ReCode 1.1.0

ReCode

The Fast Regular Expression compiler for C#.

Introduction

Inspired by RE2C, this library can be referenced from a T4 text template for the purpose of generating code for parallel matching of a block of regular expressions.

Supported inputs for matching are pointers to a sequence of bytes or chars. This enables generation of fast scanners/tokenizers for almost any purpose (even binary data).

Usage

ReCode is enabled in a text template by referencing the dll:

<#@ assembly name="$(SolutionDir)packages\\ReCode.1.0.3\\lib\\452\\ReCode.dll" #>
<#@ import namespace="ReCode" #>

Example

As an example of a compiled block of expressions, consider the following example:

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="$(SolutionDir)packages\\ReCode.1.0.3\\lib\\452\\ReCode.dll" #>
<#@ import namespace="ReCode" #>
<#@ output extension=".cs" #>
using System.Collections.Generic;

namespace ReCodeTest {
    public class TestParser2 {
        public static unsafe KeyValuePair<ushort, int>? Parse(char * start, int len){
            var pNext = start;
            var pLimit = start + len;
            var pEnd = start; 
<#
foreach(var token in ReCode.RegularExpressionTokens(WriteLine)) {
    for(var i=0;i<10;i++)
      if(token.Matches($"'{25*i}'"))                            { #> return new KeyValuePair<ushort,int>(<#=i#>, (int)(pEnd - start)); <#}
    if(token.Matches(@"[+\-]?[0-9]*[\.][0-9]+[E][+\-]?[0-9]+")) { #> return new KeyValuePair<ushort,int>(10, (int)(pEnd - start)); <# }
    if(token.Matches(@"[+\-]?[0-9]*[\.][0-9]+"))                { #> return new KeyValuePair<ushort,int>(11, (int)(pEnd - start)); <# }
    if(token.Matches(@"[+\-]?[0-9]+"))                          { #> return new KeyValuePair<ushort,int>(12, (int)(pEnd - start)); <# }
    if(token.Fails)                                             { #> return null; <# }
}
#>
        }
    }
}

The resulting function matches the following sequences

• 0 maps to 0
• 25 maps to 1
• 50 maps to 2
• 75 maps to 3
• 100 maps to 4
• 125 maps to 5
• 150 maps to 6
• 175 maps to 7
• 200 maps to 8
• 225 maps to 9
• [+\-]?[0-9]*[\.][0-9]+[E][+\-]?[0-9]+ maps to 10
• [+\-]?[0-9]*[\.][0-9]+ maps to 11
• [+\-]?[0-9]+ maps to 12

The block is executed with semantics corresponding to executing the expressions one by one in the listed order until a match is reached. If nothing was matched, the token.Fails block is executed.

Internal Scanning and Parsing

ReCode internally uses a pre-compiled version of ReCode for constructing the scanner for the regular expression syntax.

The library also contains logic for constructing LR(1) grammar parsers from a T4 template. This logic is used for parsing the regular expression patterns. This part of the library seems to work very well, but has not been extensively tested.

Generated Code

The resulting code executes a deterministic finite automaton (DFA) for recognizing the supplied regular expressions (with documentation).

As of version 1, the generated code for the above example would be the following:

using System.Collections.Generic;

