, switchCases);
if (laVar != null) {
block.Insert(0, F.Assign(laVar, CGH.LA(tree.Lookahead)));
_laVarsNeeded |= 1ul << tree.Lookahead;
} else if (should)
laVar = CGH.LA(tree.Lookahead);
if (should) {
Debug.Assert(switchCases.Count != 0);
code = CGH.GenerateSwitch(branchSets, switchCases, branchCode, code, laVar);
}
block.Add(code);
return F.Braces(block.ToVList());
}
public static LNode @var(LNode node, IMessageSink sink)
{
var parts = node.Args;
if (parts.Count == 0)
{
return(Reject(sink, node, "A variable definition must have the form var(Name::Type), var(Name = value), or var(Name::Type = value)"));
}
if (parts[0].IsId)
{
return(null); // e.g. this is true for "static readonly x::Foo"
}
WList <LNode> varStmts = null;
LNode varStmt = null;
for (int i = 0; i < parts.Count; i++)
{
LNode part = parts[i], type = null, init = null;
if (part.Calls(S.Assign, 2))
{
init = part.Args[1];
part = part.Args[0];
}
if (part.Calls(S.ColonColon, 2))
{
type = part.Args[1];
part = part.Args[0];
}
if (init == null && part.Calls(S.Assign, 2))
{
init = part.Args[1];
part = part.Args[0];
}
if (!part.IsId)
{
return(Reject(sink, part, "Expected a simple variable name here"));
}
if (type != null && !IsComplexId(type))
{
return(Reject(sink, type, "Expected a type name here"));
}
type = type ?? F.Missing;
var nameAndInit = init == null ? part : F.Call(S.Assign, part, init);
if (varStmt != null && varStmt.Args[0].Equals(type))
{
// same type used again, e.g. (var x::int y::int) => (#var int x y)
varStmt = varStmt.WithArgs(varStmt.Args.Add(nameAndInit));
}
else
{
// first item (var x::int => #var int x) or type changed (var a::A b::B => #var A a; #var B b)
if (varStmt != null)
{
varStmts = varStmts ?? new WList <LNode>();
varStmts.Add(varStmt);
}
varStmt = node.With(S.Var, type, nameAndInit);
}
}
// Return a single statement or a list of them if necessary
if (varStmts != null)
{
varStmts.Add(varStmt);
return(F.Call(S.Splice, varStmts.ToVList()));
}
else
{
return(varStmt);
}
}
