avoiding Regex

dotnet · Nov 1, 2024 · 0f4a215 · 0f4a215
1 parent 86c372c
commit 0f4a215
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Showing 2 changed files with 22 additions and 19 deletions.
diff --git a/src/Compiler/Driver/CompilerConfig.fs b/src/Compiler/Driver/CompilerConfig.fs
@@ -99,37 +99,42 @@ type WarningNumberSource =
 
 let GetWarningNumber (m, numStr: string, langVersion: LanguageVersion, source: WarningNumberSource) =
     let argFeature = LanguageFeature.ParsedHashDirectiveArgumentNonQuotes
-    let rxOptions = RegexOptions.CultureInvariant
 
     let warnInvalid () =
         warning (Error(FSComp.SR.buildInvalidWarningNumber numStr, m))
 
-    let getNumber regexString failAction =
-        let mtch = Regex(regexString, rxOptions).Match(numStr)
-
-        if mtch.Success then
-            Some(int mtch.Groups[2].Captures[0].Value)
-        else
+    let tryParseIntWithFailAction (s: string) (failAction: unit -> unit) =
+        match Int32.TryParse s with
+        | true, n -> Some n
+        | false, _ ->
             failAction ()
             None
 
-    let matches regexString =
-        Regex(regexString, rxOptions).Match(numStr).Success
-
     if source = WarningNumberSource.CommandLineOption then
-        getNumber """^(FS)?(\d+)$""" (fun () ->
-            if not (matches """^([A-Z]+)(\d+)$""") then
-                warnInvalid ())
+        let s =
+            if numStr.StartsWithOrdinal "FS" then
+                numStr[2..]
+            else
+                numStr
+
+        tryParseIntWithFailAction s id
     elif langVersion.SupportsFeature(argFeature) then
-        getNumber """^("?)(?:(?:FS)?(\d+))\1$""" warnInvalid
-    elif matches """^[^"].+$""" then
+        let s =
+            if numStr[0] = '"' && numStr[numStr.Length - 1] = '"' then
+                numStr[1 .. numStr.Length - 2]
+            else
+                numStr
+
+        let s = if s.StartsWithOrdinal "FS" then s[2..] else s
+        tryParseIntWithFailAction s warnInvalid
+    elif numStr[0] <> '"' || numStr[numStr.Length - 1] <> '"' then
         errorR (languageFeatureError langVersion argFeature m)
         None
-    elif matches """^"FS.*"$""" then
+    elif numStr.StartsWith "\"FS" && numStr[numStr.Length - 1] = '"' then
         warnInvalid ()
         None
     else
-        getNumber """^(")(\d+)"$""" (fun () -> ())
+        tryParseIntWithFailAction numStr id
 
 let ComputeMakePathAbsolute implicitIncludeDir (path: string) =
     try

diff --git a/tests/FSharp.Compiler.ComponentTests/CompilerDirectives/NonStringArgs.fs b/tests/FSharp.Compiler.ComponentTests/CompilerDirectives/NonStringArgs.fs
@@ -167,8 +167,6 @@ match None with None -> ()      // creates FS0025 - ignored due to flag
         |> compile
         |> shouldFail
         |> withDiagnostics [
-                (Warning 203, Line 0, Col 1, Line 0, Col 1, "Invalid warning number 'FS'")
-                (Warning 203, Line 0, Col 1, Line 0, Col 1, "Invalid warning number 'FSBLAH'")
                 (Warning 988, Line 3, Col 3, Line 3, Col 3, "Main module of program is empty: nothing will happen when it is run")
             ]