namespace ReCodeTest {
	public class TestParser2 {
		public static unsafe KeyValuePair<ushort, int>? Parse(char * start, int len){
            var pNext = start;
            var pLimit = start + len;
            var pEnd = start; 
{
/*
 * Union
 *  +-Accept(0)
 *  |  +-Sequence(CaseInsensitive,'0')
 *  +-Accept(1)
 *  |  +-Sequence(CaseInsensitive,'25')
 *  +-Accept(2)
 *  |  +-Sequence(CaseInsensitive,'50')
 *  +-Accept(3)
 *  |  +-Sequence(CaseInsensitive,'75')
 *  +-Accept(4)
 *  |  +-Sequence(CaseInsensitive,'100')
 *  +-Accept(5)
 *  |  +-Sequence(CaseInsensitive,'125')
 *  +-Accept(6)
 *  |  +-Sequence(CaseInsensitive,'150')
 *  +-Accept(7)
 *  |  +-Sequence(CaseInsensitive,'175')
 *  +-Accept(8)
 *  |  +-Sequence(CaseInsensitive,'200')
 *  +-Accept(9)
 *  |  +-Sequence(CaseInsensitive,'225')
 *  +-Accept(10)
 *  |  +-Concat
 *  |     +-Repeat(ZeroOrOne)
 *  |     |  +-Ranges('+','-')
 *  |     +-Repeat(ZeroOrMore)
 *  |     |  +-Ranges(['0'-'9'])
 *  |     +-Ranges('.')
 *  |     +-Repeat(OneOrMore)
 *  |     |  +-Ranges(['0'-'9'])
 *  |     +-Ranges('E')
 *  |     +-Repeat(ZeroOrOne)
 *  |     |  +-Ranges('+','-')
 *  |     +-Repeat(OneOrMore)
 *  |        +-Ranges(['0'-'9'])
 *  +-Accept(11)
 *  |  +-Concat
 *  |     +-Repeat(ZeroOrOne)
 *  |     |  +-Ranges('+','-')
 *  |     +-Repeat(ZeroOrMore)
 *  |     |  +-Ranges(['0'-'9'])
 *  |     +-Ranges('.')
 *  |     +-Repeat(OneOrMore)
 *  |        +-Ranges(['0'-'9'])
 *  +-Accept(12)
 *     +-Concat
 *        +-Repeat(ZeroOrOne)
 *        |  +-Ranges('+','-')
 *        +-Repeat(OneOrMore)
 *           +-Ranges(['0'-'9'])
 */
/*
 * DFA STATE 0
 * '+' -> 1
 * '-' -> 1
 * '.' -> 2
 * '0' -> 3
 * '1' -> 4
 * '2' -> 5
 * ['3'-'4'] -> 6
 * '5' -> 7
 * '6' -> 6
 * '7' -> 8
 * ['8'-'9'] -> 6
 */
if(pNext >= pLimit) goto nonaccept0;
var current = *pNext++;
if(current < 0x31) /* ('0') '1' */  {
    if(current < 0x2D) /* (',') '-' */  {
        if(current < 0x2B) /* ('*') '+' */ 
            goto nonaccept0;
        if(current < 0x2C) /* ('+') ',' */ 
            goto state0_1;
        goto nonaccept0;
    }
    if(current < 0x2F) /* ('.') '/' */  {
        if(current < 0x2E) /* ('-') '.' */ 
            goto state0_1;
        goto state0_2;
    }
    if(current < 0x30) /* ('/') '0' */ 
        goto nonaccept0;
    goto state0_3;
}
if(current < 0x36) /* ('5') '6' */  {
    if(current < 0x33) /* ('2') '3' */  {
        if(current < 0x32) /* ('1') '2' */ 
            goto state0_4;
        goto state0_5;
    }
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    goto state0_7;
}
if(current < 0x38) /* ('7') '8' */  {
    if(current < 0x37) /* ('6') '7' */ 
        goto state0_6;
    goto state0_8;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto nonaccept0;
/*
 * DFA STATE 1
 * '.' -> 2
 * ['0'-'9'] -> 6
 */
state0_1:
if(pNext >= pLimit) goto nonaccept0;
current = *pNext++;
if(current < 0x2F) /* ('.') '/' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto nonaccept0;
    goto state0_2;
}
if(current < 0x30) /* ('/') '0' */ 
    goto nonaccept0;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto nonaccept0;
/*
 * DFA STATE 2
 * ['0'-'9'] -> 9
 */
state0_2:
if(pNext >= pLimit) goto nonaccept0;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */ 
    goto nonaccept0;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_9;
