bare bones haskell

.gitignore

@@ -1 +1,2 @@
 matabas-db/
+artifacts/

backend/DBConfig.hs

@@ -0,0 +1,12 @@
+{-# LANGUAGE OverloadedStrings #-}
+module DBConfig where
+
+import qualified Database.PostgreSQL.Typed as PG
+import           Network.Socket (SockAddr(SockAddrUnix))
+
+myPGDatabase :: PG.PGDatabase
+myPGDatabase = PG.defaultPGDatabase
+  { PG.pgDBAddr = Left ("localhost", "2137")
+  , PG.pgDBUser = "matabasare"
+  , PG.pgDBName = "matabas"
+  }

backend/Main.hs

@@ -0,0 +1,24 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE TemplateHaskell #-}
+
+import           Control.Exception (bracket)
+import           Control.Monad (void, unless)
+import           Data.Int (Int32)
+import           Data.Maybe (listToMaybe)
+import qualified Database.PostgreSQL.Typed as PG
+
+import DBConfig
+
+PG.useTPGDatabase myPGDatabase
+
+data Ingredient = Ingredient Int32
+  deriving (Eq)
+
+createThing :: PG.PGConnection -> Ingredient -> IO ()
+createThing pg (Ingredient product_id) =
+  void $ PG.pgExecute pg [PG.pgSQL|INSERT INTO ingredient (product_id) VALUES (${product_id})|]
+
+main = bracket (PG.pgConnect myPGDatabase) PG.pgDisconnect $ \pg -> do
+  let ing = Ingredient 10
+  createThing pg ing

buildScripts/build.sh

@@ -0,0 +1,14 @@
+set -e
+
+mkdir -p artifacts
+
+log "Kompilerar backend..."
+find backend -type f -and -name '*.hs' -print0 \
+    | xargs -0 ghc -o artifacts/Main \
+            -odir artifacts \
+            -hidir artifacts \
+            -tmpdir artifacts
+
+log "Klar" "!"
+
+set +e

buildScripts/devShellHook.sh

@@ -1,5 +1,9 @@
 set -e
 
+export PGPORT=2137
+export PGDATABASE=matabas
+export PGUSER=matabasare
+
 log() {
     printf "\e[1m\e[38;5;87m==>\e[0m\e[1m %s%s\e[0m\n" "$1" "${2:-.}"
 }
@@ -12,7 +16,7 @@ exitHook() {
 log "Letar efter existerande brevekorresmapp"
 [ -d ./matabas-db ] || {
   log "Finns ej, skapar brevekorresmapp (./matabas-db)"
-  pg_ctl initdb --pgdata=./matabas-db
+  pg_ctl initdb --pgdata=./matabas-db -o "--username=$PGUSER"
 }
 
 [ -f matabas-db/matabas.log ] && {
@@ -22,39 +26,24 @@ log "Letar efter existerande brevekorresmapp"
 }
 
 log "Startar brevekorren"
-pg_ctl start --pgdata=./matabas-db --log=./matabas-db/matabas.log --options="-p 2137 -k /tmp"
+pg_ctl start --pgdata=./matabas-db --log=./matabas-db/matabas.log --options="-p $PGPORT -k /tmp"
 trap exitHook EXIT
 
 log "Skapar matabas"
-createdb -p 2137 matabas 2>>./matabas-db/matabas.log || log "Matabasen finns, skriver ej över"
+createdb -p "$PGPORT" matabas 2>>./matabas-db/matabas.log || log "Matabasen finns, skriver ej över"
 
-log "Försvensknar miljön"
-_cargo() {
-    cuh="$1"
-    shift
-    case "$cuh" in
-        kör|spring)
-            cargo run "$@"
-            ;;
-        ny)
-            cargo new "$@"
-            ;;
-        pröva)
-            cargo test "$@"
-            ;;
-        bygg)
-            cargo build "$@"
-            ;;
-        enna)
-            cargo init "$@"
-            ;;
-        *)
-            echo "vafan gö du"
-            ;;
-    esac
+log "Ställer in schema.sql"
+psql -p "$PGPORT" "$PBDATABASE" < schema.sql
+
+P="$PWD"
+clean() {
+    log "Rensar byggnad"
+    rm -rf artifacts
+}
+
+build() {
+    source "$P/buildScripts/build.sh"
 }
-alias 'last=_cargo'
-alias cargo=exit
 
 log "Redo" "!"
 

flake.nix

@@ -14,8 +14,12 @@
           default = pkgs.hello;
         };
         devShells.default = pkgs.mkShell {
-          packages = [ packages.default pkgs.postgresql_15_jit pkgs.cargo ];
-          shellHook = builtins.readFile ./build/devShellHook.sh ;
+          packages = [
+            packages.default
+            pkgs.postgresql_15_jit
+            ( pkgs.ghc.withPackages (ps: with ps; [ scotty postgresql-typed ]) )
+          ];
+          shellHook = builtins.readFile ./buildScripts/devShellHook.sh ;
         };
       }
     ) // {

schema.sql

@@ -0,0 +1,11 @@
+CREATE TABLE IF NOT EXISTS ingredient
+  ( product_id INTEGER NOT NULL PRIMARY KEY -- https://handlaprivatkund.ica.se/stores/1004247/api/v4/products/bop?retailerProductId=...
+  );
+
+CREATE TABLE IF NOT EXISTS ingredient_data
+  ( product_id INTEGER REFERENCES ingredient(product_id)
+  , name TEXT NOT NULL
+  , cost_per_kg REAL NOT NULL
+  , cost_per_unit REAL NOT NULL
+  , image BYTEA NOT NULL
+  );