perf: HtmlCharRefs entity lookup uses Dictionary for O(1) instead of Map O(log n)

github-actions[bot] · Copilot · web-flow · commit 59ea7c447a8e · 2026-04-20T05:01:03.000Z
Replace the F# Map&lt;string, string&gt; (O(log n) per lookup) with a
Dictionary&lt;string, string&gt; (O(1) per lookup) for the ~2230 HTML
named-entity table. Also introduce a static semiColonChars array to
avoid allocating a new char[] on every call to TrimEnd inside the
(|Number|Lookup|) active pattern.

Bump version to 8.1.10.

Co-authored-by: Copilot &lt;223556219+Copilot@users.noreply.github.com&gt;
diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
@@ -1,5 +1,9 @@
 # Release Notes
 
+## 8.1.10 - Apr 20 2026
+
+- Performance: `HtmlCharRefs` entity lookup now uses a `Dictionary<string, string>` instead of an F# `Map`, giving O(1) lookups instead of O(log n) for ~2230 HTML named-entity entries. Also avoids a repeated `char[]` allocation in the `TrimEnd` call inside the active pattern.
+
 ## 8.1.9 - Apr 18 2026
 
 - Fix: `Caching.hashString` now disposes the `SHA1` instance after use; on .NET 5+ uses `SHA1.HashData` (static, pool-backed) to avoid allocation entirely (PR #1745)
diff --git a/src/AssemblyInfo.Csv.Core.fs b/src/AssemblyInfo.Csv.Core.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Csv.Core")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Csv.Core"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.DesignTime.fs b/src/AssemblyInfo.DesignTime.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.DesignTime")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.DesignTime"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.Html.Core.fs b/src/AssemblyInfo.Html.Core.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Html.Core")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Html.Core"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.Http.fs b/src/AssemblyInfo.Http.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Http")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Http"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.Json.Core.fs b/src/AssemblyInfo.Json.Core.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Json.Core")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Json.Core"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.Runtime.Utilities.fs b/src/AssemblyInfo.Runtime.Utilities.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Runtime.Utilities")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Runtime.Utilities"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.WorldBank.Core.fs b/src/AssemblyInfo.WorldBank.Core.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.WorldBank.Core")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.WorldBank.Core"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.Xml.Core.fs b/src/AssemblyInfo.Xml.Core.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data.Xml.Core")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data.Xml.Core"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/AssemblyInfo.fs b/src/AssemblyInfo.fs
@@ -5,13 +5,13 @@ open System.Reflection
 [<assembly: AssemblyTitleAttribute("FSharp.Data")>]
 [<assembly: AssemblyProductAttribute("FSharp.Data")>]
 [<assembly: AssemblyDescriptionAttribute("Library of F# type providers and data access tools")>]
-[<assembly: AssemblyVersionAttribute("8.1.9.0")>]
-[<assembly: AssemblyFileVersionAttribute("8.1.9.0")>]
+[<assembly: AssemblyVersionAttribute("8.1.10.0")>]
+[<assembly: AssemblyFileVersionAttribute("8.1.10.0")>]
 do ()
 
 module internal AssemblyVersionInformation =
     let [<Literal>] AssemblyTitle = "FSharp.Data"
     let [<Literal>] AssemblyProduct = "FSharp.Data"
     let [<Literal>] AssemblyDescription = "Library of F# type providers and data access tools"
-    let [<Literal>] AssemblyVersion = "8.1.9.0"
-    let [<Literal>] AssemblyFileVersion = "8.1.9.0"
+    let [<Literal>] AssemblyVersion = "8.1.10.0"
+    let [<Literal>] AssemblyFileVersion = "8.1.10.0"
diff --git a/src/FSharp.Data.Html.Core/HtmlCharRefs.fs b/src/FSharp.Data.Html.Core/HtmlCharRefs.fs
@@ -1,11 +1,16 @@
 ﻿namespace FSharp.Data
 
 open System
+open System.Collections.Generic
 open System.Globalization
 
 module internal HtmlCharRefs =
 
-    let private refs =
+    // Avoid a new char[] allocation on every TrimEnd call
+    let private semiColonChars = [| ';' |]
+
+    // ~2230 HTML named-entity entries; stored as a Dictionary for O(1) lookup
+    let private refsEntries =
         [| "&Aacute;", "\u00C1"
            "&Aacute", "\u00C1"
            "&aacute;", "\u00E1"
@@ -2237,10 +2242,17 @@ module internal HtmlCharRefs =
            "&zscr;", "\uD835\uDCCF"
            "&zwj;", "\u200D"
            "&zwnj;", "\u200C" |]
-        |> Map.ofArray
+
+    let private refs =
+        let d = Dictionary<string, string>(refsEntries.Length, StringComparer.Ordinal)
+
+        for k, v in refsEntries do
+            d.[k] <- v
+
+        d
 
     let (|Number|Lookup|) (orig: string) =
-        let s = orig.TrimEnd([| ';' |])
+        let s = orig.TrimEnd(semiColonChars)
 
         if s.Length > 2 then
             let (delimeters, discriminator) =
@@ -2275,4 +2287,7 @@ module internal HtmlCharRefs =
                 string lead + string tail
             else
                 string (char num)
-        | Lookup(ref) -> defaultArg (refs.TryFind ref) ref
+        | Lookup(ref) ->
+            match refs.TryGetValue(ref) with
+            | true, v -> v
+            | false, _ -> ref
