Generate a new backend for Snowpark (finos#33)

Generate empty files for ELM modules in the IR

cli/src/Morphir/Elm/Target.elm

@@ -19,6 +19,7 @@ import Morphir.SpringBoot.Backend.Codec
 import Morphir.TypeScript.Backend
 import Morphir.TypeSpec.Backend
 import Morphir.TypeSpec.Backend.Codec
+import Morphir.Snowpark.Backend
 
 
 
@@ -34,6 +35,7 @@ type BackendOptions
     | SparkOptions Morphir.Scala.Spark.Backend.Options
     | JsonSchemaOptions Morphir.JsonSchema.Backend.Options
     | TypeSpecOptions Morphir.TypeSpec.Backend.Options
+    | SnowparkOptions Morphir.Snowpark.Backend.Options
 
 
 decodeOptions : Result Error String -> Decode.Decoder BackendOptions
@@ -53,6 +55,9 @@ decodeOptions gen =
 
         Ok "Spark" ->
             Decode.map SparkOptions (Decode.succeed Morphir.Scala.Spark.Backend.Options)
+
+        Ok "Snowpark" ->
+            Decode.map SnowparkOptions (Decode.succeed Morphir.Snowpark.Backend.Options)
 
         Ok "JsonSchema" ->
             Decode.map JsonSchemaOptions Morphir.JsonSchema.Backend.Codec.decodeOptions
@@ -85,6 +90,9 @@ mapDistribution back dist =
 
         SparkOptions options ->
             Ok <| Morphir.Spark.Backend.mapDistribution options dist
+
+        SnowparkOptions options ->
+            Ok <| Morphir.Snowpark.Backend.mapDistribution options dist
 
         JsonSchemaOptions options ->
             Morphir.JsonSchema.Backend.mapDistribution options dist

src/Morphir/Snowpark/Backend.elm

@@ -0,0 +1,73 @@
+module Morphir.Snowpark.Backend exposing (..)
+
+import Dict
+import List
+import Morphir.File.FileMap exposing (FileMap)
+import Morphir.IR.Distribution as Distribution exposing (..)
+import Morphir.IR.Name as Name
+import Morphir.IR.Package as Package
+import Morphir.IR.Path exposing (Path)
+import Morphir.IR.Type exposing (Type)
+import Morphir.Scala.AST as Scala
+import Morphir.Scala.PrettyPrinter as PrettyPrinter
+import Morphir.TypeSpec.Backend exposing (mapModuleDefinition)
+
+type alias Options =
+    {}
+
+mapDistribution : Options -> Distribution -> FileMap
+mapDistribution _ distro =
+    case distro of
+        Distribution.Library packageName _ packageDef ->
+            mapPackageDefinition distro packageName packageDef
+
+
+mapPackageDefinition : Distribution -> Package.PackageName -> Package.Definition ta (Type ()) -> FileMap
+mapPackageDefinition _ packagePath packageDef =
+    let
+        generatedScala =
+            packageDef.modules
+                |> Dict.toList
+                |> List.concatMap
+                    (\( modulePath, _ ) ->
+                        mapModuleDefinition packagePath modulePath
+                    )
+    in
+    generatedScala
+        |> List.map
+            (\compilationUnit ->
+                let
+                    fileContent =
+                        compilationUnit
+                            |> PrettyPrinter.mapCompilationUnit (PrettyPrinter.Options 2 80)
+                in
+                ( ( compilationUnit.dirPath, compilationUnit.fileName ), fileContent )
+            )
+        |> Dict.fromList
+
+
+mapModuleDefinition : Package.PackageName -> Path -> List Scala.CompilationUnit
+mapModuleDefinition currentPackagePath currentModulePath =
+    let
+        ( scalaPackagePath, moduleName ) =
+            case currentModulePath |> List.reverse of
+                [] ->
+                    ( [], [] )
+
+                lastName :: reverseModulePath ->
+                    let
+                        parts =
+                            List.append currentPackagePath (List.reverse reverseModulePath)
+                    in
+                    ( parts |> (List.concat >> List.map String.toLower), lastName )
+
+        moduleUnit : Scala.CompilationUnit
+        moduleUnit =
+            { dirPath = scalaPackagePath
+            , fileName = (moduleName |> Name.toTitleCase) ++ ".scala"
+            , packageDecl = scalaPackagePath
+            , imports = []
+            , typeDecls = []
+            }
+    in
+    [ moduleUnit ]