Add more char.Is helpers for common ASCII sets

src/coreclr/System.Private.CoreLib/src/System/Reflection/Emit/SymbolType.cs

@@ -87,7 +87,7 @@ public override bool IsAssignableFrom([NotNullWhen(true)] TypeInfo? typeInfo)
                         curIndex++;
                     }
                     // consume, one dimension at a time
-                    if ((format[curIndex] >= '0' && format[curIndex] <= '9') || format[curIndex] == '-')
+                    if (char.IsAsciiDigit(format[curIndex]) || format[curIndex] == '-')
                     {
                         bool isNegative = false;
                         if (format[curIndex] == '-')
@@ -97,7 +97,7 @@ public override bool IsAssignableFrom([NotNullWhen(true)] TypeInfo? typeInfo)
                         }
 
                         // lower bound is specified. Consume the low bound
-                        while (format[curIndex] >= '0' && format[curIndex] <= '9')
+                        while (char.IsAsciiDigit(format[curIndex]))
                         {
                             iLowerBound *= 10;
                             iLowerBound += format[curIndex] - '0';
@@ -126,7 +126,7 @@ public override bool IsAssignableFrom([NotNullWhen(true)] TypeInfo? typeInfo)
 
                         curIndex++;
                         // consume the upper bound
-                        if ((format[curIndex] >= '0' && format[curIndex] <= '9') || format[curIndex] == '-')
+                        if (char.IsAsciiDigit(format[curIndex]) || format[curIndex] == '-')
                         {
                             bool isNegative = false;
                             iUpperBound = 0;
@@ -137,7 +137,7 @@ public override bool IsAssignableFrom([NotNullWhen(true)] TypeInfo? typeInfo)
                             }
 
                             // lower bound is specified. Consume the low bound
-                            while (format[curIndex] >= '0' && format[curIndex] <= '9')
+                            while (char.IsAsciiDigit(format[curIndex]))
                             {
                                 iUpperBound *= 10;
                                 iUpperBound += format[curIndex] - '0';

src/libraries/Common/src/System/Globalization/FormatProvider.Number.cs

@@ -440,7 +440,7 @@ private static unsafe bool ParseNumber(ref char* str, char* strEnd, NumberStyles
                 int digEnd = 0;
                 while (true)
                 {
-                    if ((ch >= '0' && ch <= '9') || (((options & NumberStyles.AllowHexSpecifier) != 0) && ((ch >= 'a' && ch <= 'f') || (ch >= 'A' && ch <= 'F'))))
+                    if (char.IsAsciiDigit(ch) || (((options & NumberStyles.AllowHexSpecifier) != 0) && char.IsBetween((char)(ch | 0x20), 'a', 'f')))
                     {
                         state |= StateDigits;
 
@@ -510,7 +510,7 @@ private static unsafe bool ParseNumber(ref char* str, char* strEnd, NumberStyles
                             ch = (p = next) < strEnd ? *p : '\0';
                             negExp = true;
                         }
-                        if (ch >= '0' && ch <= '9')
+                        if (char.IsAsciiDigit(ch))
                         {
                             int exp = 0;
                             do
@@ -520,12 +520,12 @@ private static unsafe bool ParseNumber(ref char* str, char* strEnd, NumberStyles
                                 if (exp > 1000)
                                 {
                                     exp = 9999;
-                                    while (ch >= '0' && ch <= '9')
+                                    while (char.IsAsciiDigit(ch))
                                     {
                                         ch = ++p < strEnd ? *p : '\0';
                                     }
                                 }
-                            } while (ch >= '0' && ch <= '9');
+                            } while (char.IsAsciiDigit(ch));
                             if (negExp)
                             {
                                 exp = -exp;
@@ -678,8 +678,7 @@ internal static char ParseFormatSpecifier(ReadOnlySpan<char> format, out int dig
                     // If the format begins with a symbol, see if it's a standard format
                     // with or without a specified number of digits.
                     c = format[0];
-                    if ((uint)(c - 'A') <= 'Z' - 'A' ||
-                        (uint)(c - 'a') <= 'z' - 'a')
+                    if (char.IsAsciiLetter(c))
                     {
                         // Fast path for sole symbol, e.g. "D"
                         if (format.Length == 1)
@@ -714,7 +713,7 @@ internal static char ParseFormatSpecifier(ReadOnlySpan<char> format, out int dig
                         // digits.  Further, for compat, we need to stop when we hit a null char.
                         int n = 0;
                         int i = 1;
-                        while (i < format.Length && (((uint)format[i] - '0') < 10))
+                        while ((uint)i < (uint)format.Length && char.IsAsciiDigit(format[i]))
                         {
                             int temp = (n * 10) + format[i++] - '0';
                             if (temp < n)

src/libraries/Common/src/System/IO/PathInternal.Windows.cs

@@ -69,7 +69,7 @@ internal static partial class PathInternal
         /// </summary>
         internal static bool IsValidDriveChar(char value)
         {
-            return (value >= 'A' && value <= 'Z') || (value >= 'a' && value <= 'z');
+            return (uint)((value | 0x20) - 'a') <= (uint)('z' - 'a');
         }
 
         internal static bool EndsWithPeriodOrSpace(string? path)

src/libraries/Common/src/System/Net/IPv4AddressHelper.Common.cs

@@ -126,7 +126,7 @@ internal static unsafe bool IsValidCanonical(char* name, int start, ref int end,
                     break;
                 }
 