goto nonaccept0;
/*
 * DFA STATE 3 (accepts to 0)
 */
state0_3:
pEnd = pNext;
goto accept0_0;
/*
 * DFA STATE 4 (accepts to 12)
 * '.' -> 10
 * '0' -> 11
 * '1' -> 6
 * '2' -> 12
 * ['3'-'4'] -> 6
 * '5' -> 13
 * '6' -> 6
 * '7' -> 14
 * ['8'-'9'] -> 6
 */
state0_4:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x33) /* ('2') '3' */  {
    if(current < 0x30) /* ('/') '0' */  {
        if(current < 0x2E) /* ('-') '.' */ 
            goto accept0_12;
        if(current < 0x2F) /* ('.') '/' */ 
            goto state0_10;
        goto accept0_12;
    }
    if(current < 0x31) /* ('0') '1' */ 
        goto state0_11;
    if(current < 0x32) /* ('1') '2' */ 
        goto state0_6;
    goto state0_12;
}
if(current < 0x37) /* ('6') '7' */  {
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    if(current < 0x36) /* ('5') '6' */ 
        goto state0_13;
    goto state0_6;
}
if(current < 0x38) /* ('7') '8' */ 
    goto state0_14;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 5 (accepts to 12)
 * '.' -> 10
 * '0' -> 15
 * '1' -> 6
 * '2' -> 16
 * ['3'-'4'] -> 6
 * '5' -> 17
 * ['6'-'9'] -> 6
 */
state0_5:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x32) /* ('1') '2' */  {
    if(current < 0x2F) /* ('.') '/' */  {
        if(current < 0x2E) /* ('-') '.' */ 
            goto accept0_12;
        goto state0_10;
    }
    if(current < 0x30) /* ('/') '0' */ 
        goto accept0_12;
    if(current < 0x31) /* ('0') '1' */ 
        goto state0_15;
    goto state0_6;
}
if(current < 0x35) /* ('4') '5' */  {
    if(current < 0x33) /* ('2') '3' */ 
        goto state0_16;
    goto state0_6;
}
if(current < 0x36) /* ('5') '6' */ 
    goto state0_17;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 6 (accepts to 12)
 * '.' -> 10
 * ['0'-'9'] -> 6
 */
state0_6:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x2F) /* ('.') '/' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    goto state0_10;
}
if(current < 0x30) /* ('/') '0' */ 
    goto accept0_12;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 7 (accepts to 12)
 * '.' -> 10
 * '0' -> 18
 * ['1'-'9'] -> 6
 */
state0_7:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x31) /* ('0') '1' */ 
    goto state0_18;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 8 (accepts to 12)
 * '.' -> 10
 * ['0'-'4'] -> 6
 * '5' -> 19
 * ['6'-'9'] -> 6
 */
state0_8:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x36) /* ('5') '6' */  {
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    goto state0_19;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 9 (accepts to 11)
 * ['0'-'9'] -> 9
 * 'E' -> 20
 */
state0_9:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_11;
current = *pNext++;
if(current < 0x3A) /* ('9') ':' */  {
    if(current < 0x30) /* ('/') '0' */ 
        goto accept0_11;
    goto state0_9;
}
if(current < 0x45) /* ('D') 'E' */ 
    goto accept0_11;
if(current < 0x46) /* ('E') 'F' */ 
    goto state0_20;
goto accept0_11;
/*
 * DFA STATE 10
 * ['0'-'9'] -> 9
 */
state0_10:
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */ 
    goto accept0_12;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_9;
goto accept0_12;
/*
 * DFA STATE 11 (accepts to 12)
 * '.' -> 10
 * '0' -> 21
 * ['1'-'9'] -> 6
 */
state0_11:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x31) /* ('0') '1' */ 
