protected override ICode VisitDoLoop(StmtDoLoop s) {
var ctx = s.Ctx;
var body = (Stmt)this.Visit(s.Body);
var @while = (Expr)this.Visit(s.While);
var conditionVars = VisitorFindVars.V(@while);
var needAssigning = conditionVars.Except(this.stack.SelectMany(x => x), (IEqualityComparer<ExprVar>)this.phiComparer).ToArray();
if (needAssigning.Any()) {
var replacements = needAssigning.Select(x => {
var newExpr = ctx.Local(x.Type);
var phi = new ExprVarPhi(ctx) { Exprs = new[] { x, newExpr } };
return new { orgExpr = x, newExpr, phi };
}).ToArray();
foreach (var replace in replacements) {
this.stack.Peek().Add(replace.newExpr);
this.stack.Peek().Add(replace.phi);
@while = (Expr)VisitorReplace.V(@while, replace.orgExpr, replace.phi);
}
var assignmentStmts = replacements
.Select(x=>new StmtAssignment(ctx, x.newExpr, new ExprDefaultValue(ctx, x.newExpr.Type)))
.ToArray();
body = new StmtBlock(ctx, assignmentStmts.Concat(body));
}
if (body != s.Body || @while != s.While) {
return new StmtDoLoop(ctx, body, @while);
} else {
return s;
}
}
protected override ICode VisitContinuation(StmtContinuation s) {
// TODO: Why is this de-recursing blocks in continuations? Why doesn't it just derecurse itself (if possible)???
if (s.To.StmtType != Stmt.NodeType.Block) {
return base.VisitContinuation(s);
}
if (!this.seen.Add(s.To)) {
return base.VisitContinuation(s);
}
var block = (StmtBlock)s.To;
foreach (var stmt in block.Statements) {
if (stmt.StmtType == Stmt.NodeType.Continuation) {
// Continuation not inside 'if'
var sCont = (StmtContinuation)stmt;
if (sCont.To == block) {
// Recursive, so derecurse with no condition on loop
var body = new StmtBlock(s.Ctx, block.Statements.TakeWhile(x => x != stmt).ToArray());
var replaceWith = new StmtDoLoop(s.Ctx, body, new ExprLiteral(s.Ctx, true, s.Ctx.Boolean));
this.replaces.Add(s.To, replaceWith);
return base.VisitContinuation(s);
}
}
if (stmt.StmtType == Stmt.NodeType.If) {
// Continuation only statement within 'if' with only a 'then' clause
var sIf = (StmtIf)stmt;
if (sIf.Else == null && sIf.Then.StmtType == Stmt.NodeType.Continuation) {
var sThen = (StmtContinuation)sIf.Then;
if (sThen.To == block) {
// Recursive, so derecurse
var condition = sIf.Condition;
var bodyStmts = block.Statements.TakeWhile(x => x != stmt).ToArray();
var bodyLast = bodyStmts.LastOrDefault();
var body = new StmtBlock(s.Ctx, bodyStmts);
var loop = new StmtDoLoop(s.Ctx, body, condition);
var afterLoop = block.Statements.SkipWhile(x => x != stmt).Skip(1).ToArray();
if (VisitorFindContinuations.Get(new StmtBlock(s.Ctx, afterLoop)).Any(x => x.To == block)) {
// Cannot de-recurse yet, must wait for continuations to be merged
return base.VisitContinuation(s);
}
Stmt replaceWith;
if (afterLoop.Any()) {
var loopAndAfter = new[] { loop }.Concat(afterLoop).ToArray();
replaceWith = new StmtBlock(s.Ctx, loopAndAfter);
} else {
replaceWith = loop;
}
this.replaces.Add(s.To, replaceWith);
return base.VisitContinuation(s);
}
}
}
if (VisitorFindContinuations.Any(stmt)) {
// Another continuation present, cannot derecurse
break;
}
}
return base.VisitContinuation(s);
}
protected override ICode VisitDoLoop(StmtDoLoop s) {
var body = (Stmt)this.Visit(s.Body);
if (body == null) {
// Loop has no body
return null;
}
if (s.While.IsLiteralBoolean(false)) {
// Will never loop
return body;
}
if (body != s.Body) {
return new StmtDoLoop(s.Ctx, body, s.While);
} else {
return s;
}
}
protected override ICode VisitDoLoop(StmtDoLoop s) {
var body = (Stmt)this.Visit(s.Body);
StmtIf lastIf = null;
IEnumerable<Stmt> preIf = null;
if (body.StmtType == Stmt.NodeType.Block) {
var sBlock = (StmtBlock)body;
if (sBlock.Statements.Any()) {
var sLast = sBlock.Statements.Last();
if (sLast.StmtType == Stmt.NodeType.If) {
lastIf = (StmtIf)sLast;
preIf = sBlock.Statements.Take(sBlock.Statements.Count() - 1).ToArray();
}
}
} else if (body.StmtType == Stmt.NodeType.If) {
lastIf = (StmtIf)body;
preIf = Enumerable.Empty<Stmt>();
}
if (lastIf != null) {
Stmt afterLoop = null;
StmtIf newIf = null;
// See if final 'if' condition is same as the 'do' condition.
// TODO: This may lead to a non-terminating situation...
if (lastIf.Condition.DoesEqual(s.While)) {
afterLoop = lastIf.Else;
newIf = new StmtIf(s.Ctx, lastIf.Condition, lastIf.Then, null);
} else if (lastIf.Condition.DoesEqualNot(s.While)) {
afterLoop = lastIf.Then;
newIf = new StmtIf(s.Ctx, lastIf.Condition, null, lastIf.Else);
}
if (afterLoop != null) {
var loopBody = new StmtBlock(s.Ctx, preIf.Concat(newIf));
var loop = new StmtDoLoop(s.Ctx, loopBody, s.While);
var ret = new StmtBlock(s.Ctx, loop, afterLoop);
return ret;
}
}
if (body != s.Body) {
return new StmtDoLoop(s.Ctx, body, s.While);
} else {
return s;
}
}
protected override ICode VisitDoLoop(StmtDoLoop s) {
this.NewLine();
this.js.Append("do {");
this.indent++;
this.Visit(s.Body);
this.indent--;
this.NewLine();
this.js.Append("} while (");
this.Visit(s.While);
this.js.Append(");");
return s;
}
protected override ICode VisitDoLoop(StmtDoLoop s) {
return this.Isolate(() => base.VisitDoLoop(s));
}