simplifying

lib/logical_plan.ml

@@ -1,31 +1,17 @@
 type logical_plan =
+  | Project of logical_plan * string
   | Scan of string (* Table name *)
-  | Filter of logical_plan * condition
+  | Filter of logical_plan 
   | Join of logical_plan * Ast.join_type * logical_plan 
-and condition = 
-  | Condition of string
+  | Group of logical_plan * string list
 
-let rec generate_from_clause tables =
-  match tables with
-  | [Ast.Table(name)] -> Scan(name)
-  | [Ast.Join(left, j_type, right, _)] -> 
-      Join(
-        generate_from_clause [left],
-        j_type,
-        generate_from_clause [right]
-      )
-  | _ -> failwith "Unsupported table structure"
-
-
-let generate_logical_plan ast =
+let ast_to_logical ast =
   match ast with 
-  | Ast.Query(Select(_, Some(tables), _)) -> 
-      let base_plan = generate_from_clause tables in
-      base_plan
-  | Ast.Query(Select(_, None, _)) -> failwith "not supported"
+  | Ast.Select(_, _) -> Project(Scan("table"), "ok")
+  | _ -> failwith "Query not supported yet"
 
-(*let evaluate_plan plan =
+let rec pp_logical_plan plan =
   match plan with 
-  | Scan(table) -> 
-  | _ -> failwith "Unsupported plan"
-*)
+  | Project(plan2, name) -> pp_logical_plan plan2 ^ name
+  | _ -> "Not supported"
+

test/dune

@@ -2,6 +2,10 @@
  (name test_ast)
  (libraries parser lexer ast alcotest))
 
+(test
+ (name test_logical_plan)
+ (libraries ast logical_plan alcotest))
+
 (test
  (name test_parquet)
  (libraries parquet)

test/test_ast.ml

@@ -4,11 +4,8 @@ let parse query =
   let lexbuf = Lexing.from_string query in
   Parser.main Lexer.read_token lexbuf
 
-let equal_ast ast1 ast2 = 
-  ast1 = ast2
-
 let query_testable =
-  Alcotest.testable Ast.pp_query equal_ast
+  Alcotest.testable Ast.pp_query (=)
 
 let test_simple_select () =
   let query = "SELECT a, b FROM t" in

test/test_logical_plan.ml

@@ -0,0 +1,38 @@
+open Logical_plan
+
+let logical_plan_testable =
+  let pp_format fmt plan = 
+    Format.fprintf fmt "%s" (Logical_plan.pp_logical_plan plan)
+  in
+  Alcotest.testable pp_format (=)
+
+
+let test_simple_select () =
+  let ast1 = 
+    Ast.Select(
+      [
+        Ast.Column(
+          Ast.StringLiteral("string"),
+          None
+        )
+      ],
+      Ast.TableExpression(
+        None,
+        None,
+        None
+      )
+    )
+  in
+  let plan1 = ast_to_logical ast1 in
+  let plan2 =
+    Project(Scan("table"), "string")
+  in
+  Alcotest.(check logical_plan_testable) "ok" plan1 plan2
+
+let simple_select_set = [ ("Equals", `Quick, test_simple_select) ]
+
+let () = 
+  Alcotest.run "Logical plan tests"
+    [
+      ("Simple Selects", simple_select_set)
+    ]