single ir is briefly ok

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

@@ -277,6 +277,11 @@ namespace StgSharp.RegularAnalysis.Text
                 ir = ir_span[i];
                 if ((ir.Prefix.Mask & simple_alt) == simple_alt)
                 {
+                    if (TryGenerateSingleIR(outer_level, [ir], sc, code, local_func) > 0)
+                    {
+                        // TODO add additional code for the alt chain
+                    }
+
                     // simple match
                 } else if (ir is RegexTryIR _try && (ir.Prefix.Mask & simple_alt) == simple_alt)
                 {

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

@@ -5,7 +5,9 @@
 // SPDX-License-Identifier: MIT
 // -----------------------------------------------------------------------------
 
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 using StgSharp.RegularAnalysis.Abstraction;
+using System.Diagnostics.Metrics;
 using System.Globalization;
 using System.Text.RegularExpressions;
 
@@ -76,6 +78,25 @@ namespace StgSharp.RegularAnalysis.Text
 
         #region code
 
+        private static int TryGenerateSingleIR(
+                           int outer_level,
+                           ReadOnlySpan<RegexIR> ir_span,
+                           SourceGenContext sc,
+                           in SequenceEmitter<string> code,
+                           in List<SequenceEmitter<string>> local_func
+        )
+        {
+            return TryGenerateCountSeq(outer_level, ir_span, sc, code,
+                                       local_func) > 0 ||
+                   TryGenerateCountSet(outer_level, ir_span, sc, code,
+                                       local_func) > 0 ||
+                   TryGenerateMatchSet(outer_level, ir_span, sc, code,
+                                       local_func) > 0 ||
+                   TryGenerateMatchSeq(outer_level, ir_span, sc, code, local_func) > 0 ?
+                   1 :
+                   -1;
+        }
+
         private static int TryGeneratePack(
                            int outer_level,
                            ReadOnlySpan<RegexIR> ir_span,
@@ -203,6 +224,7 @@ namespace StgSharp.RegularAnalysis.Text
                     .AppendLine("}")
                     .AppendLine("else")
                     .AppendLine("{")//TODO fail here
+                    .AppendLine("break;")
                     .AppendLine("}");
             return 1;
         }
@@ -233,6 +255,10 @@ namespace StgSharp.RegularAnalysis.Text
              * {
              *     success here
              * }
+             * else
+             * {
+             *     fail case
+             * }
              */
             for (int i = 1; i < set_arr.Length - 1; i++)
             {
@@ -244,7 +270,11 @@ namespace StgSharp.RegularAnalysis.Text
             _case_code = GenLine(set, sc, ")");
             _ = code.AppendLine(_case_code)
                     .AppendLine("{")
-                    .AppendLine(sc.MakeRemainOffset(1))// TODO case success
+                    .AppendLine(sc.MakeRemainOffset(1))             // TODO case success
+                    .AppendLine("}")
+                    .AppendLine("else")
+                    .AppendLine("{")
+                    .AppendLine("break;")                                         // TODO case fail
                     .AppendLine("}");
             return 1;
         }

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

@@ -56,6 +56,21 @@ namespace StgSharp.RegularAnalysis.Text
 
             public string StepResult { get; } = _stepResult;
 
+            public string[] BeginRegion()
+            {
+                return [
+                    "do",
+                    "{"
+                    ];
+            }
+
+            public string[] CloseRegion()
+            {
+                return [
+                    "} while(true);"
+                    ];
+            }
+
             /// <summary>
             ///   Emits declarations for every slot requested during body generation.
             /// </summary>

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

@@ -91,7 +91,8 @@ namespace StgSharp.RegularAnalysis.Text
             brace_count = 0;
             foreach (string line in ce)
             {
-                bool is_right_brace = line == "}";
+                bool is_right_brace = (line == "}") ||
+                                      line.StartsWith("} while", StringComparison.InvariantCulture);
                 brace_count -= is_right_brace ? 1 : 0;
                 for (int i = 0; i < brace_count; i++) {
                     _ = code_source.Append("    ");