OCaml 3.12.0+rc1

Dear OCaml users,

The release of OCaml 3.12.0 is imminent.  We have made a release =
candidate
3.12.0+rc1, available as source code at this address:
  http://caml.inria.fr/pub/distrib/ocaml-3.12/

Unless there is any show-stopping bug, this will become 3.12.0 next =
week,
so you'd better test it and report any problems with compilation and
installation on your favorite platform.

-- Damien Doligez for the OCaml team


Objective Caml 3.12.0:
----------------------

(Changes that can break existing programs are marked with a "*"  )

Language features:
- Shorthand notation for records: in expressions and patterns,
    { lbl } stands for { lbl =3D lbl } and { M.lbl } for { M.lbl =3D lbl =
}
- Record patterns of the form { lbl =3D pat; _ } to mark that not all
  labels are listed, purposefully.  (See new warning below.)
- Explicit naming of a generic type; in an expression
  "fun ... (type t) ... -> e", the type t is considered abstract in its
  scope (the arguments that follow it and the body of the function),
  and then replaced by a fresh type variable. In particular, the type
  t can be used in contexts where a type variable is not allowed
  (e.g. for defining an exception in a local module).
- Explicit polymorphic types and polymorphic recursion. In let
  definitions, one can write an explicit polymorphic type just
  immediately the function name; the polymorphism will be enforced,
  and recursive calls may use the polymorphism.
  The syntax is the same as for polymorphic methods:
    "let [rec] <ident> : 'a1 ... 'an. <typexp> =3D ..."
- First-class packages modules.
  New kind of type expression, for packaged modules: (module PT).
  New kind of expression, to pack a module as a first-class value:
    (module MODEXPR : PT).
  New kind of module expression, to unpack a first-class value as a =
module:
    (val EXPR : PT).
  PT is a package type of the form "S" or
  "S with type t1 =3D ... and ... and type tn =3D ..." (S refers to a =
module type).
- Local opening of modules in a subexpression.
  Syntax: "let open M in e", or "M.(e)"
- In class definitions, method and instance variable override can now
  be made explicit, by writing "method!", "val!" or "inherit!" in place =
of
  "method", "val" and "inherit". It is an error to override an
  undefined member (or to use overriding inheritance when nothing get
  overridden). Additionally, these constructs disactivate respectively
  warnings 7 (method override, code 'M') and 13 (instance variable
  override, code 'V'). Note that, by default, warning 7 is inactive
  and warning 13 is active.
- "Destructive" substitution in signatures.
  By writing "<signature> with type t :=3D <typeconstr>" and
  "<signature> with module M :=3D <module-path>" one replaces "t" and =
"M"
  inside the signature, removing their respective fields. Among other
  uses, this allows to merge two signatures containing identically
  named fields.
* While fixing PR#4824, also corrected a gaping hole in the type =
checker,
  which allowed instantiating separately object parameters and instance
  variables in an interface. This hole was here since the beginning of
  ocaml, and as a result many programs using object inheritance in a non
  trivial way will need to be corrected. You can look at lablgtk2 for an
  example.

Compilers and toplevel:
- Warnings are now numbered and can be switched on and off individually.
  The old system with letters referring to sets of warnings is still
  supported.
- New warnings:
  + 9 (code 'R') to signal record patterns without "; _" where
    some labels of the record type are not listed in the pattern.
  + 28 when giving a wildcard argument to a constant constructor in
    a pattern-matching.
  + 29 when an end-of-line appears unescaped in a string constant.
  + 30 when the same constructor or record field is defined twice in
    mutually-recursive type definitions.
* The semantics of warning 7 (code 'M', method override) have changed
  (it now detects all overrides, not just repeated definitions inside
  the same class body), and it is now inactive by default.
- Better error report in case of unbound qualified identifier: if the =
module
  is unbound this error is reported in the first place.
- Added option '-strict-sequence' to force left hand part of sequence to =
have
  type unit.
- Added option '-no-app-funct' to turn applicative functors off.
  This option can help working around mysterious type incompatibilities
  caused by the incomplete comparison of applicative paths F(X).t.

Native-code compiler:
- AMD64: shorter and slightly more efficient code generated for=20
  float comparisons.

Standard library:
- Format: new function ikfprintf analoguous to ifprintf with a =
continuation
  argument.
* PR#4210, #4245: stricter range checking in string->integer conversion
  functions (int_of_string, Int32.of_string, Int64.of_string,
  Nativeint.of_string).  The decimal string corresponding to
  max_int + 1 is no longer accepted.
- Scanf: to prevent confusion when mixing Scanf scanning functions and =
direct
  low level input, value Scanf.stdin has been added.
* Random: changed the algorithm to produce better randomness.  Now =
passes the
  DieHard tests.
- Map: implement functions from Set that make sense for Map.

Other libraries:
* Str: letters that constitute a word now include digits 0-9 and
  underscore _.  This changes the interpretation of '\b' (word boundary)
  in regexps, but is more consistent with other regexp libraries. =
(PR#4874).

Ocamlbuild:
- Add support for native dynlink.

New tool:
- ocamlobjinfo: displays various information, esp. dependencies, for
  compiled OCaml files (.cmi, .cmo, .cma, .cmx, .cmxa, .cmxs, and =
bytecode
  executables).  Extends and makes more official the old objinfo tool
  that was installed by some OCaml packages.

All tools:
- PR#4857: add a -vnum option to display the version number and nothing =
else

Bug Fixes:
- PR#4012: Map.map and Map.mapi do not conform to specification
- PR#4478: better error messages for type definition mismatches
- PR#4683: labltk script uses fixed path on windows
- PR#4742: finalisation function raising an exception blocks other =
finalisations
- PR#4775: compiler crash on crazy types (temporary fix)
- PR#4824: narrowing the type of class parameters with a module =
specification
- PR#4862: relaxed value restriction and records
- PR#4884: optional arguments do not work when Some is redefined
- PR#4964: parenthesized names for infix functions in annot files
- PR#4970: better error message for instance variables
- PR#4975: spelling mistakes
- PR#4988: contravariance lost with ocamlc -i
- PR#5004: problem in Buffer.add_channel with very large lengths.
- PR#5008: on AMD64/MSVC port, rare float corruption during GC.
- PR#5018: wrong exception raised by Dynlink.loadfile.
- PR#5057: fatal typing error with local module + functor + polymorphic =
variant
- Wrong type for Obj.add_offset.
- Small problem with the representation of Int32, Int64, and Nativeint =
constants.
- Use RTLD_LOCAL for native dynlink in private mode.

_______________________________________________
Caml-announce mailing list
[email protected]
http://yquem.inria.fr/cgi-bin/mailman/listinfo/caml-announce