mes/NEWS

                                                              -*- org -*-
#+TITLE: Mes NEWS – history of user-visible changes
#+STARTUP: content hidestars

Copyright © 2016,2017 Jan Nieuwenhuizen <janneke@gnu.org>

  Copying and distribution of this file, with or without modification,
  are permitted in any medium without royalty provided the copyright
  notice and this notice are preserved.

Please send Mes bug reports to janneke@gnu.org.

* Changes in 0.8 since 0.7
** Mescc
*** Mescc now has experimental annotation support for hex2.
*** Mescc now depends on the hex2 linker from [[https://github.com/oriansj/MESCC_Tools][MESCC_Tools]].
Direct ELF output support has been removed.
ELF symbol and string table creation has been removed.
*** Mescc has been simplified by leveraging use labels in hex2 output.
*** Mescc now supports continue in loops.
*** Mescc now compiles to hex2 object files.
** Language
*** 1 new function
list-index.
* Changes in 0.7 since 0.6
** Core
*** The minimal C reader is now always included; dependencies
on i686-unknown-linux-gnu-gcc and binary read-0-32.mo have been
dropped, these are now optional.
** Language
*** Mes reader now supports octal numbers #oXXX.
*** 10 new functions
current-output-port, getopt-long, negate, open-output-file,
option-ref, set-current-output-port, string-rindex, string-suffix?,
with-ouwith-output-to-file, with-output-to-port.
** Mescc
*** Mescc can now be installed and used alongside a gcc installation.
*** Mescc can now handle const anywhere.
*** Mescc now supports array fields in structs.
*** Mescc now supports forward declarations and typedef.
*** Mescc can now handle comments anywhere.
*** Mescc now supports addition and substraction for enum field values.
*** Mescc now supports anonymous enums.
*** Mescc now supports all C99 header files needed to compile tcc.c.
*** build: C sources are now preprocessed separately, then compiled and linked.
*** build: mlibc and C sources are now compiled separately and then linked.
*** mlibc has been moved from Scheme snippets into C.
*** Mescc now supports -c, -D, -E, -I and -o options.
**** open now supports optional third mode parameter.
** Noteworthy bug fixes
*** string-index now supports function predicate.
*** number->string for radix > 10 now produces `a' instead of `:'.
* Changes in 0.6 since 0.5
** Core
*** configure, build now supports x86 and development for arm with-courage.
** Language
*** Nyacc has been unbundled and is now a dependency.
*** Mes now supports case-lambda.
*** Mes reader now supports abbreviated form for return character #\cr.
*** 1 new function
string-index.
** Mescc
*** Mescc can be used on regular C sources, like tinycc's tests/test2 suite.
*** make check passes 33/55 of tinycc's test suite etest/test2 tests.
*** Mescc now recognizes `short' as a type.
*** Mescc now supports sizeof (<identifier>), sizeof(<expression>).
*** Mescc now respects enum field initializers and supports enum variables.
*** Mescc now supports binary constants .
*** Mescc now supports assignments from ==, != boolean expressions .
*** Mescc now supports &, ^.
*** Mescc now supports struct pointers.
*** Mescc now supports struct definition with immediatete variable declaration.
*** Mescc now supports calling (returning correctly from) void functions.
*** Mescc now handles case statements breaks without compound correctly.
*** Mescc now has better [int/pointer] array support.
*** Mescc now has better support for simple (non-array-)structs.
*** Mescc now supports multiple declarations in one statement like: int a,b;
**** 2 new mlibc functions
printf, strcpy.
** Noteworthy bug fixes
*** Installed mes and mes.repl now also run outside of source tree again.
* Changes in 0.5 since 0.4
** Core
*** Support compilation with Mescc.
*** Support compilation with -nostdinc, -nostdlib using mlibc.
*** Support call-with-current-continuation.
*** Support exception handling, catch/throw.
*** Give sensible error message when a macro is missing.
** Language
*** Map now supports 4 lists.
*** The reader supports negative hex numbers.
*** 24 new functions
access?, assoc-set! c????r, compose, list->char-set,
open-input-string, read-string, string-delete, with-throw-handler.
** Mescc
*** Mescc can be used separately as a Nyacc-based C compiler backend for Guile.
*** Switch to Nyacc frontend, update Nyacc to 0.76.5.
*** Mescc now has a test suite, scaffold/t.c.
*** Mescc now includes a minimal C library libc/mlib.c libc/mstart.c.
*** Mescc can now compile mes.c.
** Noteworthy bug fixes
*** The build system (configure, make) has been refactored.
*** Support map-4.
*** Evaluate arguments of OR only once.
*** Fix assq-set!
*** Fix ,expand in the REPL.
    
