shithub: martian9

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working on the let function

--- a/env.ml

+++ b/env.ml

@@ -1,6 +1,8 @@

 module T = Types.Types

 module Data = Map.Make (String)

+exception Runtime_error of string

+

 type env =

   { outer : env option

   ; data : Types.m9type Data.t ref

@@ -31,6 +33,6 @@

   | T.Symbol { T.value = key } ->

     (match find env sym with

     | Some found_env -> Data.find key !(found_env.data)

-    | None -> raise (Invalid_argument ("unknown symbol '" ^ key ^ "'")))

+    | None -> raise (Runtime_error ("unknown symbol '" ^ key ^ "'")))

   | _ -> raise (Invalid_argument "get: not a symbol")

 ;;

--- a/m9.ml

+++ b/m9.ml

@@ -56,11 +56,13 @@

     let sub_env = Env.make (Some env) in

     let rec bind_pairs = function

       | sym :: expr :: more ->

+         (print_endline (Printer.print sym true));

         Env.set sub_env sym (eval expr sub_env);

         bind_pairs more

-      | [ _ ] -> raise (Invalid_argument "missing 'let' body")

+      | x::[] -> raise (Reader.Syntax_error ("missing 'let' bindings (" ^ (Printer.print x true) ^ ")"))

       | [] -> ()

     in

+    print_endline ("bind_pairs:body: " ^ (Printer.print body true));

     bind_pairs bindings;

     eval body sub_env

   | T.List

@@ -81,7 +83,7 @@

             Env.set sub_env name arg;

             bind_args names args

           | [], [] -> ()

-          | _ -> raise (Invalid_argument "wrong parameter count for lambda")

+          | _ -> raise (Reader.Syntax_error "wrong parameter count for lambda")

         in

         bind_args arg_names args;

         eval expr sub_env)

@@ -98,7 +100,7 @@

     (match eval_ast ast env with

     | T.List { T.value = T.Proc { T.value = f } :: args } -> f args

     | _ as x ->

-      raise (Invalid_argument ("\"" ^ Printer.print x true ^ "\" not a function")))

+      raise (Reader.Syntax_error ("\"" ^ Printer.print x true ^ "\" not a function")))

   | _ -> eval_ast ast env

 ;;

--- a/notes.org

+++ b/notes.org

@@ -1,4 +1,5 @@

 * First things:

+** (let) doesn't work at all

 ** TODO need an "unspecified" type?

 ** TODO (display) should return unspecified

 ** TODO implement (pair)

--- a/reader.ml

+++ b/reader.ml

@@ -1,5 +1,7 @@

 module T = Types.Types

+exception Syntax_error of string

+

 let token_re =

   Str.regexp "~@\\|[][{}()'`~^@]\\|\"\\(\\\\.\\|[^\"]\\)*\"?\\|;.*\\|[^][  \n{}('\"`,;)]*"

 ;;

@@ -96,8 +98,7 @@

   let reader = read_form tokens in

   { form = Types.list [ Types.symbol sym; reader.form ]; tokens = reader.tokens }

-and read_hash all_tokens =

-  print_endline "read_hash";

+and read_vector all_tokens =

   match all_tokens with

   | [] -> raise End_of_file

   | token :: tokens ->

@@ -105,9 +106,7 @@

     | "(" ->

       let list_reader = read_list ")" { list_form = []; tokens } in

       { form = Types.vector list_reader.list_form; tokens = list_reader.tokens }

-    | _ as x ->

-      print_endline ("subtoken: " ^ x);

-      read_form tokens)

+    | _ -> read_form tokens)

 and read_form all_tokens =

   match all_tokens with

@@ -116,9 +115,7 @@

     (match token with

     | "'" -> read_quote "quote" tokens

     | "`" -> read_quote "quasiquote" tokens

-    | "#" ->

-      print_endline ("read_form:token: " ^ token);

-      read_hash tokens

+    | "#" -> read_vector tokens

     | "#|" ->

       let list_reader = read_list "|#" { list_form = []; tokens } in

       { form = T.Comment; tokens = list_reader.tokens }