Merge pull request #17 from linq2db/issues_15_16

Release 2.5.2 candidate

Source/CSharpTools.cs

@@ -0,0 +1,167 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Text;
+
+namespace LinqToDB.LINQPad
+{
+	// added temporary from https://github.com/linq2db/linq2db/pull/1393
+	internal static class CSharpTools
+	{
+		/// <summary>
+		/// Reserved words taken from
+		/// <see href="https://msdn.microsoft.com/en-us/library/x53a06bb%28v=vs.140%29.aspx"/>.
+		/// List actual for C# 7.3.
+		/// Doesn't contain "using static",
+		/// </summary>
+		private static readonly ISet<string> _reservedWords
+			= new HashSet<string>()
+		{
+			"abstract",  "as",         "base",      "bool",     "break",    "byte",      "case",    "catch",
+			"char",      "checked",    "class",     "const",    "continue", "decimal",   "default", "delegate",
+			"do",        "double",     "else",      "enum",     "event",    "explicit",  "extern",  "false",
+			"finally",   "fixed",      "float",     "for",      "foreach",  "goto",      "if",      "implicit",
+			"in",        "int",        "interface", "internal", "is",       "lock",      "long",    "namespace",
+			"new",       "null",       "object",    "operator", "out",      "override",  "params",  "private",
+			"protected", "public",     "readonly",  "ref",      "return",   "sbyte",     "sealed",  "short",
+			"sizeof",    "stackalloc", "static",    "string",   "struct",   "switch",    "this",    "throw",
+			"true",      "try",        "typeof",    "uint",     "ulong",    "unchecked", "unsafe",  "ushort",
+			"using",     "virtual",    "void",      "volatile", "while"
+		};
+
+		/// <summary>
+		/// Contextual words taken from
+		/// <see href="https://msdn.microsoft.com/en-us/library/x53a06bb%28v=vs.140%29.aspx"/>.
+		/// List actual for C# 7.3.
+		/// </summary>
+		private static readonly ISet<string> _contextualWords
+			= new HashSet<string>()
+		{
+			"add",    "alias", "ascending", "async",   "await",  "by",     "descending", "dynamic",
+			"equals", "from",  "get",       "global",  "group",  "into",   "join",       "let",
+			"nameof", "on",    "orderby",   "partial", "remove", "select", "set",        "unmanaged",
+			"value",  "var",   "when",      "where",   "yield"
+		};
+
+		private static readonly ISet<UnicodeCategory> _otherCharsCategories;
+
+		private static readonly ISet<UnicodeCategory> _startCharCategories;
+
+		static CSharpTools()
+		{
+			_startCharCategories = new HashSet<UnicodeCategory>()
+			{
+				// Lu letter
+				UnicodeCategory.UppercaseLetter,
+				// Ll letter
+				UnicodeCategory.LowercaseLetter,
+				// Lt letter
+				UnicodeCategory.TitlecaseLetter,
+				// Lm letter
+				UnicodeCategory.ModifierLetter,
+				// Lo letter
+				UnicodeCategory.OtherLetter,
+				// Nl letter
+				UnicodeCategory.LetterNumber
+			};
+
+			_otherCharsCategories = new HashSet<UnicodeCategory>(_startCharCategories)
+			{
+				// Mn
+				UnicodeCategory.NonSpacingMark,
+				// Mc
+				UnicodeCategory.SpacingCombiningMark,
+				// Nd
+				UnicodeCategory.DecimalDigitNumber,
+				// Pc
+				UnicodeCategory.ConnectorPunctuation,
+				// Cf
+				UnicodeCategory.Format
+			};
+		}
+
+		/// <summary>
+		/// Converts <paramref name="name"/> to valid C# identifier.
+		/// </summary>
+		public static string ToValidIdentifier(string name)
+		{
+			if (name == null || name == string.Empty || name == "@")
+			{
+				return "_";
+			}
+
+			if (_reservedWords.Contains(name) || _contextualWords.Contains(name))
+			{
+				return "@" + name;
+			}
+
+			if (name.StartsWith("@"))
+			{
+				if (_reservedWords.Contains(name.Substring(1)) || _contextualWords.Contains(name.Substring(1)))
+				{
+					return name;
+				}
+				else
+				{
+					name = name.Substring(1);
+				}
+			}
+
+			var sb = new StringBuilder();
+
+			foreach (var chr in name)
+			{
+				var cat = CharUnicodeInfo.GetUnicodeCategory(chr);
+				if (sb.Length == 0 && !_startCharCategories.Contains(cat) && chr != '_')
+				{
+					sb.Append("_");
+				}
+
+				if (sb.Length != 0 && !_otherCharsCategories.Contains(cat))
+				{
+					sb.Append("_");
+				}
+				else
+				{
+					sb.Append(chr);
+				}
+			}
+
+			if (sb.Length >= 2 && sb[0] == '_' && sb[1] == '_' && (sb.Length == 2 || sb[2] != '_'))
+			{
+				sb.Insert(0, '_');
+			}
+
+			return sb.ToString();
+		}
+
+		public static string ToStringLiteral(string value)
+		{
+			if (value == null)
+				return "null";
+
+			var sb = new StringBuilder("\"");
+
+			foreach (var chr in value)
+			{
+				switch (chr)
+				{
+					case '\t': sb.Append("\\t"); break;
+					case '\n': sb.Append("\\n"); break;
+					case '\r': sb.Append("\\r"); break;
+					case '\\': sb.Append("\\\\"); break;
+					case '"': sb.Append("\\\""); break;
+					case '\0': sb.Append("\\0"); break;
+					case '\u0085':
+					case '\u2028':
+					case '\u2029':
+						sb.Append($"\\u{(ushort)chr:X4}"); break;
+					default: sb.Append(chr); break;
+				}
+			}
+
+			sb.Append('"');
+
+			return sb.ToString();
+		}
+	}
+}