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

Copyright © 2016,2017,2018 Jan (janneke) 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 bug-mes@gnu.org.

* Changes in 0.19 since 0.18
** Core
*** The build system has been simplified.
*** Mes now prints a backtrace upon error.
*** Performance has been improved 2-8 times, making Mes 2-10 times slower than Guile.
*** Mes now supports a module type and uses a `boot-module'.
*** Mes now supports a hash_table type.
*** Mes now supports a struct type.
*** Mes now supports building a %bootstrap-mes seed from Guix.
** Language
*** Records are now implemented using struct (WAS: vector).
*** 44 new functions
ceil,
char-downcase,
char-set-adjoin,
char-set-complement,
char-upcase,
current-time,
delete-file,
dup,
dup2,
file-exists?,
floor,
frame-printer,
get-internal-run-time,
getcwd,
gettimeofday,
hash,
hash-ref,
hash-set!,
hash-table-printer,
hashq,
hashq-get-handle,
hashq-ref,
hashq-set,
inexact->exact,
make-hash-table,
make-stack,
make-struct,
module-define!,
module-printer,
module-ref,
module-variable,
read-line,
round,
stack-length,
stack-ref,
string-downcase,
string-tokenize,
string-upcase,
struct-length,
struct-ref,
struct-set!
struct-vtable,
struct-vtable,
with-error-to-file.
** MesCC
*** Assembly defines have been cleaned-up: duplicates deleted, missing added, wrong fixed.
*** MesCC now supports compiling Bash.
**** 6 New functions
getegid,
geteuid,
getppid,
setgid,
setuid,
sigdelset,
sigprocmask,
**** 22 New macros
EACCES,
ENOSPC,
ESPIPE,
INT16_MAX,
INT16_MIN,
INT32_MAX,
INT32_MIN,
INT64_MAX,
INT64_MIN,
INT8_MAX,
INT8_MIN,
LLONG_MAX,
LLONG_MIN,
SIZE_MAX
SYS_getegid,
SYS_geteuid,
SYS_setgid
SYS_setuid,
S_IRGRP,
S_IROTH,
S_IRWXG,
S_IRWXO
S_ISGID,
S_ISUID,
S_IWGRP,
S_IWOTH,
S_IXGRP,
S_IXOTH,
UINT16_MAX,
UINT32_MAX,
UINT64_MAX,
UINT8_MAX,
_POSIX_VERSION
** Noteworthy bug fixes
*** Mes now support \xNN in strings.  Fixes using Nyacc-0.86.0.
*** MesCC now supports the unary plus operator.
*** MesCC now supports the `U' integer suffix.
*** MesCC now comes with INTnn_MIN/MAX, UINTnn defines in stdint.h.
*** MesCC now always exits non-zero when assembler or linker fail.
* Changes in 0.18 since 0.17.1
** Core
*** Mes/MesCC now supports x86_64.
*** Mes/MesCC now brings a Reduced Binary Seed bootstrap to GuixSD.
** Language
*** fold-right now supports 3 lists.
** MesCC
*** MesCC now supports x86_64 (also as cross build), using -m 64.
*** Mes C Library now has better support for bootstrapping gcc-3.0.
*** Mes C test suite now has 178 tests; 74 tests were added.
*** MesCC has been refactored to support use an abstracted assembly language.
*** MesCC now uses Nyacc 0.86.0.
** Noteworthy bug fixes
*** scaffold/tests/7s-struct-short.c has been fixed.
* Changes in 0.17.1 since 0.17
** MesCC
*** Mes C Library has now been exploded into a separate C file per function.
*** Mes C Library now bootstraps glibc-2.16.0, binutils-2.20.1, gcc-4.7.4.
*** Mes C Library now supports compiling make-3.82.
*** Mes C Library now supports compiling diffutils-2.7.
*** Mes C Library now supports x86_64.
**** 7 new functions
chdir, clock_gettime, closedir, execl, opendir, readdir, time.
**** 5 new stubs
getlogin, setlocale, setvbuf, sigaddset, sigblock.
