Reimplement use for importing files

Author: engboris

examples/syntax.sg

@@ -113,4 +113,4 @@
 (== test ok)
 
 'import file
-'(use examples automata)
+'(use "examples/automata.sg")

src/expr.ml

@@ -172,7 +172,7 @@ let rec sgen_expr_of_expr (e : expr) : sgen_expr =
   (* linear exec *)
   | List [ Symbol k; g ] when equal_string k "linexec" ->
     Exec (true, sgen_expr_of_expr g)
-  (* linear exec *)
+  (* eval *)
   | List [ Symbol k; g ] when equal_string k "eval" ->
     Eval (sgen_expr_of_expr g)
   (* KEEP LAST -- raw constellation *)
@@ -204,6 +204,8 @@ let decl_of_expr : expr -> declaration = function
     Expect (ray_of_expr x, sgen_expr_of_expr g, const "default")
   | List [ Symbol k; x; g; m ] when equal_string k expect_op ->
     Expect (ray_of_expr x, sgen_expr_of_expr g, ray_of_expr m)
+  (* use *)
+  | List [ Symbol k; r ] when equal_string k "use" -> Use (ray_of_expr r)
   | _ -> failwith "error: invalid declaration"
 
 let program_of_expr = List.map ~f:decl_of_expr

src/lexer.ml

@@ -54,20 +54,20 @@ and string_literal lexbuf =
     match%sedlex lexbuf with
     | '"' -> STRING (Buffer.contents buffer)
     | '\\', any ->
-        let escaped =
-          match%sedlex lexbuf with
-          | 'n' -> '\n'
-          | 't' -> '\t'
-          | '\\' -> '\\'
-          | '"' -> '"'
-          | _ -> failwith "Unknown escape sequence"
-        in
-        Buffer.add_char buffer escaped;
-        loop ()
+      let escaped =
+        match%sedlex lexbuf with
+        | 'n' -> '\n'
+        | 't' -> '\t'
+        | '\\' -> '\\'
+        | '"' -> '"'
+        | _ -> failwith "Unknown escape sequence"
+      in
+      Buffer.add_char buffer escaped;
+      loop ()
     | eof -> failwith "Unterminated string literal"
     | any ->
-        Buffer.add_string buffer (Sedlexing.Utf8.lexeme lexbuf);
-        loop ()
+      Buffer.add_string buffer (Sedlexing.Utf8.lexeme lexbuf);
+      loop ()
     | _ -> failwith "Invalid character in string literal"
   in
   loop ()

src/sgen_ast.ml

@@ -40,6 +40,6 @@ type declaration =
   | Trace of sgen_expr
   | Run of sgen_expr
   | Expect of ident * sgen_expr * ident
-  | Use of ident list
+  | Use of ident
 
 type program = declaration list

src/sgen_eval.ml

@@ -238,8 +238,12 @@ let rec eval_decl ~typecheckonly ~notyping env :
       Error (ExpectError (eval_x, eval_e, message))
     else Ok env
   | Use path ->
-    let path = List.map path ~f:string_of_ray in
-    let formatted_filename = String.concat ~sep:"/" path ^ ".sg" in
+    let open Lsc_ast.StellarRays in
+    let formatted_filename : string =
+      match path with
+      | Func ((Null, f), [ s ]) when equal_string f "%string" -> string_of_ray s
+      | path -> string_of_ray path ^ ".sg"
+    in
     let lexbuf =
       Sedlexing.Utf8.from_channel (Stdlib.open_in formatted_filename)
     in