    goto state0_21;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 12 (accepts to 12)
 * '.' -> 10
 * ['0'-'4'] -> 6
 * '5' -> 22
 * ['6'-'9'] -> 6
 */
state0_12:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x36) /* ('5') '6' */  {
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    goto state0_22;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 13 (accepts to 12)
 * '.' -> 10
 * '0' -> 23
 * ['1'-'9'] -> 6
 */
state0_13:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x31) /* ('0') '1' */ 
    goto state0_23;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 14 (accepts to 12)
 * '.' -> 10
 * ['0'-'4'] -> 6
 * '5' -> 24
 * ['6'-'9'] -> 6
 */
state0_14:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x36) /* ('5') '6' */  {
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    goto state0_24;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 15 (accepts to 12)
 * '.' -> 10
 * '0' -> 25
 * ['1'-'9'] -> 6
 */
state0_15:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x31) /* ('0') '1' */ 
    goto state0_25;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 16 (accepts to 12)
 * '.' -> 10
 * ['0'-'4'] -> 6
 * '5' -> 26
 * ['6'-'9'] -> 6
 */
state0_16:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_12;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto accept0_12;
    if(current < 0x2F) /* ('.') '/' */ 
        goto state0_10;
    goto accept0_12;
}
if(current < 0x36) /* ('5') '6' */  {
    if(current < 0x35) /* ('4') '5' */ 
        goto state0_6;
    goto state0_26;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_6;
goto accept0_12;
/*
 * DFA STATE 17 (accepts to 1)
 */
state0_17:
pEnd = pNext;
goto accept0_1;
/*
 * DFA STATE 18 (accepts to 2)
 */
state0_18:
pEnd = pNext;
goto accept0_2;
/*
 * DFA STATE 19 (accepts to 3)
 */
state0_19:
pEnd = pNext;
goto accept0_3;
/*
 * DFA STATE 20
 * '+' -> 27
 * '-' -> 27
 * ['0'-'9'] -> 28
 */
state0_20:
if(pNext >= pLimit) goto accept0_11;
current = *pNext++;
if(current < 0x2D) /* (',') '-' */  {
    if(current < 0x2B) /* ('*') '+' */ 
        goto accept0_11;
    if(current < 0x2C) /* ('+') ',' */ 
        goto state0_27;
    goto accept0_11;
}
if(current < 0x30) /* ('/') '0' */  {
    if(current < 0x2E) /* ('-') '.' */ 
        goto state0_27;
    goto accept0_11;
}
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_28;
goto accept0_11;
/*
 * DFA STATE 21 (accepts to 4)
 */
state0_21:
pEnd = pNext;
goto accept0_4;
/*
 * DFA STATE 22 (accepts to 5)
 */
state0_22:
pEnd = pNext;
goto accept0_5;
/*
 * DFA STATE 23 (accepts to 6)
 */
state0_23:
pEnd = pNext;
goto accept0_6;
/*
 * DFA STATE 24 (accepts to 7)
 */
state0_24:
pEnd = pNext;
goto accept0_7;
/*
 * DFA STATE 25 (accepts to 8)
 */
state0_25:
pEnd = pNext;
goto accept0_8;
/*
 * DFA STATE 26 (accepts to 9)
 */
state0_26:
pEnd = pNext;
goto accept0_9;
/*
 * DFA STATE 27
 * ['0'-'9'] -> 28
 */
state0_27:
if(pNext >= pLimit) goto accept0_11;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */ 
    goto accept0_11;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_28;
goto accept0_11;
/*
 * DFA STATE 28 (accepts to 10)
 * ['0'-'9'] -> 28
 */
state0_28:
pEnd = pNext;
if(pNext >= pLimit) goto accept0_10;
current = *pNext++;
if(current < 0x30) /* ('/') '0' */ 
    goto accept0_10;
if(current < 0x3A) /* ('9') ':' */ 
    goto state0_28;
goto accept0_10;


