示例#1
0
        public override Block CompileNewState(Runtime runtime, StateForCompiler state)
        {
            ParserBlock block = new ParserBlock();

            block.Comment("begin precedence alt -----------");

            // todo enter

            block.BeginScope();

            BlockLabel returnLabel = new BlockLabel("return");

            BlockLocal oldLeftRecursiveAlts = new BlockLocal(typeof(IParseable));

            block.DeclareLocal(oldLeftRecursiveAlts);
            block.LoadState();
            block.GetProperty(typeof(ParserState).GetProperty("LeftRecursiveAlts"));
            block.StoreLocal(oldLeftRecursiveAlts);

            ParseGraphNode oldLeftRecursiveAltsForCompiler = state.LeftRecursiveAlts;

            foreach (PrecedenceAltGroup group in groups)
            {
                block.BeginScope();

                BlockLocal groupLocal = new BlockLocal(typeof(PrecedenceAltGroup));
                block.DeclareLocal(groupLocal);
                block.Load(group);
                block.StoreLocal(groupLocal);

                BlockLabel apply         = new BlockLabel("apply");
                BlockLabel continueLabel = new BlockLabel("continue");

                BlockLocal currentPrecedence = new BlockLocal(typeof(Precedence));
                block.DeclareLocal(currentPrecedence);
                block.LoadState();
                block.GetProperty(typeof(ParserState).GetProperty("CurrentPrecedence"));
                block.Dup();
                block.StoreLocal(currentPrecedence);
                block.BranchIfNull(apply);

                BlockLocal groupPrecedence = new BlockLocal(typeof(Precedence));
                block.DeclareLocal(groupPrecedence);
                block.LoadLocal(groupLocal);
                block.GetProperty(groupLocal.Type.GetProperty("Precedence"));
                block.Dup();
                block.StoreLocal(groupPrecedence);
                block.BranchIfNull(apply);

                block.LoadLocal(currentPrecedence);
                block.GetProperty(currentPrecedence.Type.GetProperty("Group"));
                block.LoadLocal(groupPrecedence);
                block.GetProperty(groupPrecedence.Type.GetProperty("Group"));
                block.BranchIfNotEqual(apply);

                block.LoadLocal(groupPrecedence);
                block.LoadLocal(currentPrecedence);
                block.LoadState();
                block.GetProperty(typeof(ParserState).GetProperty("PrecedenceCanEqualCurrent"));
                block.LogicalNot();
                block.Call(groupPrecedence.Type.GetMethod("IsLowerThan"));
                block.BranchIfTrue(continueLabel);

                block.MarkLabel(apply);

                block.LoadState();
                block.LoadLocal(groupLocal);
                block.GetProperty(groupLocal.Type.GetProperty("LeftRecursiveParseGraph"));
                block.SetProperty(typeof(ParserState).GetProperty("LeftRecursiveAlts"));

                state.LeftRecursiveAlts = group.LeftRecursiveParseGraph;

                block.Emit(group.ParseGraph.Compile(runtime, state));

                block.Dup();

                BlockLabel no = new BlockLabel("no");
                block.BranchIfNo(no);

                block.LoadState();
                block.LoadLocal(oldLeftRecursiveAlts);
                block.SetProperty(typeof(ParserState).GetProperty("LeftRecursiveAlts"));

                // todo yes

                block.Branch(returnLabel);

                block.MarkLabel(no);

                block.Pop();

                block.MarkLabel(continueLabel);

                block.EndScope();
            }

            block.LoadState();
            block.LoadLocal(oldLeftRecursiveAlts);
            block.SetProperty(typeof(ParserState).GetProperty("LeftRecursiveAlts"));

            state.LeftRecursiveAlts = oldLeftRecursiveAltsForCompiler;

            block.EndScope();

            // todo no

            block.LoadNo();

            block.MarkLabel(returnLabel);

            block.Comment("end precedence alt -----------");

            return(block);
        }