Using an algebraic type for distinguishing toplevel input from location in file.

2 files changed, 17 insertions, 4 deletions

diff --git a/lib/loc.ml b/lib/loc.ml
index 9f036d90f9..06da13d44f 100644
--- a/lib/loc.ml
+++ b/lib/loc.ml
@@ -8,8 +8,12 @@
 
 (* Locations management *)
 
+type source =
+  | InFile of string
+  | ToplevelInput
+
 type t = {
-  fname : string; (** filename *)
+  fname : source; (** filename or toplevel input *)
   line_nb : int; (** start line number *)
   bol_pos : int; (** position of the beginning of start line *)
   line_nb_last : int; (** end line number *)
@@ -23,10 +27,15 @@ let create fname line_nb bol_pos bp ep = {
   line_nb_last = line_nb; bol_pos_last = bol_pos; bp = bp; ep = ep; }
 
 let make_loc (bp, ep) = {
-  fname = ""; line_nb = -1; bol_pos = 0; line_nb_last = -1; bol_pos_last = 0;
+  fname = ToplevelInput; line_nb = -1; bol_pos = 0; line_nb_last = -1; bol_pos_last = 0;
   bp = bp; ep = ep; }
 
+let mergeable loc1 loc2 =
+  loc1.fname = loc2.fname
+
 let merge loc1 loc2 =
+  if not (mergeable loc1 loc2) then
+    failwith "Trying to merge unmergeable locations.";
   if loc1.bp < loc2.bp then
     if loc1.ep < loc2.ep then {
       fname = loc1.fname;
diff --git a/lib/loc.mli b/lib/loc.mli
index 1fbaae8368..d4061e0446 100644
--- a/lib/loc.mli
+++ b/lib/loc.mli
@@ -8,8 +8,12 @@
 
 (** {5 Basic types} *)
 
+type source =
+  | InFile of string
+  | ToplevelInput
+
 type t = {
-  fname : string; (** filename *)
+  fname : source; (** filename or toplevel input *)
   line_nb : int; (** start line number *)
   bol_pos : int; (** position of the beginning of start line *)
   line_nb_last : int; (** end line number *)
@@ -22,7 +26,7 @@ type t = {
 
 (** This is inherited from CAMPL4/5. *)
 
-val create : string -> int -> int -> int -> int -> t
+val create : source -> int -> int -> int -> int -> t
 (** Create a location from a filename, a line number, a position of the
     beginning of the line, a start and end position *)