Json Prettifier and Minifier

JsonPrettifier.cs

public static string Prettify(string json)
{
    var sb = new StringBuilder(json.Length * 2);
    var indent = 0;
    var startOfLine = false;
    for (var i = 0; i < json.Length; ++i)
    {
        var c = json[i];
        if (!char.IsWhiteSpace(c))
        {
            var nextIsStartOfLine = false;
            switch (c)
            {
                case '}':
                case ']':
                    --indent;
                    startOfLine = true;
                    nextIsStartOfLine = true;
                    break;
                case ',':
                    startOfLine = false;
                    nextIsStartOfLine = true;
                    break;
            }
            if (startOfLine)
            {
                sb.AppendLine()
                  .Append(' ', Math.Max(indent * 2, 0));
                startOfLine = false;
            }
            sb.Append(c);
            switch (c)
            {
                case '{':
                case '[':
                    ++indent;
                    startOfLine = true;
                    break;
                case '\"':
                    c = '_'; // throw-away value
                    var escape = false;
                    while (i + 1 < json.Length && (escape || c != '\"'))
                    {
                        escape = c == '\\' ? !escape : false;
                        sb.Append(c = json[++i]);
                    }
                    break;
                case ':':
                    sb.Append(' ');
                    break;
                default:
                    startOfLine = nextIsStartOfLine;
                    break;
            }
        }
    }
    return sb.ToString();
}

public static string Minify(string json)
{
    var sb = new StringBuilder(json.Length);
    for (var i = 0; i < json.Length; ++i)
    {
        var c = json[i];
        if (!char.IsWhiteSpace(c))
        {
            sb.Append(c);
            if (c == '\"')
            {
                c = '_'; // throw-away value
                var escape = false;
                while (i + 1 < json.Length && (escape || c != '\"'))
                {
                    escape = c == '\\' ? !escape : false;
                    sb.Append(c = json[++i]);
                }
            }
        }
    }
    return sb.ToString();
}