accept0_0:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(0, (int)(pEnd - start)); 
accept0_1:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(1, (int)(pEnd - start)); 
accept0_2:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(2, (int)(pEnd - start)); 
accept0_3:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(3, (int)(pEnd - start)); 
accept0_4:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(4, (int)(pEnd - start)); 
accept0_5:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(5, (int)(pEnd - start)); 
accept0_6:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(6, (int)(pEnd - start)); 
accept0_7:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(7, (int)(pEnd - start)); 
accept0_8:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(8, (int)(pEnd - start)); 
accept0_9:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(9, (int)(pEnd - start)); 
accept0_10:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(10, (int)(pEnd - start)); 
accept0_11:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(11, (int)(pEnd - start)); 
accept0_12:
 pNext = pEnd;
 return new KeyValuePair<ushort,int>(12, (int)(pEnd - start)); 
nonaccept0:
 return null; }
        }
    }
}

The Parser Generator

As a free benefit, the library includes a LR(1) parser generator as well.

We can consider the source code used in ReCode for parsing regular expression syntax:

<#@ template debug="false" hostspecific="false" language="C#" #>
<#@ assembly name="$(SolutionDir)packages\\ReCode.1.0.3\\lib\\452\\ReCode.dll" #>
<#@ import namespace="ReCode" #>
<#@ output extension=".cs" #>
using System;
using System.Collections.Generic;
using ReCode.RegularExpressions.Parsing.Nodes;

namespace ReCode.RegularExpressions.Parsing {
    public partial class RegExParser {
        <#
    foreach (var language in ReCode.ParserTokens(WriteLine, "RegExNode"))
    {
        var g = language.GrammarFromTokens("Expr", "Phrase", "Range", "Star", "Plus", "Question", "ParBegin", "ParEnd", "Bar", "Accept", "Name", "Except");
        var g1 = g.WithPrecedenceGroup();
        if(g1.Matches("Expr", "ParBegin", "Expr", "ParEnd")) {#> res = arg1; <# }
        if(g1.Matches("Expr", "Phrase"))                     {#> res = arg0; <# }
        if(g1.Matches("Expr", "Range"))                      {#> res = arg0; <# }
        if(g1.Matches("Expr", "Name"))                       {#> res = _namedExpressions[(arg0 as RegExNodeName).Name]; <# }
        if(g1.MatchesLeft("Expr", "Expr", "Expr"))           {#> res = new RegExNodeConcat(arg0,arg1); <# }
        if(g1.MatchesLeft("Expr", "Expr", "Bar", "Expr"))    {#> res = RegExNodeUnion.Of(arg0,arg2); <# }
        var g2 = g.WithPrecedenceGroup();
        if(g2.Matches("Expr", "Expr", "Accept"))             {#> res = new RegExNodeAccept(arg0, (arg1 as RegExNodeAccept).AcceptState); <# }
        if(g2.Matches("Expr", "Expr", "Plus"))               {#> res = new RegExNodeRepeat(arg0, RegExRepeatType.OneOrMore); <# }
        if(g2.Matches("Expr", "Expr", "Star"))               {#> res = new RegExNodeRepeat(arg0, RegExRepeatType.ZeroOrMore);<# }
        if(g2.Matches("Expr", "Expr", "Question"))           {#> res = new RegExNodeRepeat(arg0, RegExRepeatType.ZeroOrOne); <# }
        var g3 = g.WithPrecedenceGroup();
        if(g3.MatchesRight("Expr", "Expr", "Except", "Expr")) {#> res = RegExNodeRanges.Except(arg0, arg2); <# }
    }
        #>
    }
}

While this code does not look like much, it translates into the following:

using System;
using System.Collections.Generic;
using ReCode.RegularExpressions.Parsing.Nodes;

namespace ReCode.RegularExpressions.Parsing {
    public partial class RegExParser {
        
        private class ArrayStack<TElm>
        {
          public readonly TElm[] Elements;
          public int Top;
          [System.Runtime.CompilerServices.MethodImplAttribute(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
          public void Reset() { Top = -1; }
          public ArrayStack(int capacity) { Elements = new TElm[capacity]; Top=-1; }
          [System.Runtime.CompilerServices.MethodImplAttribute(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
          public void Push(TElm elm) { Elements[++Top] = elm; }
          [System.Runtime.CompilerServices.MethodImplAttribute(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]
          public void Pop(int count = 1) { Top -= count; }
        }
        const int DefaultStackSize = 50;
        private readonly ArrayStack<int> _stateStack = new ArrayStack<int>(2 * DefaultStackSize);
        private readonly ArrayStack<RegExNode> _valueStack = new ArrayStack<RegExNode>(DefaultStackSize);

