mainly theoratical work

src/StgSharp.RegularAnalysis/Text/TextRegex.cs

@@ -7,7 +7,9 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
+using System.Runtime.CompilerServices;
 using System.Text;
 using System.Threading.Tasks;
 
@@ -16,10 +18,125 @@ namespace StgSharp.RegularAnalysis.Text
     public abstract class TextRegex
     {
 
+        private const int WordCategoriesMask =
+    1 << (int)UnicodeCategory.UppercaseLetter | (1 << (int)UnicodeCategory.LowercaseLetter) | (1 << (int)UnicodeCategory.TitlecaseLetter) | 1 << (int)UnicodeCategory.ModifierLetter | 1 << (int)UnicodeCategory.OtherLetter | 1 << (int)UnicodeCategory.NonSpacingMark | 1 << (int)UnicodeCategory.DecimalDigitNumber | 1 << (int)UnicodeCategory.ConnectorPunctuation;
+
         public abstract MatchResult Match(
                                     ReadOnlySpan<char> text
         );
 
+        #region is char a word
+
+        /*
+         * Semantic reference:
+         *
+         *   .NET regular-expression word character: \w
+         *
+         * A character is treated as a word character when its Unicode general
+         * category is one of:
+         *
+         *   Lu  UppercaseLetter
+         *   Ll  LowercaseLetter
+         *   Lt  TitlecaseLetter
+         *   Lm  ModifierLetter
+         *   Lo  OtherLetter
+         *   Mn  NonSpacingMark
+         *   Nd  DecimalDigitNumber
+         *   Pc  ConnectorPunctuation
+         *
+         * The behavior and the ASCII-fast-path design are based on:
+         *
+         *   dotnet/runtime
+         *   System.Text.RegularExpressions.RegexCharClass.IsWordChar
+         *
+         * Source:
+         * https://github.com/dotnet/runtime/blob/main/src/libraries/
+         * System.Text.RegularExpressions/src/System/Text/RegularExpressions/
+         * RegexCharClass.cs
+         *
+         * dotnet/runtime is licensed under the MIT License.
+         *
+         * This implementation is written for NGRA rather than copied verbatim,
+         * but the source is recorded here because its intended semantics are
+         * explicitly compatible with .NET Regex.
+         */
+
+        /// <summary>
+        ///   Bit mask containing every Unicode general category accepted by the default .NET
+        ///   regular-expression <c> \w </c> character class.
+        /// </summary>
+        /// <remarks>
+        ///   <see cref="UnicodeCategory" /> values are small integer identifiers, so each category
+        ///   can be represented by one bit.
+        /// </remarks>
+        private const uint WordCategoryMask =
+            (1u << (int)UnicodeCategory.UppercaseLetter) | (1u << (int)UnicodeCategory.LowercaseLetter) | (1u << (int)UnicodeCategory.TitlecaseLetter) | (1u << (int)UnicodeCategory.ModifierLetter) | (1u << (int)UnicodeCategory.OtherLetter) | (1u << (int)UnicodeCategory.NonSpacingMark) | (1u << (int)UnicodeCategory.DecimalDigitNumber) | (1u << (int)UnicodeCategory.ConnectorPunctuation);
+
+        /// <summary>
+        ///   Determines whether one UTF-16 code unit belongs to the default .NET regular-expression
+        ///   <c> \w </c> character class.
+        /// </summary>
+        /// <param name="value">
+        ///   The UTF-16 code unit to classify.
+        /// </param>
+        /// <returns>
+        ///   <see langword="true" /> when <paramref name="value" /> is a word character; otherwise,
+        ///   <see langword="false" />.
+        /// </returns>
+        /// <remarks>
+        ///   <para>/// This method operates on a single <see cref="char" />, and therefore /// on a
+        ///   single UTF-16 code unit rather than on a complete Unicode scalar /// value. ///
+        ///   </para> <para>/// Characters in the Unicode Basic Multilingual Plane are classified
+        ///   /// normally. A supplementary-plane character is represented by a /// surrogate pair
+        ///   and is therefore presented to this method as two /// separate surrogate code units.
+        ///   Neither surrogate is independently /// treated as a word character. This follows the
+        ///   char-based behavior of /// the corresponding .NET Regex helper. /// </para> <para>///
+        ///   For ASCII input, the Unicode-category lookup is avoided. In ASCII, /// the accepted
+        ///   set is exactly: /// <c> [A-Za-z0-9_] </c>. /// </para> <para>/// This method
+        ///   implements ordinary .NET <c> \w </c> semantics. It does /// not implement the ASCII-
+        ///   oriented behavior enabled by /// <c> RegexOptions.ECMAScript </c>. /// </para>
+        /// </remarks>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        protected static bool IsCharWord(
+                              char value
+        )
+        {
+            /*
+             * ASCII fast path.
+             *
+             * Unsigned subtraction combines the lower-bound and upper-bound
+             * checks into one comparison:
+             *
+             *   value in ['A', 'Z']
+             *       => value - 'A' is in [0, 25]
+             *
+             * Values below 'A' underflow after conversion to uint and therefore
+             * also fail the comparison.
+             */
+            if (value <= '\x7F')
+            {
+                return
+                    (uint)(value - 'A') <= 'Z' - 'A' ||
+                    (uint)(value - 'a') <= 'z' - 'a' ||
+                    (uint)(value - '0') <= '9' - '0' ||
+                    value == '_';
+            }
+
+            /*
+             * Non-ASCII path.
+             *
+             * CharUnicodeInfo classifies the current UTF-16 code unit using
+             * Unicode general categories. The resulting category selects one
+             * bit from WordCategoryMask.
+             */
+            UnicodeCategory category =
+                CharUnicodeInfo.GetUnicodeCategory(value);
+
+            return
+                (WordCategoryMask & (1u << (int)category)) != 0;
+        }
+
+        #endregion
     }
 
