refactor errors

bin/main.ml

@@ -1,6 +1,8 @@
 let () =
+  Logs.set_reporter (Logs.format_reporter ());
+  Logs.set_level (Some Logs.Debug);
+
   try
-    let modl = Spice.parse "fun main(x) { val y = x * 2 val z = if(y > x) y else 1 }" in
-    Format.fprintf Format.std_formatter "%a\n" Spice.Syn.pp_modl modl
-  with Spice.Error.Error err ->
-    Format.fprintf Format.err_formatter "error: %a\n" Spice.Error.pp err
+    let syn = Spice.parse "val x = 3 val y = x + 1" in
+    Fmt.pr "%a\n" Spice.Syn.pp_modl syn
+  with Spice.Error msg -> Logs.err (fun m -> m "%s" msg)

lib/error.ml

@@ -1,8 +0,0 @@
-type t = Syntax of string
-
-exception Error of t
-
-let raise_syntax_error msg = raise (Error (Syntax msg))
-
-let pp ppf = function
-  | Syntax why -> Format.fprintf ppf "syntax error: %s" why

lib/lexer.mll

@@ -1,6 +1,11 @@
 {
 open Parser
 
+exception Error of string
+
+let fail msg =
+  raise (Error msg)
+
 let keywords = Hashtbl.create 17
 let _ = begin
     Hashtbl.add keywords "true" Kw_true;
@@ -27,7 +32,7 @@ let parse_integer str =
         Buffer.add_char buffer ch)
     str;
   if Buffer.length buffer > 18 then
-    Error.raise_syntax_error "integer literal is too long";
+    fail "integer literal is too long";
   Int64.of_string (Buffer.contents buffer)
 
 let identifier str =
@@ -68,6 +73,6 @@ rule read =
   | "!="      { Binop Not_eql }
   | "."      { Dot }
   | ","      { Com }
-  | _        { Error.raise_syntax_error "unrecognized character" }
+  | _        { fail "unrecognized character" }
   | eof      { EOF }
 

lib/spice.ml

@@ -1,7 +1,15 @@
-module Error = Error
 module Syn = Syn
+module Ir = Ir
+
+exception Error of string
+
+let failf f = Fmt.kstr (fun s -> raise (Error s)) f
 
 let parse input =
   let lexbuf = Lexing.from_string input ~with_positions:true in
-  try Parser.modl Lexer.read lexbuf
-  with Parser.Error -> Error.raise_syntax_error "bad syntax"
+  try Parser.modl Lexer.read lexbuf with
+  | Parser.Error -> failf "syntax error"
+  | Lexer.Error msg -> failf "syntax error: %s" msg
+
+let compile syn =
+  try Anf_pass.anf syn with Failure msg -> failf "compilation error: %s" msg