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authorArne Babenhauserheide <arne_bab@web.de>2024-03-11 06:34:52 +0100
committerLudovic Courtès <ludo@gnu.org>2024-06-01 11:50:16 +0200
commitdce65edbaf55ce8ead6c9b100b6f4059b09e0ffc (patch)
tree64da64bc594bd242266f083ab19381c4f416712d /module
parent7b92b22899a104039e232eaf2030e20e47ca1a07 (diff)
downloadguile-dce65edbaf55ce8ead6c9b100b6f4059b09e0ffc.tar.gz
Add language/wisp, Wisp tests, and SRFI-119 documentation
* doc/ref/srfi-modules.texi (srfi-119): add node * module/language/wisp.scm: New file. * module/language/wisp/spec.scm: New file. * test-suite/tests/srfi-119.test: New file. Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Diffstat (limited to 'module')
-rw-r--r--module/language/wisp.scm776
-rw-r--r--module/language/wisp/spec.scm70
2 files changed, 846 insertions, 0 deletions
diff --git a/module/language/wisp.scm b/module/language/wisp.scm
new file mode 100644
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--- /dev/null
+++ b/module/language/wisp.scm
@@ -0,0 +1,776 @@
+;;; Wisp
+
+;; Copyright (C) 2013, 2017, 2018, 2020 Free Software Foundation, Inc.
+;; Copyright (C) 2014--2023 Arne Babenhauserheide.
+;; Copyright (C) 2023 Maxime Devos <maximedevos@telenet.be>
+
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;;
+;;;; This library is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;;;; Lesser General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+;;; Commentary:
+
+;; Scheme-only implementation of a wisp-preprocessor which output a
+;; Scheme code tree to feed to a Scheme interpreter instead of a
+;; preprocessed file.
+
+;; Limitations:
+;; - in some cases the source line information is missing in backtraces.
+;; check for set-source-property!
+
+;;; Code:
+
+(define-module (language wisp)
+ #:export (wisp-scheme-read-chunk wisp-scheme-read-all
+ wisp-scheme-read-file-chunk wisp-scheme-read-file
+ wisp-scheme-read-string)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-11); for let-values
+ #:use-module (srfi srfi-9); for records
+ #:use-module (ice-9 rw); for write-string/partial
+ #:use-module (ice-9 match))
+
+;; use curly-infix by default
+(eval-when (expand load eval)
+ (read-enable 'curly-infix))
+
+
+;; Helpers to preserver source properties
+
+(define (wisp-add-source-properties-from source target)
+ "Copy the source properties from source into the target and return the target."
+ (catch #t
+ (lambda ()
+ (set-source-properties! target (source-properties source)))
+ (lambda (key . arguments)
+ #f))
+ target)
+
+(define (wisp-add-source-properties-from/when-required source target)
+ "Copy the source properties if target has none."
+ (if (null? (source-properties target))
+ (wisp-add-source-properties-from source target)
+ target))
+
+
+;; Helper functions for the indent-and-symbols data structure: '((indent token token ...) ...)
+(define make-line list)
+
+(define (line-indent line)
+ (car line))
+
+(define (line-real-indent line)
+ "Get the indentation without the comment-marker for unindented lines (-1 is treated as 0)."
+ (let ((indent (line-indent line)))
+ (if (= -1 indent)
+ 0
+ indent)))
+
+(define (line-code line)
+ "Strip the indentation markers from the beginning of the line and preserve source-properties"
+ (let ((code (cdr line)))
+ ;; propagate source properties
+ (when (not (null? code))
+ (wisp-add-source-properties-from/when-required line code))
+ code))
+
+;; literal values I need
+(define readcolon
+ (string->symbol ":"))
+
+(define wisp-uuid "e749c73d-c826-47e2-a798-c16c13cb89dd")
+;; define an intermediate dot replacement with UUID to avoid clashes.
+(define repr-dot ; .