-                if (ch <= '9' && ch >= '0')
+                if (char.IsAsciiDigit(ch))
                 {
                     if (!haveNumber && (ch == '0'))
                     {
@@ -217,7 +217,7 @@ internal static unsafe long ParseNonCanonical(char* name, int start, ref int end
                     ch = name[current];
                     int digitValue;
 
-                    if ((numberBase == Decimal || numberBase == Hex) && '0' <= ch && ch <= '9')
+                    if ((numberBase == Decimal || numberBase == Hex) && char.IsAsciiDigit(ch))
                     {
                         digitValue = ch - '0';
                     }

src/libraries/Common/src/System/Net/IPv6AddressHelper.Common.cs

@@ -123,7 +123,7 @@ internal static unsafe bool IsValidStrict(char* name, int start, ref int end)
             int i;
             for (i = start; i < end; ++i)
             {
-                if (Uri.IsHexDigit(name[i]))
+                if (char.IsAsciiHexDigit(name[i]))
                 {
                     ++sequenceLength;
                     expectingNumber = false;
@@ -176,7 +176,7 @@ internal static unsafe bool IsValidStrict(char* name, int start, ref int end)
                                 i += 4;
                                 for (; i < end; i++)
                                 {
-                                    if (!Uri.IsHexDigit(name[i]))
+                                    if (!char.IsAsciiHexDigit(name[i]))
                                     {
                                         return false;
                                     }
@@ -187,7 +187,7 @@ internal static unsafe bool IsValidStrict(char* name, int start, ref int end)
                                 i += 2;
                                 for (; i < end; i++)
                                 {
-                                    if (name[i] < '0' || name[i] > '9')
+                                    if (!char.IsAsciiDigit(name[i]))
                                     {
                                         return false;
                                     }

src/libraries/System.ComponentModel.Annotations/src/System/ComponentModel/DataAnnotations/CreditCardAttribute.cs

@@ -35,8 +35,8 @@ public override bool IsValid(object? value)
             // Note: string.Reverse() does not exist for WinPhone
             for (var i = ccValue.Length - 1; i >= 0; i--)
             {
-                var digit = ccValue[i];
-                if (digit < '0' || digit > '9')
+                char digit = ccValue[i];
+                if (!char.IsAsciiDigit(digit))
                 {
                     return false;
                 }

src/libraries/System.ComponentModel.TypeConverter/src/System/ComponentModel/MaskedTextProvider.cs

@@ -1395,14 +1395,6 @@ private static bool IsAscii(char c)
             return (c >= '!' && c <= '~');
         }
 
-        /// <summary>
-        /// Helper function for alphanumeric char in ascii mode.
-        /// </summary>
-        private static bool IsAciiAlphanumeric(char c)
-        {
-            return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
-        }
-
         /// <summary>
         /// Helper function for testing mask language alphanumeric identifiers.
         /// </summary>
@@ -1411,14 +1403,6 @@ private static bool IsAlphanumeric(char c)
             return char.IsLetter(c) || char.IsDigit(c);
         }
 