        
public enum Token {
  END = 1,
  Phrase = 3,
  Range = 4,
  Star = 5,
  Plus = 6,
  Question = 7,
  ParBegin = 8,
  ParEnd = 9,
  Bar = 10,
  Accept = 11,
  Name = 12,
  Except = 13,
}
public RegExNode Parse() {
  RegExNode res = default(RegExNode);
  var targetTokenType = 0;
  _stateStack.Reset();
  _valueStack.Reset();
  KeyValuePair<Token,RegExNode> currentToken = NextToken();
  _stateStack.Push(0); goto __state_0;

__postReduce:
  /* find on the stack the state where we need to handle post-reduce goto. */
  var gotoState = _stateStack.Elements[_stateStack.Top];
  /* put information on the stack regarding the reduced type. */
  _stateStack.Push(targetTokenType);
  /* jump to the resulting state. */
  switch(gotoState){
  case 0:
    switch(targetTokenType){
    case 2: _stateStack.Push(1); goto __state_1;
    default: goto __syntaxError;
  }
  case 1:
    switch(targetTokenType){
    case 2: _stateStack.Push(6); goto __state_6;
    default: goto __syntaxError;
  }
  case 4:
    switch(targetTokenType){
    case 2: _stateStack.Push(13); goto __state_13;
    default: goto __syntaxError;
  }
  case 6:
    switch(targetTokenType){
    case 2: _stateStack.Push(6); goto __state_6;
    default: goto __syntaxError;
  }
  case 10:
    switch(targetTokenType){
    case 2: _stateStack.Push(18); goto __state_18;
    default: goto __syntaxError;
  }
  case 12:
    switch(targetTokenType){
    case 2: _stateStack.Push(19); goto __state_19;
    default: goto __syntaxError;
  }
  case 13:
    switch(targetTokenType){
    case 2: _stateStack.Push(20); goto __state_20;
    default: goto __syntaxError;
  }
  case 16:
    switch(targetTokenType){
    case 2: _stateStack.Push(28); goto __state_28;
    default: goto __syntaxError;
  }
  case 18:
    switch(targetTokenType){
    case 2: _stateStack.Push(6); goto __state_6;
    default: goto __syntaxError;
  }
  case 19:
    switch(targetTokenType){
    case 2: _stateStack.Push(6); goto __state_6;
    default: goto __syntaxError;
  }
  case 20:
    switch(targetTokenType){
    case 2: _stateStack.Push(20); goto __state_20;
    default: goto __syntaxError;
  }
  case 25:
    switch(targetTokenType){
    case 2: _stateStack.Push(29); goto __state_29;
    default: goto __syntaxError;
  }
  case 27:
    switch(targetTokenType){
    case 2: _stateStack.Push(30); goto __state_30;
    default: goto __syntaxError;
  }
  case 28:
    switch(targetTokenType){
    case 2: _stateStack.Push(20); goto __state_20;
    default: goto __syntaxError;
  }
  case 29:
    switch(targetTokenType){
    case 2: _stateStack.Push(20); goto __state_20;
    default: goto __syntaxError;
  }
  case 30:
    switch(targetTokenType){
    case 2: _stateStack.Push(20); goto __state_20;
    default: goto __syntaxError;
  }
  default:
    goto __syntaxError;
  }

__state_0:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  default:
    goto __syntaxError;
  }

__state_1:
  switch((int)currentToken.Key){
  case 1:
  /* accept value from stack */
  return _valueStack.Elements[_valueStack.Top];
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(7); goto __state_7;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(8); goto __state_8;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(9); goto __state_9;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 10:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(10); goto __state_10;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(11); goto __state_11;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  case 13:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(12); goto __state_12;
  default:
    goto __syntaxError;
  }

__state_2:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 2 */
  goto __action_2;
  default:
    goto __syntaxError;
  }

__state_3:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 3 */
  goto __action_3;
  default:
    goto __syntaxError;
  }

