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>?, 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