-        /// <summary>
-        /// Helper function for testing letter char in ascii mode.
-        /// </summary>
-        private static bool IsAsciiLetter(char c)
-        {
-            return (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z');
-        }
-
         /// <summary>
         /// Checks whether the specified position is available for assignment. Returns false if it is assigned
         /// or it is not editable, true otherwise.
@@ -2302,7 +2286,7 @@ private bool TestChar(char input, int position, out MaskedTextResultHint resultH
                         resultHint = MaskedTextResultHint.LetterExpected;
                         return false;
                     }
-                    if (!IsAsciiLetter(input) && AsciiOnly)
+                    if (!char.IsAsciiLetter(input) && AsciiOnly)
                     {
                         resultHint = MaskedTextResultHint.AsciiCharacterExpected;
                         return false;
@@ -2315,7 +2299,7 @@ private bool TestChar(char input, int position, out MaskedTextResultHint resultH
                         resultHint = MaskedTextResultHint.LetterExpected;
                         return false;
                     }
-                    if (!IsAsciiLetter(input) && AsciiOnly)
+                    if (!char.IsAsciiLetter(input) && AsciiOnly)
                     {
                         resultHint = MaskedTextResultHint.AsciiCharacterExpected;
                         return false;
@@ -2344,7 +2328,7 @@ private bool TestChar(char input, int position, out MaskedTextResultHint resultH
                         resultHint = MaskedTextResultHint.AlphanumericCharacterExpected;
                         return false;
                     }
-                    if (!IsAciiAlphanumeric(input) && AsciiOnly)
+                    if (!char.IsAsciiLetterOrDigit(input) && AsciiOnly)
                     {
                         resultHint = MaskedTextResultHint.AsciiCharacterExpected;
                         return false;
@@ -2357,7 +2341,7 @@ private bool TestChar(char input, int position, out MaskedTextResultHint resultH
                         resultHint = MaskedTextResultHint.AlphanumericCharacterExpected;
                         return false;
                     }
-                    if (!IsAciiAlphanumeric(input) && AsciiOnly)
+                    if (!char.IsAsciiLetterOrDigit(input) && AsciiOnly)
                     {
                         resultHint = MaskedTextResultHint.AsciiCharacterExpected;
                         return false;

src/libraries/System.Console/src/System/ConsolePal.Unix.cs

@@ -629,7 +629,7 @@ static void ReadRowOrCol(int startExclusive, int endExclusive, StdInReader reade
                     for (int i = startExclusive + 1; i < endExclusive; i++)
                     {
                         byte b = source[i];
-                        if (IsDigit(b))
+                        if (char.IsAsciiDigit((char)b))
                         {
                             try
                             {
@@ -675,9 +675,6 @@ public static void MoveBufferArea(int sourceLeft, int sourceTop, int sourceWidth
             throw new PlatformNotSupportedException();
         }
 
-        /// <summary>Gets whether the specified character is a digit 0-9.</summary>
-        private static bool IsDigit(byte c) => c >= '0' && c <= '9';
-
         /// <summary>
         /// Gets whether the specified file descriptor was redirected.
         /// It's considered redirected if it doesn't refer to a terminal.

src/libraries/System.Console/src/System/IO/StdInReader.cs

@@ -344,27 +344,27 @@ internal static ConsoleKey GetKeyFromCharValue(char x, out bool isShift, out boo
 
                 default:
                     // 1. Ctrl A to Ctrl Z.
-                    if (x >= 1 && x <= 26)
+                    if (char.IsBetween(x, (char)1, (char)26))
                     {
                         isCtrl = true;
                         return ConsoleKey.A + x - 1;
                     }
 
                     // 2. Numbers from 0 to 9.
-                    if (x >= '0' && x <= '9')
+                    if (char.IsAsciiDigit(x))
                     {
                         return ConsoleKey.D0 + x - '0';
                     }
 
                     //3. A to Z
-                    if (x >= 'A' && x <= 'Z')
+                    if (char.IsAsciiLetterUpper(x))
                     {
                         isShift = true;
                         return ConsoleKey.A + (x - 'A');
                     }
 
                     // 4. a to z.
-                    if (x >= 'a' && x <= 'z')
+                    if (char.IsAsciiLetterLower(x))
                     {
                         return ConsoleKey.A + (x - 'a');
                     }

src/libraries/System.Console/src/System/TermInfo.cs

@@ -687,7 +687,7 @@ public static string Evaluate(string format, params FormatParam[] args)
                         // Stack pushing operations
                         case 'p': // Push the specified parameter (1-based) onto the stack
                             pos++;
-                            Debug.Assert(format[pos] >= '0' && format[pos] <= '9');
+                            Debug.Assert(char.IsAsciiDigit(format[pos]));
                             stack.Push(args[format[pos] - '1']);
                             break;
                         case 'l': // Pop a string and push its length
@@ -698,7 +698,7 @@ public static string Evaluate(string format, params FormatParam[] args)
                             int intLit = 0;
                             while (format[pos] != '}')
                             {
-                                Debug.Assert(format[pos] >= '0' && format[pos] <= '9');
+                                Debug.Assert(char.IsAsciiDigit(format[pos]));
                                 intLit = (intLit * 10) + (format[pos] - '0');
                                 pos++;
                             }
@@ -900,12 +900,12 @@ private static unsafe string FormatPrintF(string format, object arg)
             private static FormatParam[] GetDynamicOrStaticVariables(
                 char c, ref FormatParam[]? dynamicVars, ref FormatParam[]? staticVars, out int index)
             {
-                if (c >= 'A' && c <= 'Z')
+                if (char.IsAsciiLetterUpper(c))
                 {
                     index = c - 'A';
                     return staticVars ?? (staticVars = new FormatParam[26]); // one slot for each letter of alphabet
                 }
-                else if (c >= 'a' && c <= 'z')
+                else if (char.IsAsciiLetterLower(c))
                 {
                     index = c - 'a';
                     return dynamicVars ?? (dynamicVars = new FormatParam[26]); // one slot for each letter of alphabet

src/libraries/System.Data.Common/src/System/Data/SQLTypes/SQLDecimal.cs

@@ -1073,15 +1073,19 @@ public static SqlDecimal Parse(string s)
                 usChar = rgwchStr[iCurChar];
                 iCurChar++;
 
