ecl/ANNOUNCEMENT

Announcement of ECL v0.9
=========================

ECL stands for Embeddable Common-Lisp. The ECL project is an effort to
modernize Giusseppe Attardi's ECL environment to produce an
implementation of the Common-Lisp language which complies to the ANSI
X3J13 definition of the language.

ECL is currently hosted at SourceForge. The home page of the project
is http://ecls.sourceforge.net, and in it you will find source code
releases, a CVS tree and an up to date documentation.

Notes for this release
======================

Thanks to Paul F. Dietz' test suite for ANSI compatibility, a lot of
bugs have been uncovered.

In particular, the SUBTYPEP routine had to be completely reimplemented. For
that we have used ideas Henry Baker's idea of representing types as infinite
bit vectors, and translating composite operations (AND, NOT, OR, etc) into
logical operations on these bit vectors. As a result, the new SUBTYPEP
should properly handle all type specifiers, except for SATISFIES and
compound CONS types other than (CONS * *) and equivalent ones.

Many components of the ECL system rely on properties of certain symbols. For
instance, the form (PROCLAIM '(fixnum *my-special-variable*)) declares that
*MY-SPECIAL-VARIABLE* is of type FIXNUM. This information was stored, in
previous versions of ECL, using property lists. Beginning with this version
these "system" properties are stored in a separate pool (basically, a hash
table). This keey property lists entirely for the user, and also prevents
that precious information gets trashed.

The interpreter and the compiler now fully support (SETF fname) function
names. For instance, they may be now used in FLET/FLABELS forms, in compiler
macros, etc.

ECLS 0.9
========

* Errors fixed:

  - The PCL relied on the compiler to optimize certain method
    combinations. However, the native compiler is not always present,
    and therefore it is safer to use interpreted functions instead.

  - The compiler had wrong type information about CHAR-NAME &
    NAME-CHAR.

  - DOTIMES fails with negative bignums and floats.

  - LOAD-TIME-VALUE should be a special operator.

  - COPY-SYMBOL fails with uninterned symbols.

  - GENSYM and GENTEMP failed if the suffix becomes a bignum.

  - COMPILE has to generate libraries with different names for each
    function. Otherwise, when compiling a second function, the
    dlopen() loader will not load the library because it thinks it has
    it already in memory.

  - When a compound form consists only of a string, this string should
    not be interpreted as a documentation string, but as a form.

  - SYMBOL-MACROLET definitions were ignored by GET-SETF-EXPANSION.

  - DESTRUCTURING-BIND fails to interpret &WHOLE arguments.

  - The compiler might get into an infinite loop when dealing with
    compiler-macros.

  - When the functions/macros in a DLL are no longer used, and the
    garbage collector notices this, the library is properly deallocated.

  - BIT-* fails when the input is made of arrays with rank <> 1.

  - A few leaks from ECL's original garbage collector have been
    fixed. Thus, the option "--disable-boehm" at configuration time is
    again active.

  - When returning from a function, the values are stored in the
    VALUES() array. This process has to be "atomic", in the sense that
    no lisp function (cl_*, si_*, bytecodes) may be called, because
    they also try to overwrite these values. This requirement was not
    accomplished by the previous inliner.

  - CCASE forms would output no value.

  - Tags in TAGBODY should be compared with EQL so that a bignums may
    tags (Two bignums which are EQL may be not EQ!).

  - Various errors in STRING-TRIM* and *CAPITALIZE.

  - Wrong type information about NAME-CHAR, CHAR-NAME and DIGIT-CHAR
    lead to compilation errors.

  - DEFPACKAGE would ignore the value of :INTERN and, would replace
    empty :USE statements with (:USE "CL").

  - :CONC-NAME alone is not interpreted as a lack of prefix in
    structures. Furthermore, when no prefix is given, the package of
    the slot name is not honored.

  - MAP-INTO did not recognize strings and bit-vectors as vectors.

  - In WITH-PACKAGE-ITERATOR, only symbols which are accessible in the
    current package should be output, and the accesibility type returned
    should correspond to that of FIND-SYMBOL.

  - The expansion of DO/DO* would not enclose the body in a TAGBODY.

  - SLOT-EXISTS-P outputted OBJNULL when the slot did not exist.

* Errors of the interpreter:

  - CASE should use EQL to compare objects, not EQ.

  - Empty PROGN and implicit PROGNs (LAMBDA, etc) should output NIL
    instead of (VALUES). Similarly, a CASE with no matching clause
    should also output NIL.

  - A NIL in the keys position of a CASE clause can never match
    anything: (CASE () (NIL 'A) (T 'B)) => B

  - SETQ can only output one value

  - User could not have a keyword variable with name ALLOW-OTHER-KEYS,
    as in (LAMBDA (&KEY ALLOW-OTHER-KEYS) (PRINT ALLOW-OTHER-KEYS)).

  - Excesive arguments to NOT or NULL were not detected.

  - Under some circumstances, FUNCALL would not signal an error when
    a symbol naming a macro is passed as a first argument.

  - When &ALLOW-OTHER-KEYS was present in the lambda list, any
    occurrence of :ALLOW-OTHER-KEYS is ignored.

* Visible changes:

  - No "Bye" message in QUIT.

  - Function definitions from the interpreter are now remembered by
    default. This means you can now type
	     (DEFUN MY-FUNCTION (X) (COS X))
    and later on
	     (COMPILE 'MY-FUNCTION)
    If you want to save memory, use this to forget these definitions
	     (SETQ SI::*KEEP-DEFINITIONS* NIL)

  - New function SI:MKSTEMP creates an totally new empty file by
    appending a 6-characters prefix to a template supplied by the
    user.