__state_4:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_5:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 4 */
  goto __action_4;
  default:
    goto __syntaxError;
  }

__state_6:
  switch((int)currentToken.Key){
  case 1: case 10: case 13:
  /* do reduce using production 5 */
  goto __action_5;
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(7); goto __state_7;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(8); goto __state_8;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(9); goto __state_9;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(11); goto __state_11;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  default:
    goto __syntaxError;
  }

__state_7:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 9 */
  goto __action_9;
  default:
    goto __syntaxError;
  }

__state_8:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 8 */
  goto __action_8;
  default:
    goto __syntaxError;
  }

__state_9:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 10 */
  goto __action_10;
  default:
    goto __syntaxError;
  }

__state_10:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  default:
    goto __syntaxError;
  }

__state_11:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 7 */
  goto __action_7;
  default:
    goto __syntaxError;
  }

__state_12:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  default:
    goto __syntaxError;
  }

__state_13:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(21); goto __state_21;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(22); goto __state_22;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(23); goto __state_23;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 9:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(24); goto __state_24;
  case 10:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(25); goto __state_25;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(26); goto __state_26;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  case 13:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(27); goto __state_27;
  default:
    goto __syntaxError;
  }

__state_14:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 2 */
  goto __action_2;
  default:
    goto __syntaxError;
  }

__state_15:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 3 */
  goto __action_3;
  default:
    goto __syntaxError;
  }

__state_16:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_17:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 4 */
  goto __action_4;
  default:
    goto __syntaxError;
  }

__state_18:
  switch((int)currentToken.Key){
  case 1: case 10: case 13:
  /* do reduce using production 6 */
  goto __action_6;
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(7); goto __state_7;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(8); goto __state_8;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(9); goto __state_9;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(11); goto __state_11;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  default:
    goto __syntaxError;
  }

__state_19:
  switch((int)currentToken.Key){
  case 1:
  /* do reduce using production 11 */
  goto __action_11;
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(2); goto __state_2;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(3); goto __state_3;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(7); goto __state_7;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(8); goto __state_8;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(9); goto __state_9;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(4); goto __state_4;
  case 10:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(10); goto __state_10;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(11); goto __state_11;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(5); goto __state_5;
  case 13:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(12); goto __state_12;
  default:
    goto __syntaxError;
  }

__state_20:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(21); goto __state_21;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(22); goto __state_22;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(23); goto __state_23;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 9: case 10: case 13:
  /* do reduce using production 5 */
  goto __action_5;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(26); goto __state_26;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_21:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 9 */
  goto __action_9;
  default:
    goto __syntaxError;
  }

__state_22:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 8 */
  goto __action_8;
  default:
    goto __syntaxError;
  }

__state_23:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 10 */
  goto __action_10;
  default:
    goto __syntaxError;
  }

__state_24:
  switch((int)currentToken.Key){
  case 1: case 3: case 4: case 5: case 6: case 7: case 8: case 10: case 11: case 12: case 13:
  /* do reduce using production 1 */
  goto __action_1;
  default:
    goto __syntaxError;
  }

__state_25:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_26:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 7 */
  goto __action_7;
  default:
    goto __syntaxError;
  }

__state_27:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_28:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(21); goto __state_21;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(22); goto __state_22;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(23); goto __state_23;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 9:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(31); goto __state_31;
  case 10:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(25); goto __state_25;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(26); goto __state_26;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  case 13:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(27); goto __state_27;
  default:
    goto __syntaxError;
  }

__state_29:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(21); goto __state_21;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(22); goto __state_22;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(23); goto __state_23;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 9: case 10: case 13:
  /* do reduce using production 6 */
  goto __action_6;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(26); goto __state_26;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  default:
    goto __syntaxError;
  }

