update version logic

Author: dsyme

AGENTS.md

@@ -10,7 +10,7 @@ FSharp.Control.TaskSeq is an F# library providing a `taskSeq` computation expres
 - `src/FSharp.Control.TaskSeq.Test/` — xUnit test project (net9.0)
 - `src/FSharp.Control.TaskSeq.SmokeTests/` — Smoke/integration tests
 - `src/FSharp.Control.TaskSeq.sln` — Solution file
-- `Version.props` — Single source of truth for the package version
+- `Version.props` — Package version (derived automatically from `release-notes.txt`)
 - `build.cmd` — Windows build/test script used by CI
 
 ## Build
@@ -102,12 +102,28 @@ All workflows are in `.github/workflows/`:
 
 ## Release Notes
 
-**Required**: Every PR that adds features, fixes bugs, or makes user-visible changes **must** include an update to `release-notes.txt`. Add a bullet under the appropriate version heading (currently `0.5.0`). The format is:
+`release-notes.txt` is the **single source of truth** for the package version. `Version.props` extracts the version automatically by finding the first line that matches a `X.Y.Z` semver pattern. The `Unreleased` section at the top of the file is skipped because it does not match this pattern.
+
+**Format requirements:**
+
+- The file **must** always begin with a heading line `Unreleased` (after the optional `Release notes:` header). This section holds in-progress changes before they are assigned a version number. It must always be present, even if empty.
+- Below `Unreleased`, versioned sections are listed in descending order (`1.0.0`, `0.7.0`, …). The topmost versioned section determines the package version.
+- To bump the version, add a new version heading between `Unreleased` and the previous version.
+
+Example:
 
 ```
-0.5.0
+Release notes:
+
+Unreleased
+    - upcoming change description
+
+1.1.0
     - adds TaskSeq.myFunction and TaskSeq.myFunctionAsync, #<issue>
     - fixes <description>, #<issue>
+
+1.0.0
+    - adds TaskSeq.withCancellation, #167
 ```
 
-If you are bumping to a new version, also update `Version.props`. PRs that touch library source (`src/FSharp.Control.TaskSeq/`) without updating `release-notes.txt` are incomplete.
+**Required**: Every PR that adds features, fixes bugs, or makes user-visible changes **must** add a bullet under the `Unreleased` heading in `release-notes.txt`. PRs that touch library source (`src/FSharp.Control.TaskSeq/`) without updating `release-notes.txt` are incomplete.

Version.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <!-- updating this version will trigger a publish after merge to 'main' -->
-    <Version>1.0.1</Version>
+    <!-- Version is extracted from the first versioned section heading in release-notes.txt -->
+    <Version>$([System.Text.RegularExpressions.Regex]::Match($([System.IO.File]::ReadAllText(`$(MSBuildThisFileDirectory)release-notes.txt`)), `(?m)^(\d+\.\d+\.\d+)`).Groups.get_Item(1).Value)</Version>
   </PropertyGroup>
 </Project>

release-notes.txt

@@ -1,7 +1,7 @@
 
 Release notes:
 
-1.0.1
+Unreleased
     - adds taskSeqDynamic computation expression and TaskSeqDynamic/TaskSeqDynamicInfo types for dynamic (FSI-compatible) resumable code, fixing issue where taskSeq would raise NotImplementedException in F# Interactive, #246
     - perf: simplify iter, fold, reduce, mapFold, tryLast, skipOrTake (Drop/Truncate) to use while! and remove manual go-flag and initial MoveNextAsync pre-advance, matching the pattern already used by sum/sumBy/average
     - perf: toResizeArrayAsync (and therefore toArrayAsync, toListAsync, toResizeArrayAsync, toIListAsync) uses a direct loop instead of going through iter, avoiding a lambda and DU allocation per call