feat: add minimal TypedDataFrame housing example

cabal.project

@@ -1,3 +1,4 @@
 packages:
     .
     dataframe-fastcsv
+    examples

examples/Main.hs

@@ -1,19 +1,21 @@
 module Main where
 
-import qualified CaliforniaHousing
 import qualified Chipotle
-import qualified Iris
 import qualified OneBillionRowChallenge
+import qualified TypedHousingMini
 import System.Environment (getArgs)
 
 main :: IO ()
 main = do
     args <- getArgs
     case args of
         ["chipotle"] -> Chipotle.run
-        ["california_housing"] -> CaliforniaHousing.run
+        ["california_housing"] ->
+            putStrLn "california_housing example requires hasktorch (disabled on Windows)."
         ["one_billion_row_challenge"] -> OneBillionRowChallenge.run
-        ["iris"] -> Iris.run
+        ["iris"] ->
+            putStrLn "iris example requires hasktorch (disabled on Windows)."
+        ["typed_housing_mini"] -> TypedHousingMini.run
         _ ->
             putStrLn
-                "Usage: examples <chipotle|california_housing|one_billion_row_challenge|iris>"
+                "Usage: examples <chipotle|california_housing|one_billion_row_challenge|iris|typed_housing_mini>"

examples/TypedHousingMini.hs

@@ -0,0 +1,41 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE TypeOperators #-}
+
+module TypedHousingMini (run) where
+
+import Data.Text (Text)
+import qualified DataFrame as D
+import qualified DataFrame.Typed as T
+
+-- A small schema slice of `../data/housing.csv`.
+--
+-- NOTE: This is meant as a minimal TypedDataFrame integration example.
+-- If the CSV inference/types drift, `T.freezeWithError` will report why.
+type HousingMini =
+  '[ T.Column "median_income" Double
+   , T.Column "median_house_value" Double
+   , T.Column "ocean_proximity" Text
+   ]
+
+run :: IO ()
+run = do
+  raw <- D.readCsv "../data/housing.csv"
+  let small =
+        D.select
+          ["median_income", "median_house_value", "ocean_proximity"]
+          raw
+  case T.freezeWithError @HousingMini small of
+    Left err -> do
+      putStrLn "Failed to freeze into TypedDataFrame (schema mismatch):"
+      putStrLn (show err)
+    Right df -> do
+      putStrLn "OK: loaded TypedDataFrame slice from housing.csv"
+      print (T.nRows df)
+
+      let expensive =
+            T.filterWhere
+              (T.col @"median_house_value" T..>. T.lit 500000)
+              df
+      putStrLn ("Rows with median_house_value > 500000: " ++ show (T.nRows expensive))

examples/examples.cabal

@@ -26,9 +26,8 @@ executable examples
     ghc-options:   -O2 -threaded -rtsopts -with-rtsopts=-N
     default-extensions: Strict
     other-modules: Chipotle,
-                   CaliforniaHousing,
                    OneBillionRowChallenge,
-                   Iris,
+                   TypedHousingMini,
                    DataFrame,
                    DataFrame.Lazy,
                    DataFrame.Functions,
@@ -43,6 +42,7 @@ executable examples
                    DataFrame.Display.Terminal.PrettyPrint,
                    DataFrame.Display.Terminal.Colours,
                    DataFrame.Internal.DataFrame,
+                   DataFrame.Internal.Grouping,
                    DataFrame.Internal.Row,
                    DataFrame.Internal.Schema,
                    DataFrame.Errors,
@@ -78,7 +78,6 @@ executable examples
                    DataFrame.Lazy.Internal.Optimizer,
                    DataFrame.Lazy.Internal.Executor,
                    DataFrame.Monad,
-                   DataFrame.Hasktorch,
                    DataFrame.IO.Parquet.Seeking,
                    DataFrame.Internal.Binary,
                    DataFrame.Internal.Nullable,
@@ -95,8 +94,7 @@ executable examples
                    DataFrame.Typed.Expr,
                    DataFrame.Typed
     hs-source-dirs:   .,
-                      ../src,
-                      ../dataframe-hasktorch/src
+                      ../src
     build-depends:    base >= 4 && <5,
                       binary >= 0.8 && < 1,
                       aeson >= 0.11.0.0 && < 3,
@@ -110,7 +108,6 @@ executable examples
                       directory >= 1.3.0.0 && < 2,
                       granite ^>= 0.4,
                       hashable >= 1.2 && < 2,
-                      hasktorch,
                       http-conduit,
                       process ^>= 1.6,
                       snappy-hs ^>= 0.1,
@@ -133,6 +130,12 @@ executable examples
                       stm >= 2.5 && < 3,
                       filepath >= 1.4 && < 2,
                       Glob >= 0.10 && < 1,
+    if !os(windows)
+      other-modules: CaliforniaHousing,
+                     Iris,
+                     DataFrame.Hasktorch
+      hs-source-dirs: ../dataframe-hasktorch/src
+      build-depends: hasktorch
     if impl(ghc >= 9.12)
       build-depends: ghc-typelits-natnormalise == 0.9.3
     else