-                if (usChar >= '0' && usChar <= '9')
+                if (char.IsAsciiDigit(usChar))
+                {
                     usChar -= '0';
+                }
                 else if (usChar == '.' && lDecPnt < 0)
                 {
                     lDecPnt = iData;
                     continue;
                 }
                 else
+                {
                     throw new FormatException(SQLResource.FormatMessage);
+                }
 
                 snResult.MultByULong(s_ulBase10);
                 snResult.AddULong(usChar);

src/libraries/System.Diagnostics.FileVersionInfo/src/System/Diagnostics/FileVersionInfo.Unix.cs

@@ -234,7 +234,7 @@ private static ushort ParseUInt16UntilNonDigit(string s, out bool endedEarly)
             for (int index = 0; index < s.Length; index++)
             {
                 char c = s[index];
-                if (c < '0' || c > '9')
+                if (!char.IsAsciiDigit(c))
                 {
                     endedEarly = true;
                     break;

src/libraries/System.Net.Http/src/System/Net/Http/Headers/AltSvcHeaderParser.cs

@@ -442,7 +442,7 @@ private static bool TryReadQuotedInt32Value(ReadOnlySpan<char> value, out int re
                 // The port shouldn't ever need a quoted-pair, but they're still valid... skip if found.
                 if (ch == '\\') continue;
 
-                if ((uint)(ch - '0') > '9' - '0') // ch < '0' || ch > '9'
+                if (!char.IsAsciiDigit(ch))
                 {
                     result = 0;
                     return false;

src/libraries/System.Net.Http/src/System/Net/Http/Headers/RetryConditionHeaderValue.cs

@@ -126,7 +126,7 @@ internal static int GetRetryConditionLength(string? input, int startIndex, out o
             // If it is a number, we have a timespan, otherwise we assume we have a date.
             char firstChar = input[current];
 
-            if ((firstChar >= '0') && (firstChar <= '9'))
+            if (char.IsAsciiDigit(firstChar))
             {
                 int deltaStartIndex = current;
                 int deltaLength = HttpRuleParser.GetNumberLength(input, current, false);

src/libraries/System.Net.Http/src/System/Net/Http/HttpRuleParser.cs

@@ -177,7 +177,7 @@ internal static int GetNumberLength(string input, int startIndex, bool allowDeci
             while (current < input.Length)
             {
                 c = input[current];
-                if ((c >= '0') && (c <= '9'))
+                if (char.IsAsciiDigit(c))
                 {
                     current++;
                 }

src/libraries/System.Net.Http/src/System/Net/Http/MultipartContent.cs

@@ -89,14 +89,8 @@ private static void ValidateBoundary(string boundary)
 
             foreach (char ch in boundary)
             {
-                if (('0' <= ch && ch <= '9') || // Digit.
-                    ('a' <= ch && ch <= 'z') || // alpha.
-                    ('A' <= ch && ch <= 'Z') || // ALPHA.
-                    (AllowedMarks.Contains(ch))) // Marks.
-                {
-                    // Valid.
-                }
-                else
+                if (!char.IsAsciiLetterOrDigit(ch) &&
+                    !AllowedMarks.Contains(ch)) // Marks.
                 {
                     throw new ArgumentException(SR.Format(System.Globalization.CultureInfo.InvariantCulture, SR.net_http_headers_invalid_value, boundary), nameof(boundary));
                 }

src/libraries/System.Net.HttpListener/src/System/Net/Managed/HttpListenerRequest.Managed.cs

@@ -87,10 +87,8 @@ internal void SetRequestLine(string req)
             _method = parts[0];
             foreach (char c in _method)
             {
-                int ic = (int)c;
-
-                if ((ic >= 'A' && ic <= 'Z') ||
-                    (ic > 32 && c < 127 && c != '(' && c != ')' && c != '<' &&
+                if (char.IsAsciiLetterUpper(c) ||
+                    (c > 32 && c < 127 && c != '(' && c != ')' && c != '<' &&
                      c != '<' && c != '>' && c != '@' && c != ',' && c != ';' &&
                      c != ':' && c != '\\' && c != '"' && c != '/' && c != '[' &&
                      c != ']' && c != '?' && c != '=' && c != '{' && c != '}'))