File: RegexGenerator.g.cs
Project: src\src\libraries\System.Private.Xml\src\System.Private.Xml.csproj (System.Private.Xml)
// <auto-generated/>
#nullable enable
#pragma warning disable CS0162 // Unreachable code
#pragma warning disable CS0164 // Unreferenced label
#pragma warning disable CS0219 // Variable assigned but never used
 
namespace System.Text.Json
{
    partial class JsonHelpers
    {
        /// <remarks>
        /// Pattern:<br/>
        /// <code>^\s*(?:\+|\-)?[0-9]+\s*$</code><br/>
        /// Explanation:<br/>
        /// <code>
        /// ○ Match if at the beginning of the string.<br/>
        /// ○ Match a whitespace character atomically any number of times.<br/>
        /// ○ Match a character in the set [+\-] atomically, optionally.<br/>
        /// ○ Match a character in the set [0-9] atomically at least once.<br/>
        /// ○ Match a whitespace character greedily any number of times.<br/>
        /// ○ Match if at the end of the string or if before an ending newline.<br/>
        /// </code>
        /// </remarks>
        [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Text.RegularExpressions.Generator", "42.42.42.42")]
        public static partial global::System.Text.RegularExpressions.Regex IntegerRegex => global::System.Text.RegularExpressions.Generated.IntegerRegex_0.Instance;
    }
}
 
namespace System.Text.RegularExpressions.Generated
{
    using System;
    using System.Buffers;
    using System.CodeDom.Compiler;
    using System.Collections;
    using System.ComponentModel;
    using System.Globalization;
    using System.Runtime.CompilerServices;
    using System.Text.RegularExpressions;
    using System.Threading;
 
    /// <summary>Custom <see cref="Regex"/>-derived type for the IntegerRegex method.</summary>
    [GeneratedCodeAttribute("System.Text.RegularExpressions.Generator", "42.42.42.42")]
    [SkipLocalsInit]
    file sealed class IntegerRegex_0 : Regex
    {
        /// <summary>Cached, thread-safe singleton instance.</summary>
        internal static readonly IntegerRegex_0 Instance = new();
    
        /// <summary>Initializes the instance.</summary>
        private IntegerRegex_0()
        {
            base.pattern = "^\\s*(?:\\+|\\-)?[0-9]+\\s*$";
            base.roptions = RegexOptions.None;
            base.internalMatchTimeout = TimeSpan.FromMilliseconds(200);
            base.factory = new RunnerFactory();
            base.capsize = 1;
        }
            
        /// <summary>Provides a factory for creating <see cref="RegexRunner"/> instances to be used by methods on <see cref="Regex"/>.</summary>
        private sealed class RunnerFactory : RegexRunnerFactory
        {
            /// <summary>Creates an instance of a <see cref="RegexRunner"/> used by methods on <see cref="Regex"/>.</summary>
            protected override RegexRunner CreateInstance() => new Runner();
        
            /// <summary>Provides the runner that contains the custom logic implementing the specified regular expression.</summary>
            private sealed class Runner : RegexRunner
            {
                /// <summary>Scan the <paramref name="inputSpan"/> starting from base.runtextstart for the next match.</summary>
                /// <param name="inputSpan">The text being scanned by the regular expression.</param>
                protected override void Scan(ReadOnlySpan<char> inputSpan)
                {
                    // The pattern is anchored.  Validate the current position and try to match at it only.
                    if (TryFindNextPossibleStartingPosition(inputSpan) && !TryMatchAtCurrentPosition(inputSpan))
                    {
                        base.runtextpos = inputSpan.Length;
                    }
                }
        
                /// <summary>Search <paramref name="inputSpan"/> starting from base.runtextpos for the next location a match could possibly start.</summary>
                /// <param name="inputSpan">The text being scanned by the regular expression.</param>
                /// <returns>true if a possible match was found; false if no more matches are possible.</returns>
                private bool TryFindNextPossibleStartingPosition(ReadOnlySpan<char> inputSpan)
                {
                    int pos = base.runtextpos;
                    
                    // Empty matches aren't possible.
                    if ((uint)pos < (uint)inputSpan.Length)
                    {
                        // The pattern leads with a beginning (\A) anchor.
                        if (pos == 0)
                        {
                            return true;
                        }
                    }
                    
                    // No match found.
                    base.runtextpos = inputSpan.Length;
                    return false;
                }
        
                /// <summary>Determine whether <paramref name="inputSpan"/> at base.runtextpos is a match for the regular expression.</summary>
                /// <param name="inputSpan">The text being scanned by the regular expression.</param>
                /// <returns>true if the regular expression matches at the current position; otherwise, false.</returns>
                private bool TryMatchAtCurrentPosition(ReadOnlySpan<char> inputSpan)
                {
                    int pos = base.runtextpos;
                    int matchStart = pos;
                    char ch;
                    int charloop_starting_pos = 0, charloop_ending_pos = 0;
                    ReadOnlySpan<char> slice = inputSpan.Slice(pos);
                    
                    // Match if at the beginning of the string.
                    if (pos != 0)
                    {
                        return false; // The input didn't match.
                    }
                    
                    // Match a whitespace character atomically any number of times.
                    {
                        int iteration = 0;
                        while ((uint)iteration < (uint)slice.Length && char.IsWhiteSpace(slice[iteration]))
                        {
                            iteration++;
                        }
                        
                        slice = slice.Slice(iteration);
                        pos += iteration;
                    }
                    
                    // Match a character in the set [+\-] atomically, optionally.
                    {
                        if (!slice.IsEmpty && (((ch = slice[0]) == '+') | (ch == '-')))
                        {
                            slice = slice.Slice(1);
                            pos++;
                        }
                    }
                    
                    // Match a character in the set [0-9] atomically at least once.
                    {
                        int iteration1 = slice.IndexOfAnyExceptInRange('0', '9');
                        if (iteration1 < 0)
                        {
                            iteration1 = slice.Length;
                        }
                        
                        if (iteration1 == 0)
                        {
                            return false; // The input didn't match.
                        }
                        
                        slice = slice.Slice(iteration1);
                        pos += iteration1;
                    }
                    
                    // Match a whitespace character greedily any number of times.
                    //{
                        charloop_starting_pos = pos;
                        
                        int iteration2 = 0;
                        while ((uint)iteration2 < (uint)slice.Length && char.IsWhiteSpace(slice[iteration2]))
                        {
                            iteration2++;
                        }
                        
                        slice = slice.Slice(iteration2);
                        pos += iteration2;
                        
                        charloop_ending_pos = pos;
                        goto CharLoopEnd;
                        
                        CharLoopBacktrack:
                        
                        base.CheckTimeout();
                        
                        if (charloop_starting_pos >= charloop_ending_pos)
                        {
                            return false; // The input didn't match.
                        }
                        pos = --charloop_ending_pos;
                        slice = inputSpan.Slice(pos);
                        
                        CharLoopEnd:
                    //}
                    
                    // Match if at the end of the string or if before an ending newline.
                    if (pos < inputSpan.Length - 1 || ((uint)pos < (uint)inputSpan.Length && inputSpan[pos] != '\n'))
                    {
                        goto CharLoopBacktrack;
                    }
                    
                    // The input matched.
                    base.runtextpos = pos;
                    base.Capture(0, matchStart, pos);
                    return true;
                }
            }
        }
 
    }
    
}