* Changes in 0.4 since 0.3
** Core
*** Improved performance.
Macros are now memoized; after expansion and before eval'ing the
expanded form, their input s-expression is replaced by the expansion.
This yields a nice performance improvement which finally allowed
moving all non-essential bits from the C-core into Scheme...including
the reader.  The Scheme reader is much, much slower than the previous
C version, making Mes--again-- feel slow.  Think of that as a feature.
*** Bootstrap with minimal reader in C.
The C-reader needs only support reading of words and lists
(s-expressions), line-comments to read the initial [[file:module/mes/read-0.mes][Scheme reader]] which
then takes over and handles reading of quoting, characters, strings,
block-comments.
*** Reduced size.
Total C size: ~1500LOC.  The main Mes evaluator is now ~1000LOC
including cell creation and garbage collector.  This code is able to
execute a Scheme program that has been loaded into memory.  Another
~500LOC is spent to load a minimal Scheme program and to dump it, to
provide a small posix interface, math functions and do some error
reporting.
*** Programs can be dumped and loaded using --dump and --load.
** Language
*** Minimal syntactic exception support for Nyacc.
*** Minimal syntactic fluids support for Nyacc.
*** Keywords are now supported.
*** Cond now supports =>.
*** Guile's optargs: lambda* and define* are now supported.
*** #;-comments are now supported.
*** Non-nested #| |#-comments are now supported.
*** Quasisyntax is now supported.
*** R7RS syntax-rules with custom ellipsis, with-ellipsis are now supported.
*** 9 new [partial] modules
(mes fluids), (mes nyacc), (mes optargs), (mes pmatch), (mes peg),
(srfi srfi-13), (srfi srfi-9-psyntax), (srfi srfi-26), (srfi srfi-43),
(rnrs arithmetic bitwise), (sxml xpath)
*** 36 new functions
1+, 1-, abs, and=>, append-reverse, ash, char<=?, char<?, char>=?,
char>?, even?, filter, delete, delq, vector-copy, fold, fold-right,
getenv, iota, keyword->symbol list-head, list-tail, negative?, odd?,
positive?, remove!, remove, string->number, string-copy,
string-prefix?, string=, string=?, symbol->keyword symbol-append,
symbol-prefix?, unless, write, zero?.
** Noteworthy bug fixes
*** Macros are now memoized.
*** An error is reported when using a wrong number of arguments with a call.
*** Cond now evaluates its test clauses only once.
*** Append can also handle one argument.
*** For-each now supports 2 list arguments.
*** Map now supports 3 list arguments.
*** Backslash in string is supported.
*** Closure is not a pair.
*** All standard characters are supported.
*** Mescc now also runs in Guile.
* Changes in 0.3 since 0.2
** Core
*** Number-based rather than pointer-based cells.
*** Garbage collector aka Jam scraper.
A variant on SICP's stop and copy Garbage Colletor (Jam Scraper?)
algorithm has been implemented.
*** The reader has been moved to Scheme.
** Language
*** Simple loadable modules.
*** Srfi-9 and match use handwritten syntax-rules (mes-use-module (mes syntax)).
*** Optional syntax-case using psyntax (mes-use-module (mes psyntax)).
** Noteworthy bug fixes
*** Srfi-0 has been fixed.
* Changes in 0.2 since 0.1
** Core
*** Names of symbols and strings are list of characters [WAS: c-string].
*** Sc-expand from pre-R6RS's psyntax has been integrated.
*** Undefined variable error now shows the name of the undefined variable.
*** There is now only one SCM type for builtin functions.
*** Macro expansion has been cleaned-up.
** Language
*** Mes now provides a subset of R6RS.
*** Mes now provides syntax-case.
*** Mes now provides `load'.
** Noteworthy bug fixes
*** Using values as second parameter of builtin function yields first value.
*** Quoted internals (e.g. 'if 'lambda) are now symbols.
*** Syntax error now exits.
*** Make+Bash voodoo has been replaced by build-aux/mes-snarf.scm.
*** Apply now accepts multiple list arguments.
*** Apply of character, inernal, number, string is an error.
*** Quasisyntax reading 

* Changes in 0.1 (since progress report #2)
** Core
*** expand_macro is now a separate function.
*** A smaller core can now compiled using BOOT=1.
The smaller core does not provide define, define-macro, or quasiquote;
these are provided from a Scheme version of implemented eval/apply.
** Language
*** Mes now provides a subset of R5RS.
*** Mes now provides let-syntax.
*** Mes now provides match.
*** Mes now provides quasisyntax, unsyntax and unsyntax-splicing.
** User interface
*** Mes now provides a REPL, run:
    scripts/repl.mes
*** Mes compiler can be run as a script:
    scripts/mescc.mes doc/examples/main.c
*** Macro expansion can be inspected in the REPL, e.g.:
    ,expand (and 0 1)
** Noteworthy bug fixes
*** Performance: scripts/mescc.mes now takes 2s to compile main.c (was 1'20").
*** Symbols are now truly unique.
  * '(), #t, #f are no longer symbols.