Implémentation plus simple du trait précédent: pas de changement dans

format.mli car on n'exporte rien de plus; on se contente de gérer les
fonctions de sorte que set_max_indent max_int soit équivalent à
set_max_indent pp_infinity.


git-svn-id: http://caml.inria.fr/svn/ocaml/version/3.08@6546 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/format.ml

@@ -184,10 +184,25 @@ let pp_clear_queue state =
     state.pp_left_total <- 1; state.pp_right_total <- 1;
     clear_queue state.pp_queue;;
 
-(* Large value for default tokens size. *)
-(* Could be 1073741823 that is 2^30 - 1, that is the minimal upper bound
-   of integers; now that max_int is defined, could also be max_int - 1. *)
-let pp_infinity = 1000000000;;
+(* Pp_infinity: large value for default tokens size.
+
+   Pp_infinity is documented as being greater than 1e10; to avoid
+   confusion about the word ``greater'' we shoose pp_infinity greater
+   than 1e10 + 1; for correct handling of tests in the algorithm
+   pp_infinity must be even one more than that; let's stand on the
+   safe side by choosing 1.e10+10.
+
+   Pp_infinity could probably be 1073741823 that is 2^30 - 1, that is
+   the minimal upper bound of integers; now that max_int is defined,
+   could also be defined as max_int - 1.
+
+   We must carefully double-check all the integer arithmetic
+   operations that involve pp_infinity before setting pp_infinity to
+   something around max_int: otherwise any overflow would wreck havoc
+   the pretty-printing algorithm's invariants.
+   Is it worth the burden ? *)
+
+let pp_infinity = 1000000010;;
 
 (* Output functions for the formatter. *)
 let pp_output_string state s = state.pp_output_function s 0 (String.length s)
@@ -632,11 +647,15 @@ let pp_set_ellipsis_text state s = state.pp_ellipsis <- s
 and pp_get_ellipsis_text state () = state.pp_ellipsis;;
 
 (* To set the margin of pretty-printer. *)
+let pp_limit n =
+  if n < pp_infinity then n else pred pp_infinity;;
+
 let pp_set_min_space_left state n =
-  if n >= 1 && n < pp_infinity then begin
+  if n >= 1 then
+    let n = pp_limit n in
     state.pp_min_space_left <- n;
     state.pp_max_indent <- state.pp_margin - state.pp_min_space_left;
-    pp_rinit state end;;
+    pp_rinit state;;
 
 (* Initially, we have :
   pp_max_indent = pp_margin - pp_min_space_left, and
@@ -646,7 +665,8 @@ let pp_set_max_indent state n =
 let pp_get_max_indent state () = state.pp_max_indent;;
 
 let pp_set_margin state n =
-  if n >= 1 && n < pp_infinity then begin
+  if n >= 1 then
+    let n = pp_limit n in
     state.pp_margin <- n;
     let new_max_indent =
         (* Try to maintain max_indent to its actual value. *)
@@ -658,10 +678,7 @@ let pp_set_margin state n =
          max (max (state.pp_margin - state.pp_min_space_left)
                   (state.pp_margin / 2)) 1 in
     (* Rebuild invariants. *)
-    pp_set_max_indent state new_max_indent end;;
-
-let pp_set_margin_to_max state () =
-  pp_set_margin state (pp_infinity - 1);;
+    pp_set_max_indent state new_max_indent;;
 
 let pp_get_margin state () = state.pp_margin;;
 
@@ -807,7 +824,6 @@ and set_tab = pp_set_tab std_formatter
 and print_tab = pp_print_tab std_formatter
 
 and set_margin = pp_set_margin std_formatter
-and set_margin_to_max = pp_set_margin_to_max std_formatter
 and get_margin = pp_get_margin std_formatter
 
 and set_max_indent = pp_set_max_indent std_formatter

stdlib/format.mli

@@ -162,14 +162,9 @@ val set_margin : int -> unit;;
 (** [set_margin d] sets the value of the right margin
    to [d] (in characters): this value is used to detect line
    overflows that leads to split lines.
-   Nothing happens if [d] is smaller than 2 or
-   bigger than 999999999. *)
-
-val set_margin_to_max : unit -> unit;;
-
-(** [set_margin_to_max ()] sets the value of the right margin to the
-   maximum possible value compatible with the various invariants of
-   the pretty printer. *)
+   Nothing happens if [d] is smaller than 2.
+   If [d] is too large, the right margin is set to the maximum
+   admissible value (which is greater than [10^10]). *)
 
 val get_margin : unit -> int;;
 (** Returns the position of the right margin. *)
@@ -182,13 +177,13 @@ val set_max_indent : int -> unit;;
    indentation limit to [d] (in characters):
    once this limit is reached, boxes are rejected to the left,
    if they do not fit on the current line.
-   Nothing happens if [d] is smaller than 2 or
-   bigger than 999999999. *)
+   Nothing happens if [d] is smaller than 2.
+   If [d] is too large, the limit is set to the maximum
+   admissible value (which is greater than [10^10]). *)
 
 val get_max_indent : unit -> int;;
 (** Return the value of the maximum indentation limit (in characters). *)
 
-
 (** {6 Formatting depth: maximum number of boxes allowed before ellipsis} *)
 
 val set_max_boxes : int -> unit;;
@@ -197,7 +192,7 @@ val set_max_boxes : int -> unit;;
    Material inside boxes nested deeper is printed as an
    ellipsis (more precisely as the text returned by
    [get_ellipsis_text ()]).
-   Nothing happens if [max] is not greater than 1. *)
+   Nothing happens if [max] is smaller than 2. *)
 
 val get_max_boxes : unit -> int;;
 (** Returns the maximum number of boxes allowed before ellipsis. *)
@@ -529,7 +524,6 @@ val pp_set_mark_tags : formatter -> bool -> unit;;
 val pp_get_print_tags : formatter -> unit -> bool;;
 val pp_get_mark_tags : formatter -> unit -> bool;;
 val pp_set_margin : formatter -> int -> unit;;
-val pp_set_margin_to_max : formatter -> unit -> unit;;
 val pp_get_margin : formatter -> unit -> int;;
 val pp_set_max_indent : formatter -> int -> unit;;
 val pp_get_max_indent : formatter -> unit -> int;;