3 files changed, 168 insertions, 0 deletions
diff --git a/users/Profpatsch/arglib/ArglibNetencode.hs b/users/Profpatsch/arglib/ArglibNetencode.hs
new file mode 100644
index 0000000000..4531151ca2
--- /dev/null
+++ b/users/Profpatsch/arglib/ArglibNetencode.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module ArglibNetencode where
+
+import Data.Attoparsec.ByteString qualified as Atto
+import ExecHelpers
+import Label
+import Netencode qualified
+import PossehlAnalyticsPrelude
+import System.Posix.Env.ByteString qualified as ByteEnv
+
+arglibNetencode :: CurrentProgramName -> Maybe (Label "arglibEnvvar" Text) -> IO Netencode.T
+arglibNetencode progName mEnvvar = do
+  let envvar = mEnvvar <&> (.arglibEnvvar) & fromMaybe "ARGLIB_NETENCODE" & textToBytesUtf8
+  ByteEnv.getEnv envvar >>= \case
+    Nothing -> dieUserError progName [fmt|could not read args, envvar {envvar} not set|]
+    Just bytes ->
+      case Atto.parseOnly (Netencode.netencodeParser <* Atto.endOfInput) bytes of
+        Left err -> dieEnvironmentProblem progName [fmt|arglib parsing error: {err}|]
+        Right t -> do
+          ByteEnv.unsetEnv envvar
+          pure t
diff --git a/users/Profpatsch/arglib/arglib-netencode.cabal b/users/Profpatsch/arglib/arglib-netencode.cabal
new file mode 100644
index 0000000000..42b524f405
--- /dev/null
+++ b/users/Profpatsch/arglib/arglib-netencode.cabal
@@ -0,0 +1,65 @@
+cabal-version:      3.0
+name:               arglib-netencode
+version:            0.1.0.0
+author:             Profpatsch
+maintainer:         mail@profpatsch.de
+
+common common-options
+  ghc-options:
+      -Wall
+      -Wno-type-defaults
+      -Wunused-packages
+      -Wredundant-constraints
+      -fwarn-missing-deriving-strategies
+
+  -- See https://downloads.haskell.org/ghc/latest/docs/users_guide/exts.html
+  -- for a description of all these extensions
+  default-extensions:
+      -- Infer Applicative instead of Monad where possible
+    ApplicativeDo
+
+    -- Allow literal strings to be Text
+    OverloadedStrings
+
+    -- Syntactic sugar improvements
+    LambdaCase
+    MultiWayIf
+
+    -- Makes the (deprecated) usage of * instead of Data.Kind.Type an error
+    NoStarIsType
+
+    -- Convenient and crucial to deal with ambiguous field names, commonly
+    -- known as RecordDotSyntax
+    OverloadedRecordDot
+
+    -- does not export record fields as functions, use OverloadedRecordDot to access instead
+    NoFieldSelectors
+
+    -- Record punning
+    RecordWildCards
+
+    -- Improved Deriving
+    DerivingStrategies
+    DerivingVia
+
+    -- Type-level strings
+    DataKinds
+
+    -- to enable the `type` keyword in import lists (ormolu uses this automatically)
+    ExplicitNamespaces
+
+  default-language: GHC2021
+
+
+library
+    import: common-options
+    exposed-modules:          ArglibNetencode
+
+    build-depends:
+        base >=4.15 && <5,
+        pa-prelude,
+        pa-label,
+        netencode,
+        exec-helpers,
+        attoparsec,
+        unix
diff --git a/users/Profpatsch/arglib/netencode.nix b/users/Profpatsch/arglib/netencode.nix
new file mode 100644
index 0000000000..83a94ddd6c
--- /dev/null
+++ b/users/Profpatsch/arglib/netencode.nix
@@ -0,0 +1,81 @@
+{ depot, pkgs, lib, ... }:
+
+let
+
+  # Add the given nix arguments to the program as ARGLIB_NETENCODE envvar
+  #
+  # Calls `netencode.gen.dwim` on the provided nix args value.
+  with-args = name: args: prog: depot.nix.writeExecline "${name}-with-args" { } [
+    "export"
+    "ARGLIB_NETENCODE"
+    (depot.users.Profpatsch.netencode.gen.dwim args)
+    prog
+  ];
+
+  rust = depot.nix.writers.rustSimpleLib
+    {
+      name = "arglib-netencode";
+      dependencies = [
+        depot.users.Profpatsch.execline.exec-helpers
+        depot.users.Profpatsch.netencode.netencode-rs
+      ];
+    } ''
+    extern crate netencode;
+    extern crate exec_helpers;
+
+    use netencode::{T};
+    use std::os::unix::ffi::OsStrExt;
+
+    pub fn arglib_netencode(prog_name: &str, env: Option<&std::ffi::OsStr>) -> T {
+        let env = match env {
+            None => std::ffi::OsStr::from_bytes("ARGLIB_NETENCODE".as_bytes()),
+            Some(a) => a
+        };
+        let t = match std::env::var_os(env) {
+            None => exec_helpers::die_user_error(prog_name, format!("could not read args, envvar {} not set", env.to_string_lossy())),
+            // TODO: good error handling for the different parser errors
+            Some(soup) => match netencode::parse::t_t(soup.as_bytes()) {
+                Ok((remainder, t)) => match remainder.is_empty() {
+                    true => t,
+                    false => exec_helpers::die_environment_problem(prog_name, format!("arglib: there was some unparsed bytes remaining: {:?}", remainder))
+                },
+                Err(err) => exec_helpers::die_environment_problem(prog_name, format!("arglib parsing error: {:?}", err))
+            }
+        };
+        std::env::remove_var(env);
+        t
+    }
+  '';
+
+  haskell = pkgs.haskellPackages.mkDerivation {
+    pname = "arglib-netencode";
+    version = "0.1.0";
+
+    src = depot.users.Profpatsch.exactSource ./. [
+      ./arglib-netencode.cabal
+      ./ArglibNetencode.hs
+    ];
+
+    libraryHaskellDepends = [
+      pkgs.haskellPackages.pa-prelude
+      pkgs.haskellPackages.pa-label
+      pkgs.haskellPackages.pa-error-tree
+      depot.users.Profpatsch.netencode.netencode-hs
+      depot.users.Profpatsch.execline.exec-helpers-hs
+    ];
+
+    isLibrary = true;
+    license = lib.licenses.mit;
+
+
+  };
+
+
+in
+depot.nix.readTree.drvTargets {
+  inherit
+    with-args
+    rust
+    haskell
+    ;
+}