** Noteworthy bug fixes
*** qsort can now handle lists with duplicate entries.

* Changes in 0.17 since 0.16.1
** Core
*** GNU Mes is now an official GNU package.
*** MesCC is now installed as a regular Guile package.
*** Support --srcdir build.
*** Support all standard GNU make targets.
** MesCC
*** Mes C Lib now bootstraps glibc-2.2.5, binutils-2.20.1, gcc-4.7.4.
* Changes in 0.16.1 since 0.16
** Core
*** Mes now builds out of the box on Debian buster/testing.
*** Mes now comes with a generic build recipe: build-aux/setup-mes.sh.
*** Mes now comes with INFO documentation.
** MesCC
*** MesCC now exits if spawning BLOOD_ELF, M1, or HEX2 fails.
* Changes in 0.16 since 0.15
** Core
*** Support building with tcc, including Mes C Lib in-line assembly.
*** core:execl now supports 1000 arguments.
** MesCC
*** Mes C Lib now bootstraps glibc-2.2.5, binutils-2.20.1, gcc-4.1.0.
*** MesCC binaries now run on Linux 4.17 too, i.e. survive Linus' new `sane mmap limits.'
*** MesCC now runs with mescc-tools 0.5 (no = in long options).
**** 3 new C test
88-strrchrc, 97-fopen.c, 98-fopen.c.
** Noteworthy bug fixes
*** strrchr now stops when it reaches start of string.
*** fopen now return 0 upon failure.  Supports binutils' hack: fd=-2 means `cached'.
*** vfprintf, vsprintf now support precision and width on integers strings better.
*** fread now produces ungetc'd chars too.
*** memcmp now supports comparing 0 bytes, supporting binutils.

*** The unused ELF header data section, identical to the text section, has been removed.
* Changes in 0.15 since 0.14
** Core
*** Support fork, exec, waitpid.
*** Boot-0 loading has been refactored.
*** MesCC now has out of the box Geiser support.
** Language
*** 2 new functions
drop, drop-right.
** MesCC
*** MesCC and Mes C Lib can now build binutils-2.30, gcc-2.95.3 and glibc-2.2.5.
*** MesCC now provides dummy crti.o, crtn.o so that tcc needs not be patched for those.
*** Mes C Lib now supports compiling glibc-2.2.25.
*** Mes C Lib now supports compiling gcc-2.95.3
*** Mes C Lib now supports compiling binutils-2.30.
*** Mes C Lib now supports compiling m4-1.4.
*** Mes C Lib has been split into archs: gcc, x86-mes-gcc and x86-mes.
*** MesCC now has a posixy command line interface.
**** 70 new functions
abs, access, alarm, alloca, atexit, atol, bcmp, bcopy, brk, bzero,
chmod, clearerr, close, dup, dup2, execve, fabs, fcntl, fdgets, feof,
fgets, fileno, fork, freopen, fscanf, fstat, fsync, getcwd, getgid,
getpid, getrusage, getuid, index, ioctl, isalnum, isalpha, isascii,
iscntrl, isprint, ispunct, kill, link, lseek, lstat, mkdir, mktemp,
nanosleep, open, perror, pipe, raise, read, rename, rindex, rmdir,
sbrk, sbrk, setitimer, signal, sleep, stat, strcspn, strdup, strerror,
strncat, strpbrk, strspn, unlink, unsetenv, waitpid.
**** 23 new stubs
abort, atof, bsearch, bsearch, chown, ctime, fpurge, freadahead,
frexp, getpwnam, gmtime, mbstowcs, pclose, popen, rewind, setbuf,
sigsetmask, strftime, sys_siglist, system, times, umask, utime.
**** 10 new C tests
51-strcmp.c, 70-printf.c, 87-sscanf.c, 90-strpbrk.c, 91-fseek.c,
92-stat.c, 93-fread-fwrite.c, 94-unsetenv.c, 95-signal.c, 96-strto.c.

* Changes in 0.14 since 0.13
** Core
*** Bootstrapped Mes+MesCC  now compiles a tcc that is self-hosting and only slightly patched.
*** The reader now supports binary numbers (previously: read as decimal).
*** String port support has been moved to C.
*** The build has been simplified, the Make-in-Scheme experiment has been removed.
*** 2 new functions
chmod, logxor.
** Language
*** Mes now supports define-immutable-record-type and single set-field from srfi-9 gnu.
*** 12 new functions
basename, chmod, const, delete-duplicates, logxor, string-contains,
string-map, string-replace, string-trim, string-trim-both,
string-trim-right, unfold.
** MesCC
*** MesCC now supports standalone usage of nestedly defined enums, structs and unions.
*** MesCC now supports comparison of unsigned and promotion of signed/unsigned -> unsigned.
*** MesCC now supports sign extension for char, short.
*** MesCC now has stubbing for floats; compiling works, data is fu.
*** MesCC now has full suport for switch case, e.g. with default as first clause.
*** MesCC now supports destruction of casted expressions: ((struct foo*)p)->bar.
*** MesCC now has full support for pre/post, e.g.: (foo--)->bar and permutations.
*** MesCC now supports sizeof any expression or type.
*** MesCC now supports initialization of anonymous unions.
*** MesCC now supports bit fields.
*** MesCC now supports valued functions in expressions: destruction and dereferencing.
*** MesCC now supports function-static variables.
*** MesCC now supports initializer lists in structs and unions.
*** MesCC now has full support for heterogeneous variable declarations, e.g.: char p, *x = "foo", buf[3];
**** 4 new functions
__lshrdi3, __ashldi3, __ashrdi3, strncpy.
**** 9 new mlibc stubs
__fixdfdi, __fixsfdi, __fixunsxfdi, __fixxfdi, __floatundixf, ldexp,
strtod, strtof, strtold.
* Changes in 0.13 since 0.12
** Core
*** Bootstrapped Mes+MesCC can now compile a patched tcc in ~1h45' (~25,000 LOC).
*** MesCC scripts for Mes and Guile are now merged; executable is: `mescc'.
*** Mes now uses only one arena for stop-and-copy; doubles available size.
*** Mes now has a Guile-like command-line interface (mes.repl has been removed).
*** Mes now boots into a full Scheme by default.
*** Mes can now be compiled (MES_MINI=1) to boot into a minimal Scheme (~2000 cells).
*** Mes now creates less garbage in the reader and in
append2, append_reverse, reverse, reverse!, vector-for-each, vector-to-list, vector-map.
*** 5 new functions
append-reverse, chmod, ioctl, isatty, isspace, last_pair, reverse!.
** Language
*** 3 new functions
char-whitespace?, chmod, isatty?
** Noteworthy bug fixes
*** Two bugs in the jam scraper/garbage collector have been fixed.
*** equal2_p now uses tail call elimination.
*** Escaped characters in strings are now read and write'd correctly.
*** The repl now expands macros again.
* Changes in 0.12 since 0.11
** Core
*** Mes can now run Nyacc (0.80.42) to compile itself in ~4min (~3000 LOC).
*** Mes now recursively expands global variables per top level statement.
*** Mes now recursively expands macros per top level statement.
*** Mes now boots from MES_BOOT (default: module/mes/boot-0.scm).
*** Mes now has a full Scheme reader in C again.
This gives a 10x-20x performance improvement and increases the
bootstrap footprint by 160 LOC.
*** Mes reader now supports older abbreviated character forms
#\bel, #\bs, #\ht and #\vt.
*** 3 new functions
equal2?, memq, core:write.
** Language
*** Mes now has an incremental Scheme semantics test suite with 71 small tests.
*** Variable names can now have ticks.
*** Mes now evaluates expresions of COND only once.
*** srfi-9 records have been reimplemented.
*** #\page is now whitespace.
*** #<eof> is no longer a character.
*** 2 new macros
define-macro*, with-fluids.
*** 9 new functions
dirname, last, reverse-list->string, setenv, string-drop-right,
string-fold, string-fold-right, string-null?, write.
** MesCC
**** 9 new functions
chmod, getopt_long, ferror, itoab, longjmp, qsort, setenv, setjmp, strtol.
**** 2 new header files
endian.h, sys/signal.h.

* Changes in 0.11 since 0.10
** MesCC
*** MesCC now compiles a mes-tcc that fails 41/69 of mescc's C tests.
*** MesCC's libc can now be compiled with tcc (syscall support: write).
*** MesCC now compiles a less-patched tcc: -214/+458 lines [WAS: -333/+747].
*** MesCC now supports empty for.
*** MesCC has been greatly refactored, 500/3000 lines have been removed.
*** MesCC now supports complex [struct] by value assign foo.bar, foo->bar, foo[bar].
*** MesCC now depends on Nyacc 0.82.4.
* Changes in 0.10 since 0.9
** Core
*** 2 new functions
logand, lognot.
*** Mes now includes M1 sources for full source bootstrapping up to tcc.
** Mescc
*** Mescc now depends on Nyacc 0.81.0.
*** Mescc now compiles a mes-tcc that compiles a trivial C to a running a.out.
*** Mescc now supports several (as used my tinycc) struct by value assignments.
*** Mescc now has _start in a separate crt1.c.
*** Mescc now supports initializer arithmetic.
*** Mescc now supports arrays of struct of arbitrary size.
*** Mescc now supports pointer arithmetic.
*** Mescc now defines __i386__, __linux__.
*** Mescc now supports --*p, ++*p.
*** Mescc now supports int foo[bar] = {baz,...}.
*** Mescc now supports \x00 in strings in M1.
*** Mescc now supports complex enum expressions.  Thanks, rain1!
*** Mescc now supports short.
*** Mescc now supports foo.bar = foo.baz = bla.
*** Mescc now supports foo = bar < baz and comparison permutations.
*** Mescc now supports (anonymous) structs in unions.
*** Mescc now writes M1 strings if possible.
**** 2 improved mlibc functions
malloc, realloc.
**** 13 new mlibc functions
fclose, fgetc, fprintf, fwrite, memcpy, memmove, memset, snprintf, strcat,
strchr, strrchr, strtoull, vnsprintf.
**** 15 new tinycc-support tests
76-pointer-arithmetic.c, 77-pointer-assign.c, 78-union-struct.c,
79-int-array.c, 7a-struct-char-array.c, 7b-struct-int-array.c,
7c-dynarray.c, 7d-cast-char.c, 7e-struct-array-access.c,
7f-struct-pointer-arithmetic.c, 7g-struct-byte-word-field.c,
7h-struct-assign.c, 7i-struct-struct.c, 7j-strtoull.c,
7k-for-each-elem.c.
** Noteworthy bug fixes
*** Mescc has many fixes for foo.bar[baz], foo[bar].baz with ./-> permutations.
*** Many bugs and limitations in mescc have been fixed and removed.
* Changes in 0.9 since 0.8
** Core
*** Mes now builds better in non-Guix[SD] legacy distros/environments.  Thanks, rain1!
** Mescc
*** Mescc now compiles a modified tinycc into a running [mostly segfaulting] mes-tcc.
https://gitlab.com/janneke/tinycc branch wip-mescc.
*** Mescc now supports locals stack frame larger than 1 byte offset.
*** Mescc now supports incomplete struct initializers {0}.
*** Mescc now supports >>=, <<=, ^=, ~.
*** Mescc now supports the comma operator.
*** Mescc now supports mullti-line string initializers.
*** Mescc now supports unions.
*** Mescc now supports arrays in structs.
*** Mescc now supports structs in structs.
*** Mescc now builds and runs with Guile-2.0 (legacy distro support, Guile-2.2 recommended).
*** Mescc has been refactored to use records.
*** Mescc now bundles tinycc's test2 test suite, passes one more test [34/55 pass].
*** Mescc now has an incremental test suite consisting of 56 tests.
*** Mescc now supports stdarg variable argument lists.
*** Mescc now has __GNUC__ unset, #f (WAS: 0).
*** Mescc now depends on Nyacc 0.80.3.
*** Mescc now depends on M1 from [[https://github.com/oriansj/mescc-tools][mescc-tools]] v0.2.
*** Mescc now compiles to M1 object files.
**** 7 new mlibc functions
calloc, close, getcwd, lseek, sprintf, unlink, vprintf.
**** 31 new mlibc stubs
execvp, fclose, fdopen, fflush, fopen, fprintf, fread, free, fseek,
ftell, fwrite, localtime, longjmp, memcpy, memmove, memmove, memset,
qsort, remove, setjump, snprintf, sscanf, strchr, strrchr, strstr,
strtol, strtoll, strtoul, strtoull, time, vnsprintf.
**** 10 new header files
alloca.h, float.h, libgen.h, locale.h, stdbool.h, stddef.h, stdint.h,
stdnoreturn.h, sys/select.h, sys/wait.h.
** Noteworthy bug fixes
*** Many bugs and limitations in mescc have been fixed and removed.
* 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.