+ (string->symbol (string-append "REPR-DOT-" wisp-uuid)))
+
+;; allow using reader additions as the first element on a line to prefix the list
+(define repr-quote ; '
+ (string->symbol (string-append "REPR-QUOTE-" wisp-uuid)))
+(define repr-unquote ; ,
+ (string->symbol (string-append "REPR-UNQUOTE-" wisp-uuid)))
+(define repr-quasiquote ; `
+ (string->symbol (string-append "REPR-QUASIQUOTE-" wisp-uuid)))
+(define repr-unquote-splicing ; ,@
+ (string->symbol (string-append "REPR-UNQUOTESPLICING-" wisp-uuid)))
+
+(define repr-syntax ; #'
+ (string->symbol (string-append "REPR-SYNTAX-" wisp-uuid)))
+(define repr-unsyntax ; #,
+ (string->symbol (string-append "REPR-UNSYNTAX-" wisp-uuid)))
+(define repr-quasisyntax ; #`
+ (string->symbol (string-append "REPR-QUASISYNTAX-" wisp-uuid)))
+(define repr-unsyntax-splicing ; #,@
+ (string->symbol (string-append "REPR-UNSYNTAXSPLICING-" wisp-uuid)))
+
+;; TODO: wrap the reader to return the repr of the syntax reader
+;; additions
+
+(define (equal-rest? chars . args)
+ (equal? chars args))
+
+(define (match-charlist-to-repr char-list)
+ (let ((chars (reverse char-list)))
+ (cond
+ ((equal-rest? chars #\.) repr-dot)
+ ((equal-rest? chars #\') repr-quote)
+ ((equal-rest? chars #\,) repr-unquote)
+ ((equal-rest? chars #\`) repr-quasiquote)
+ ((equal-rest? chars #\, #\@) repr-unquote-splicing)
+ ((equal-rest? chars #\# #\') repr-syntax)
+ ((equal-rest? chars #\# #\,) repr-unsyntax)
+ ((equal-rest? chars #\# #\`) repr-quasisyntax)
+ ((equal-rest? chars #\# #\, #\@) repr-unsyntax-splicing)
+ (else #f))))
+
+(define (wisp-read port)
+ "Wrap read to catch list prefixes: read one or several chars from PORT and return read symbols or replacement-symbols as representation for special forms."
+ (let ((prefix-maxlen 4))
+ (let longpeek ((peeked '()) (repr-symbol #f))
+ (cond
+ ((or (< prefix-maxlen (length peeked))
+ (eof-object? (peek-char port))
+ (equal? #\space (peek-char port))
+ (equal? #\newline (peek-char port)))
+ (if repr-symbol ; found a special symbol, return it.
+ repr-symbol
+ (let unpeek ((remaining peeked))
+ (cond
+ ((equal? '() remaining)
+ (read port)); let read to the work
+ (else
+ (unread-char (car remaining) port)
+ (unpeek (cdr remaining)))))))
+ (else
+ (let* ((next-char (read-char port))
+ (peeked (cons next-char peeked)))
+ (longpeek
+ peeked
+ (match-charlist-to-repr peeked))))))))
+
+
+
+(define (line-continues? line)
+ (equal? repr-dot (car (line-code line))))
+
+(define (line-only-colon? line)
+ (and
+ (equal? ":" (car (line-code line)))
+ (null? (cdr (line-code line)))))
+
+(define (line-empty-code? line)
+ (null? (line-code line)))
+
+(define (line-empty? line)
+ (and
+ ;; if indent is -1, we stripped a comment, so the line was not really empty.
+ (= 0 (line-indent line))
+ (line-empty-code? line)))
+
+(define (line-strip-continuation line)
+ (if (line-continues? line)
+ (apply make-line
+ (line-indent line)
+ (cdr (line-code line)))
+ line))
+
+(define (line-strip-indentation-marker line)
+ "Strip the indentation markers from the beginning of the line for line-finalize without propagating source-properties (those are propagated in a second step)"
+ (cdr line))
+
+(define (indent-level-reduction indentation-levels level select-fun)
+ "Reduce the INDENTATION-LEVELS to the given LEVEL and return the value selected by SELECT-FUN"
+ (let loop ((newlevels indentation-levels)
+ (diff 0))
+ (cond
+ ((= level (car newlevels))
+ (select-fun (list diff indentation-levels)))
+ ((< level (car newlevels))
+ (loop
+ (cdr newlevels)
+ (1+ diff)))
+ (else
+ (raise-exception (make-exception-from-throw 'wisp-syntax-error (list (format #f "Level ~A not found in the indentation-levels ~A." level indentation-levels))))))))
+
+(define (indent-level-difference indentation-levels level)
+ "Find how many indentation levels need to be popped off to find the given level."
+ (indent-level-reduction indentation-levels level
+ (lambda (x); get the count
+ (car x))))
+
+(define (indent-reduce-to-level indentation-levels level)
+ "Find how many indentation levels need to be popped off to find the given level."