__state_30:
  switch((int)currentToken.Key){
  case 3:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(14); goto __state_14;
  case 4:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(15); goto __state_15;
  case 5:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(21); goto __state_21;
  case 6:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(22); goto __state_22;
  case 7:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(23); goto __state_23;
  case 8:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(16); goto __state_16;
  case 9:
  /* do reduce using production 11 */
  goto __action_11;
  case 10:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(25); goto __state_25;
  case 11:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(26); goto __state_26;
  case 12:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(17); goto __state_17;
  case 13:
  /* perform shift to state {action.Target} */
  _valueStack.Push(currentToken.Value);
  _stateStack.Push((int)currentToken.Key);
  currentToken = NextToken();
  _stateStack.Push(27); goto __state_27;
  default:
    goto __syntaxError;
  }

__state_31:
  switch((int)currentToken.Key){
  case 3: case 4: case 5: case 6: case 7: case 8: case 9: case 10: case 11: case 12: case 13:
  /* do reduce using production 1 */
  goto __action_1;
  default:
    goto __syntaxError;
  }


__action_1:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-2];
    var arg1 = _valueStack.Elements[_valueStack.Top-1];
    var arg2 = _valueStack.Elements[_valueStack.Top-0];
 res = arg1;   }
  _valueStack.Pop(3);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(6);
  targetTokenType = 2;
goto __postReduce;

__action_2:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-0];
 res = arg0;   }
  _valueStack.Pop(1);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(2);
  targetTokenType = 2;
goto __postReduce;

__action_3:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-0];
 res = arg0;   }
  _valueStack.Pop(1);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(2);
  targetTokenType = 2;
goto __postReduce;

__action_4:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-0];
 res = _namedExpressions[(arg0 as RegExNodeName).Name];   }
  _valueStack.Pop(1);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(2);
  targetTokenType = 2;
goto __postReduce;

__action_5:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-1];
    var arg1 = _valueStack.Elements[_valueStack.Top-0];
 res = new RegExNodeConcat(arg0,arg1);   }
  _valueStack.Pop(2);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(4);
  targetTokenType = 2;
goto __postReduce;

__action_6:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-2];
    var arg1 = _valueStack.Elements[_valueStack.Top-1];
    var arg2 = _valueStack.Elements[_valueStack.Top-0];
 res = RegExNodeUnion.Of(arg0,arg2);   }
  _valueStack.Pop(3);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(6);
  targetTokenType = 2;
goto __postReduce;

__action_7:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-1];
    var arg1 = _valueStack.Elements[_valueStack.Top-0];
 res = new RegExNodeAccept(arg0, (arg1 as RegExNodeAccept).AcceptState);   }
  _valueStack.Pop(2);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(4);
  targetTokenType = 2;
goto __postReduce;

__action_8:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-1];
    var arg1 = _valueStack.Elements[_valueStack.Top-0];
 res = new RegExNodeRepeat(arg0, RegExRepeatType.OneOrMore);   }
  _valueStack.Pop(2);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(4);
  targetTokenType = 2;
goto __postReduce;

__action_9:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-1];
    var arg1 = _valueStack.Elements[_valueStack.Top-0];
 res = new RegExNodeRepeat(arg0, RegExRepeatType.ZeroOrMore);  }
  _valueStack.Pop(2);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(4);
  targetTokenType = 2;
goto __postReduce;

__action_10:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-1];
    var arg1 = _valueStack.Elements[_valueStack.Top-0];
 res = new RegExNodeRepeat(arg0, RegExRepeatType.ZeroOrOne);   }
  _valueStack.Pop(2);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(4);
  targetTokenType = 2;
goto __postReduce;

__action_11:
  {
    res = default(RegExNode);
    var arg0 = _valueStack.Elements[_valueStack.Top-2];
    var arg1 = _valueStack.Elements[_valueStack.Top-1];
    var arg2 = _valueStack.Elements[_valueStack.Top-0];
 res = RegExNodeRanges.Except(arg0, arg2);   }
  _valueStack.Pop(3);
  _valueStack.Push(res);
  // find goto state and adjust state stack
  _stateStack.Pop(6);
  targetTokenType = 2;
goto __postReduce;
  __syntaxError:
  throw new Exception("Syntax error");
}
    }
}