FPropose 1.2.0

FPropose

Composable predicates for F# that return a boolean and explain why that result holds for a specific value. Explanations can follow normal short-circuiting (Lazy) or evaluate every sub-predicate for auditing (Eager).

Install

dotnet add package FPropose

Quick example

open FPropose
open FPropose.Operators

let canVote =
    Pred.leafMsg "age" (fun p -> p.Age >= 18)
        (fun _ -> "Meets minimum age.")
        (fun p -> $"Age {p.Age} is below 18.")

let registered =
    Pred.leafMsg "registered" (fun p -> p.Registered)
        (fun _ -> "Account is registered.")
        (fun _ -> "Account is not registered.")

let p = canVote .&&. registered
let person = {| Name = "Ada"; Age = 17; Registered = false |}

if Pred.eval p person then
    printfn "OK"
else
    printfn "%s" (Pred.explainText ExplainMode.Lazy p person)

ExplainTree captures structure; call .Format() or ExplainTree.format for plain text.

API overview

Developing locally

Prerequisites: .NET 8 SDK.

git clone https://github.com/icalvo/FPropose.git
cd FPropose
dotnet restore
dotnet build
dotnet test

Open as a workspace

In Cursor or VS Code, use File → Open Folder and select the FPropose directory (the folder that contains FPropose.sln).

Repository

Source lives at github.com/icalvo/FPropose. If you cloned without a remote:

git remote add origin https://github.com/icalvo/FPropose.git
git push -u origin master

Project layout

• CHANGELOG.md — release history (Keep a Changelog)
• src/FPropose — library (Explain.fs, Pred.fs)
• tests/FPropose.Tests — xUnit tests

Agent releases: load the deploy-release skill (.cursor/skills/deploy-release/SKILL.md) for changelog → tag → GitHub Release → NuGet publish.

Packaging locally

dotnet pack src/FPropose/FPropose.fsproj -c Release -o ./artifacts -p:PackageVersion=0.1.0-local

Outputs .nupkg (and symbols) under ./artifacts.

Publishing to NuGet.org (CI)

One-time setup

1. Use this repository (icalvo/FPropose); Directory.Build.props and this README already point at it.
2. Create an API key on NuGet.org with Push scope for package id FPropose.
3. In the GitHub repo, add a secret named NUGET_API_KEY containing that key (Settings → Secrets and variables → Actions).

Publish when you cut a GitHub Release

1. Update Version / release notes as needed.
2. Create a Release in GitHub and publish it. Use a tag like v0.2.0 (the workflow strips a leading v for the package version).
3. The Publish to NuGet workflow packs FPropose and runs dotnet nuget push to https://api.nuget.org/v3/index.json.

Publish manually from Actions

1. Go to Actions → Publish to NuGet → Run workflow.
2. Enter a SemVer version (e.g. 0.2.0).

After the first publish

Confirm the package appears on NuGet Gallery. If the id is taken, change <PackageId> in src/FPropose/FPropose.fsproj and the secret scope to match.

License

MIT — see LICENSE.