+ (indent-level-reduction indentation-levels level
+ (lambda (x); get the levels
+ (car (cdr x)))))
+
+(define (chunk-ends-with-period currentsymbols next-char)
+ "Check whether indent-and-symbols ends with a period, indicating the end of a chunk."
+ (and (not (null? currentsymbols))
+ (equal? #\newline next-char)
+ (equal? repr-dot
+ (list-ref currentsymbols (- (length currentsymbols) 1)))))
+
+
+(define (wisp-scheme-read-chunk-lines port)
+ ;; the line number for this chunk is the line number when starting to read it
+ ;; a top-level form stops processing, so we only need to retrieve this here.
+ (define line-number (port-line port))
+ (let loop ((indent-and-symbols (list)); '((5 "(foobar)" "\"yobble\"")(3 "#t"))
+ (in-indent? #t)
+ (in-underscoreindent? (equal? #\_ (peek-char port)))
+ (in-comment? #f)
+ (currentindent 0)
+ (currentsymbols '())
+ (emptylines 0))
+ (cond
+ ((>= emptylines 2)
+ ;; the chunk end has to be checked
+ ;; before we look for new chars in the
+ ;; port to make execution in the REPL
+ ;; after two empty lines work
+ ;; (otherwise it shows one more line).
+ indent-and-symbols)
+ (else
+ (let ((next-char (peek-char port)))
+ (cond
+ ((eof-object? next-char)
+ (let ((line (apply make-line currentindent currentsymbols)))
+ (set-source-property! line 'filename (port-filename port))
+ (set-source-property! line 'line line-number)
+ (append indent-and-symbols (list line))))
+ ((and in-indent?
+ (zero? currentindent)
+ (not in-comment?)
+ (not (null? indent-and-symbols))
+ (not in-underscoreindent?)
+ (not (or (equal? #\space next-char)
+ (equal? #\newline next-char)
+ (equal? (string-ref ";" 0) next-char))))
+ (append indent-and-symbols)); top-level form ends chunk
+ ((chunk-ends-with-period currentsymbols next-char)
+ ;; the line ends with a period. This is forbidden in
+ ;; SRFI-119. Use it to end the line in the REPL without
+ ;; showing continuation dots (...).
+ (append indent-and-symbols (list (apply make-line currentindent (drop-right currentsymbols 1)))))
+ ((and in-indent? (equal? #\space next-char))
+ (read-char port); remove char
+ (loop
+ indent-and-symbols
+ #t ; in-indent?
+ #f ; in-underscoreindent?
+ #f ; in-comment?
+ (1+ currentindent)
+ currentsymbols
+ emptylines))
+ ((and in-underscoreindent? (equal? #\_ next-char))
+ (read-char port); remove char
+ (loop
+ indent-and-symbols
+ #t ; in-indent?
+ #t ; in-underscoreindent?
+ #f ; in-comment?
+ (1+ currentindent)
+ currentsymbols
+ emptylines))
+ ;; any char but whitespace *after* underscoreindent is
+ ;; an error. This is stricter than the current wisp
+ ;; syntax definition.
+ ;; TODO: Fix the definition. Better start too strict.
+ ;; FIXME: breaks on lines with only underscores which should be
+ ;; empty lines.
+ ((and in-underscoreindent? (and (not (equal? #\space next-char)) (not (equal? #\newline next-char))))
+ (raise-exception (make-exception-from-throw 'wisp-syntax-error (list "initial underscores without following whitespace at beginning of the line after" (last indent-and-symbols)))))
+ ((equal? #\newline next-char)
+ (read-char port); remove the newline
+ (let*
+ ;; distinguish pure whitespace lines and lines
+ ;; with comment by giving the former zero
+ ;; indent. Lines with a comment at zero indent
+ ;; get indent -1 for the same reason - meaning
+ ;; not actually empty.
+ ((indent
+ (cond
+ (in-comment?
+ (if (= 0 currentindent); specialcase
+ -1
+ currentindent))
+ ((not (null? currentsymbols)); pure whitespace
+ currentindent)
+ (else
+ 0)))
+ (parsedline (apply make-line indent currentsymbols))
+ (emptylines
+ (if (not (line-empty? parsedline))
+ 0
+ (1+ emptylines))))
+ (when (not (= 0 (length (line-code parsedline))))
+ ;; set the source properties to parsedline so we can try to add them later.
