lib/logical_plan.ml

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

test/dune

@@ -2,10 +2,6 @@
  (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

@@ -4,8 +4,11 @@ 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 (=)
+  Alcotest.testable Ast.pp_query equal_ast
 
 let test_simple_select () =
   let query = "SELECT a, b FROM t" in

test/test_logical_plan.ml

@@ -1,38 +0,0 @@
-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)
-    ]