tm.js

// Statesクラスのようなもの
function States() {
    this.stateNames = [];
}
// states.状態名.nextState[i]
// states.状態名.readSymbol[i]
// states.状態名.writeSymbol[i]
// states.状態名.direction directionだけは状態に固有の値
States.prototype.push = function (addingState, nextState, readSymbol, writeSymbol, direction) {
    if (this.stateNames.indexOf(addingState) == -1) {
        this.stateNames.push(addingState);
        eval("states." + addingState + " = new Object();");
        eval("states." + addingState + ".nextState = [];");
        eval("states." + addingState + ".readSymbol = [];");
        eval("states." + addingState + ".writeSymbol = [];");
        eval("states." + addingState + ".nextState.push(\"" + nextState + "\");");
        eval("states." + addingState + ".readSymbol.push(\"" + readSymbol + "\");");
        eval("states." + addingState + ".writeSymbol.push(\"" + writeSymbol + "\");");
        eval("states." + addingState + ".direction = \"" + direction + "\";");
    } else {
        eval("states." + addingState + ".nextState.push(\"" + nextState + "\");");
        eval("states." + addingState + ".readSymbol.push(\"" + readSymbol + "\");");
        eval("states." + addingState + ".writeSymbol.push(\"" + writeSymbol + "\");");
    }
}


function initialize() {
    tape = [];
    states = new States();
    currentState = "";
    $(".result").text("");
    $("tr").remove();
}


function readFile() {
    var fileObj = $("#input").prop("files")[0];
    var reader = new FileReader();
    reader.onload = function(e) {
        var TMDescription = reader.result;
        var rows = TMDescription.split(/\r\n|\r|\n/);
        var units;
        for (var i = 0; i < rows.length; i++) {
            units = rows[i].split(/\,/);
            /****************************
             **********  注意  **********
             ****************************/
            if (units.length == 5) {
                if (states.stateNames.length == 0) {
                    currentState = units[0]; // 一番最初に取得した状態を開始状態とする
                }
                states.push(units[0], units[1], units[2], units[3], units[4]);
            }
        }
        states.push("reject", "-", "-", "-", "-");
        states.push("accept", "-", "-", "-", "-");

        // ファイル読み込みが並列で行われてるらしく，
        // 読み込みが終わる前に処理がどんどん進んでしまってバグの原因になっていた．
        // 本当はmainに上手いこと書くべきなのだろうが，
        // 思いつかないのでとりあえずはここに置いておく．
        readTape();
        runTuringMachine();
    };
    reader.readAsText(fileObj, "UTF-8");
}


function readTape() {
    var tapeDescription = $("#tape").val();
    tape = tapeDescription.split(/\,/);
    for (var i = 0; i < tape.length; i++) {
        if (tape[i] == " ") {
            tape[i] = "_";
        }
    }
}


function appendCurrentTapeToTable(transitionCount, headIndex) {
    $("tbody").append("<tr></tr>");
    $("tr:last").append("<th>" + transitionCount + "(" + currentState + ")</th>");
    for (var i = 0; i < tape.length; i++) {
        $("tr:last").append("<td>" + tape[i] + "</td>");
        if (i == headIndex) {
            $("td:last").attr("id", "head");
        }
    }
}


function runTuringMachine() {
    var maximumTransitionCount = $("input[name=max]").val();
    var j = 0, headIndex = 0, isTapeExtended = false;
    eval("var obj = states." + currentState + ";");
    for (var i = 0; i < maximumTransitionCount; i++) {
        if (currentState == "accept") {
            $(".result").text("受理");
            break;
        } else if (currentState == "reject") {
            $(".result").text("非受理");
            break;
        }

        if (obj.direction == "R") {
            Outer:
            for (headIndex++;; headIndex++) {
                if (headIndex >= tape.length) {
                    if (isTapeExtended) {
                        alert("テープの内容を確認して下さい．");
                        return;
                    }
                    tape[headIndex] = "_"; // 右側はスペース
                    isTapeExtended = true;
                }
                for (j = 0; j < obj.readSymbol.length; j++) {
                    if (tape[headIndex] == obj.readSymbol[j]) {
                        isTapeExtended = false;
                        break Outer;
                    }
                }
            }
        } else if (obj.direction == "L") {
            Outer:
            for (headIndex--;; headIndex--) {
                for (j = 0; j < obj.readSymbol.length; j++) {
                    if (tape[headIndex] == obj.readSymbol[j]) {
                        break Outer;
                    }
                }
            }
        } else {
            for (j = 0; j < obj.readSymbol.length; j++) {
                if (tape[headIndex] == obj.readSymbol[j]) {
                    break;
                }
            }
        }

        appendCurrentTapeToTable(i + 1, headIndex);

        tape[headIndex] = obj.writeSymbol[j];
        eval("currentState = states." + currentState + ".nextState[" + j + "];");
        eval("obj = states." + currentState + ";");
    }

    appendCurrentTapeToTable(i + 1, headIndex);
    $("tbody").prepend("<tr><th></th></tr>");
    for (var i = 0; i < tape.length; i++) {
        $("tr:first").append("<th>" + (i + 1) + "</th>");
    }
}


$(function() {
    $("#run").click(function() {
        initialize();
        readFile();
    });
})