  - COMPILE now creates all temporary files in the directory pointed
    to by the environment variable TMPDIR (Or /tmp if none). It also
    uses MKSTEMP to produce unique file names, and solve the problem
    that dlopen() cannot reload two libraries with the same name.

  - The interpreter now detects syntax errors in function calls: such
    as in (setq a ("foo")).

  - Functions remf(), remprop() and putprop() removed. Use si_rem_f,
    cl_remprop and cl_putprop instead.

  - A small optimization allows the compiler to produce smaller code
    when two functions share the same keywords (Like FIND, POSITION,
    etc).

* ANSI compatibility:

  - WITH-HASH-TABLE-ITERATOR implemented.

  - In DEFGENERIC, only SPACE and SPEED declarations were allowed.

  - The bytecodes compiler did not contemplate the possibility of
    a lambda list with &key and no keyword variables.

  - In MAKE-PATHNAME, values which are supplied (even if NIL), are not
    overwritten by the :DEFAULTS. For instance, (MAKE-PATHNAME :TYPE
    NIL :DEFAULTS "FOO.LISP") => #P"FOO"

  - INVOKE-DEBUGGER now uses the value of *DEBUGGER-HOOK*.

  - Implemented LEAST-*-NORMALIZED-*-FLOAT.

  - WITH-PACKAGE-ITERATOR implemented. LOOP clauses which iterate over
    the symbols of a package now work. Furthermore, LOOP... FOR
    PRESENT-SYMBOL... now iterates both over internal and external
    symbols, just to be conformant with other implementations.

  - COMPILE should output three values: the function itself, plus two
    flags indicating the existence of errors.

  - CONSTANTP takes two arguments, the second being an environment.

  - Implemented FUNCTION-LAMBDA-EXPRESSION (Replaces non-standard
    SI::COMPILED-FUNCTION-SOURCE).

  - Right evaluation order enforced in PUSH, PUSHNEW, PSETQ.

  - In FUNCALL, the interpreter evaluated the function form *after*
    the arguments.

  - (SETF #:GXXX), where #:GXXX is any uninterned symbol, should be a
    valid function name.

  - Symbol GC moved from the COMMON-LISP package, to SI and CL-USER.

  - DELETE-PACKAGE turns a package into an illegal object. Thus, if a
    reference to the package is around, this may cause problems.

  - *CASE and *TYPECASE now use condition & restarts for signaling errors.

  - Restarts may be associated to conditions. WITH-CONDITION-RESTART
    implemented.

  - *COMPILE-FILE-{PATHNAME,TRUENAME}* defined and used.

  - All package function now signal errors of type
    PACKAGE-ERROR. Also, when trying to operate on a locked package
    (See SI::PACKAGE-LOCK), a correctable error is signaled.

  - Errors in LOOP macro are signaled as PROGRAM-ERROR.

  - When a LOOP has a NAMED sentence, no enclosing NIL block is
    produced. Furthermore, the blocks always surround the whole of the
    code, so that (LOOP FOR A IN (RETURN :GOOD)) works.

  - Character names ("Return", "Tab", etc) now have the right case.

  - CHAR/= and CHAR-NOT-EQUAL require at least one character.

  - Implemented *PRINT-READABLY*, and the condition PRINT-NOT-READABLY.

  - Implemented type EXTENDED-CHAR.

  - Property lists are no longer used to store vital
    information. Things like SETF expansions, DEFTYPEs, etc, are now
    stored and retrieved using SI::{GET,PUT,REM}-SYSPROP. The current
    implementation is based on a hash table, which means that some
    symbols may not be garbage collected.

  - New condition types PARSE-ERROR, SIMPLE-READER-ERROR and READER-ERROR. The
    errors from the reader correspond to this later type.

  - LOOP macro now accepts LOOP-FOR-BY forms, and it better supports
    destructuring (Thanks to the CMUCL team for maintaining a reasonably
    portable LOOP!).

  - SLOT-UNBOUND now effectively signals an UNBOUND-SLOT condition.

  - In structure constructors, lambda variables should not have the
    name of slot names. This avoids problems with slots that whose
    name is also a special variable or a constant.

  - MAKE-SEQUENCE, CONCATENATE, etc (All sequence functions), now
    recognize more sequence types and also signal errors when the type
    denotes a length and the sequence does not match it.

  - COERCE recognizes more types, and also signals an error in most
    cases in which the output does not match the required type (For
    instance, (COERCE 1 '(INTEGER 2 3)).

  - Implemented ARRAY-DISPLACEMENT.

  - BOA-constructors for structures should now work as expected (Among
    other things, they now support &KEY arguments).

  - DELETE and REMOVE now accept negative values of :COUNT.

  - SHADOW should work with strings/lists of strings, instead of only
    with symbols.

  - STRUCTURE-OBJECT is now a STRUCTURE-CLASS.

  - DELETE-PACKAGE and MAKE-PACKAGE now signal the right type of errors.

  - When a handler refuses to process a condition, the remaining
    handlers are processed.

  - Both the compiler and the interpreter now properly handle function
    names of the form (SETF fname). Instead of creating an uninterened
    a symbol with the name "SETF fname", the function definition is
    stored directly as a property list.

  - In destructuring lambda lists, &WHOLE may be accompanied by a
    destructuring form.

  - In DEF{CLASS,CONDITION}, arguments to the :INITFORM option, or to
    the :DEFAULT-INITARGS option, are now properly evaluated in the
    lexical environment corresponding to the DEF{CLASS,CONDITION} form.

  - Structures may now have :TYPE (VECTOR BIT), (VECTOR CHARACTER),
    etc. That sequence type is used, rather than the general one
    (VECTOR T). (:TYPE option from slots is not used, though).