firstFollow/index.html at master · BrunoRB/firstFollow · GitHub

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<!DOCTYPE html lang="en">
<html>
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <title>first-follow</title>
        <meta name="description" content="Simple first and follow sets generator for context-free grammars">
        <style>
        body {
            font-size: large;
        }
        header {
            margin: 1%;
            margin-bottom: 2%;
        }

        #run-grammar {
            padding: 10px;
            cursor: pointer;
            font-size: medium;
        }

        textarea, table {
            font-size: large;
        }

        table caption {
            font-weight: bold;
        }

        table {
            border-collapse: collapse;
            margin: 10px;
            margin-top: 35px;
            display: inline-block;
        }

        th, td {
            border: 1px solid black;
        }

        table td, table th {
            padding: 10px;
        }

        @media (min-width: 1000px) {
            #rules {
                float: right;
                max-width: 30%;
                margin-right: 3%;
                top: 0px;
                margin-top: 0px;
            }
            #left {
                float: left;
                max-width: 60%;
                margin-left: 3%;
            }
        }
        h1 { display: inline;}
        </style>
    </head>
    <body>
        <header>
            <h1>firstFollow</h1>
            <a id="github" href="https://github.com/BrunoRB/firstFollow" title="Got to repository page">
                <img src="GitHub-Mark-32px.png" />
            </a>
            <p>Simple <strong>first and follow sets</strong> generator for context-free grammars.</p>
        </header>
        <div>
            <aside id="rules">
                <h2>Accepted input</h2>
                <ul>
                 <li>Nonterminals should be separated from their derivations by -> or →, ex:
                     <ul>
                        <li>A -> B</li>
                        <li>B → y</li>
                    </ul>
                </li>
                <li>Multiple symbols should be separated by blank spaces, ex:
                    <ul>
                        <li>X → yOne yTwo y3</li>
                        <li>yTwo → W thisIsConsideredAsingleSymbol</li>
                        <li>W → those are considered five symbols</li>
                    </ul>
                </li>
                <li>Each set of rules must be in a newline and must not break into a new
                    line, or optionally multiple sets of rules can be placed at same line as long as all of them,
                    with the exception of the last one, are terminated by a semicolon (;), ex:
                    <ul>
                        <li>A → y w B</li>
                        <li>B → C y; C → w</li>
                    </ul>
                </li>
                <li>
                    Multiple derivations can be stated in the same line using the "|" separator:
                    <ul>
                        <li>A → w y | k | f</li>
                    </ul>
                </li>
                <li>For Epsilon derivations use ε, ϵ or leave the derivation empty:
                    <ul>
                        <li>A → B | ε</li>
                        <li>B → | K</li>
                        <li>B → j | ϵ</li>
                        <li>K →</li>
                    </ul>
                </li>
            </aside>
            <div id="left">
                <label for="grammar">
                    Your grammar:
                </label> <br>
                    <textarea id="grammar" rows="15" cols=60 placeholder="A -> k y x B

B -> | k"></textarea>
                <br>
                <button id="run-grammar" type="button">Generate</button>

                <div id="parse-error"></div>

                <table id="first-table" style="visibility: hidden;">
                    <caption>First sets</caption>
                    <thead>
                        <tr>
                            <th>Symbol</th>
                            <th>Set</th>
                        </tr>
                    </thead>
                    <tbody></tbody>
                </table>
                <table id="follow-table" style="visibility: hidden;" tabindex="-1">
                    <caption>Follow sets</caption>
                    <thead>
                        <tr>
                            <th>Symbol</th>
                            <th>Set</th>
                        </tr>
                    </thead>
                    <tbody></tbody>
                </table>
            </div>
        </div>
        <script src="src/main.js"></script>
        <script>
(function() {
    'use strict';
    var hasStorage = typeof localStorage !== 'undefined';
    var parseError = document.getElementById('parse-error');
    var textarea = document.getElementById('grammar');
    var firstTable = document.getElementById('first-table');
    var followTable = document.getElementById('follow-table');
    var firstTbody = document.querySelector('#first-table tbody');
    var followTbody = document.querySelector('#follow-table tbody');

    document.getElementById('run-grammar').addEventListener('click', function() {
        var grammar = textarea.value.trim();
        try {
            var data = firstFollow(grammar);
        }
        catch(e) {
            firstTable.style.visibility = 'hidden';
            followTable.style.visibility = 'hidden';
            parseError.innerHTML = 'Error: ' + e;
            return;
        }

        parseError.innerHTML = '';

        var firstSet = data.firstSet;
        var followSet = data.followSet;

        var fContent = [];
        var foContent = [];
        for (var symbol in firstSet) {
            var flist = Object.keys(firstSet[symbol]).map(function(s) {
                return s === '' ? 'ε' : s;
            });
            fContent.push(
                '<tr><td>' + symbol + '</td><td>{' + flist.join(', ') + '}</td></tr>'
            );
        }
        for (var symbol in followSet) {
            foContent.push(
                '<tr><td>' + symbol + '</td><td>{' + Object.keys(followSet[symbol]).join(', ') + '}</td></tr>'
            );
        }

        firstTbody.innerHTML = fContent.join('');
        followTbody.innerHTML = foContent.join('');

        firstTable.style.visibility = 'visible';
        followTable.style.visibility = 'visible';
        followTable.focus();

        if (hasStorage) {
            localStorage.setItem('data', grammar);
        }
    }, false);

    if (hasStorage) {
        var grammar = localStorage.getItem('data');
        if (grammar) {
            textarea.value = grammar;
        }
    }
})();
        </script>
    </body>
</html>