     public ref struct MatchResult { }

src/StgSharp.RegularAnalysis/Text/TextRegexSourceGen.GenClass.cs

@@ -5,6 +5,7 @@
 // SPDX-License-Identifier: MIT
 // -----------------------------------------------------------------------------
 
+using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
 using StgSharp.RegularAnalysis.Abstraction;
 using System;
@@ -90,6 +91,20 @@ namespace StgSharp.RegularAnalysis.Text
             return se;
         }
 
+        private static string FormatStringLiteral(
+                              string str
+        )
+        {
+            return SyntaxFactory.Literal(str).Text;
+        }
+
+        private static string FormatStringLiteral(
+                              char str
+        )
+        {
+            return SyntaxFactory.Literal(str).Text;
+        }
+
         #region sub generator
 
         private static int TryGenerateFindSeq(
@@ -122,7 +137,7 @@ namespace StgSharp.RegularAnalysis.Text
             if (scan_win[0] is not RegexFindSeqIR seq) {
                 return -1;
             }
-            string pattern = seq.Pattern;
+            string pattern = FormatStringLiteral(seq.Pattern);
             int length = pattern.Length;
 
             _ = se.AppendLine()
@@ -189,13 +204,14 @@ namespace StgSharp.RegularAnalysis.Text
                 {
                     // Handle single character
                     case CharSetType.Single:
+                        string literal = FormatStringLiteral(c.Value);
                         caller = first ? "IndexOfAny" : "LastIndexOfAny";
-                        return $@"({offset} = {remain}.{caller}(""{c.Value}"") != -1)";
+                        return $@"({offset} = {remain}.{caller}(""{literal}"") != -1)";
 
                     // Handle range of characters
                     case CharSetType.Range:
                         caller = first ? "IndexOfAnyInRange" : "LastIndexOfAnyInRange";
-                        return $@"({offset} = {remain}.{caller}('{c.Value[0]}', '{c.Value[1]}') != -1)";
+                        return $@"({offset} = {remain}.{caller}('{FormatStringLiteral(c.Value[0])}', '{FormatStringLiteral(c.Value[1])}') != -1)";
 
                     // Handle set of characters
                     case CharSetType.Set: