104 lines
4.4 KiB
Groff
104 lines
4.4 KiB
Groff
Subject: Mes 0.4 released
|
|
|
|
I am pleased to announce the release of Mes 0.4, representing 115
|
|
commits over barely two weeks. It now runs Nyacc and PEG and has much
|
|
reduced core.
|
|
|
|
* About
|
|
|
|
Mes aims to create an entirely source-based bootstrapping path. The
|
|
target is to [have GuixSD] boostrap from a minimal, easily inspectable
|
|
binary --that should be readable as source-- into something close to
|
|
R6RS Scheme.
|
|
|
|
As bootstrapping is presumably easiest and probably most fun with
|
|
Scheme, the next step for Mes is mescc: a C compiler/linker to
|
|
boostrap into GNU Gcc and GNU Guile, possibly via Tiny-CC.
|
|
|
|
It currently has an interpreter written in C (mes) with Garbage
|
|
Collector (Jam Scraper), a library of loadable Scheme modules--
|
|
notably Dominique Boucher's LALR[1], Pre-R6RS portable
|
|
syntax-case[2] with R7RS ellipsis, Nyacc[3] and Guile's PEG[4]
|
|
--and test suite just barely enough to support a simple REPL
|
|
(repl.mes) and a proof-of-concept C-compiler (mescc.mes) that
|
|
produces an elf from the simplest of C files.
|
|
|
|
Mes is inspired by The Maxwell Equations of Software: LISP-1.5[5]
|
|
-- John McCarthy page 13
|
|
|
|
* Download
|
|
|
|
git clone https://gitlab.com/janneke/mes
|
|
|
|
wget https://gitlab.com/janneke/mes/repository/archive.tar.gz?ref=v0.4 -O mes-0.4.tar.gz
|
|
|
|
Mes runs from the source tree and can also be built, packaged and
|
|
installed in Guix[SD] by the usual
|
|
|
|
guix package -f guix.scm
|
|
|
|
* 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 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.
|
|
|
|
|
|
Greetings,
|
|
Jan
|
|
|
|
[1] https://github.com/schemeway/lalr-scm
|
|
[2] https://www.cs.indiana.edu/chezscheme/syntax-case/old-psyntax.html
|
|
[3] https://www.nongnu.org/nyacc/
|
|
[4] https://www.gnu.org/software/guile/docs/master/guile.html/PEG-Parsing.html
|
|
[5] http://www.softwarepreservation.org/projects/LISP/book/LISP%25201.5%2520Programmers%2520Manual.pdf
|