+ (set-source-property! parsedline 'filename (port-filename port))
+ (set-source-property! parsedline 'line line-number))
+ ;; TODO: If the line is empty. Either do it here and do not add it, just
+ ;; increment the empty line counter, or strip it later. Replace indent
+ ;; -1 by indent 0 afterwards.
+ (loop
+ (append indent-and-symbols (list parsedline))
+ #t ; in-indent?
+ (if (<= 2 emptylines)
+ #f ; chunk ends here
+ (equal? #\_ (peek-char port))); are we in underscore indent?
+ #f ; in-comment?
+ 0
+ '()
+ emptylines)))
+ ((equal? #t in-comment?)
+ (read-char port); remove one comment character
+ (loop
+ indent-and-symbols
+ #f ; in-indent?
+ #f ; in-underscoreindent?
+ #t ; in-comment?
+ currentindent
+ currentsymbols
+ emptylines))
+ ((or (equal? #\space next-char) (equal? #\tab next-char) (equal? #\return next-char)); remove whitespace when not in indent
+ (read-char port); remove char
+ (loop
+ indent-and-symbols
+ #f ; in-indent?
+ #f ; in-underscoreindent?
+ #f ; in-comment?
+ currentindent
+ currentsymbols
+ emptylines))
+ ;; | cludge to appease the former wisp parser
+ ;; | used for bootstrapping which has a
+ ;; v problem with the literal comment char
+ ((equal? (string-ref ";" 0) next-char)
+ (loop
+ indent-and-symbols
+ #f ; in-indent?
+ #f ; in-underscoreindent?
+ #t ; in-comment?
+ currentindent
+ currentsymbols
+ emptylines))
+ (else ; use the reader
+ (loop
+ indent-and-symbols
+ #f ; in-indent?
+ #f ; in-underscoreindent?
+ #f ; in-comment?
+ currentindent
+ ;; this also takes care of the hashbang and leading comments.
+ (append currentsymbols (list (wisp-read port)))
+ emptylines))))))))
+
+
+(define (line-code-replace-inline-colons line)
+ "Replace inline colons by opening parens which close at the end of the line"
+ ;; format #t "replace inline colons for line ~A\n" line
+ (let loop ((processed '())
+ (unprocessed line))
+ (cond
+ ((null? unprocessed)
+ ;; format #t "inline-colons processed line: ~A\n" processed
+ processed)
+ ;; replace : . with nothing
+ ((and (<= 2 (length unprocessed)) (equal? readcolon (car unprocessed)) (equal? repr-dot (car (cdr unprocessed))))
+ (loop
+ (append processed
+ (loop '() (cdr (cdr unprocessed))))
+ '()))
+ ((equal? readcolon (car unprocessed))
+ (loop
+ (append processed
+ (list (loop '() (cdr unprocessed))))
+ '()))
+ (else
+ (loop
+ (append processed
+ (list (car unprocessed)))
+ (cdr unprocessed))))))
+
+(define (line-replace-inline-colons line)
+ (cons
+ (line-indent line)
+ (line-code-replace-inline-colons (line-code line))))
+
+(define (line-strip-lone-colon line)
+ "A line consisting only of a colon is just a marked indentation level. We need to kill the colon before replacing inline colons."
+ (if (equal? (line-code line) (list readcolon))
+ (make-line (line-indent line))
+ line))
+
+(define (line-finalize line)
+ "Process all wisp-specific information in a line and strip it"
+ (let ((l (line-code-replace-inline-colons
+ (line-strip-indentation-marker
+ (line-strip-lone-colon
+ (line-strip-continuation line))))))
+ (when (not (null? (source-properties line)))
+ (catch #t
+ (lambda ()
+ (set-source-properties! l (source-properties line)))
+ (lambda (key . arguments)
+ #f)))
+ l))
+
+(define (wisp-propagate-source-properties code)
+ "Propagate the source properties from the sourrounding list into every part of the code."
+ (let loop ((processed '())
+ (unprocessed code))
+ (cond
+ ((and (null? processed) (not (pair? unprocessed)) (not (list? unprocessed)))
+ unprocessed)
+ ((and (pair? unprocessed) (not (list? unprocessed)))
+ (cons
+ (wisp-propagate-source-properties (car unprocessed))
+ (wisp-propagate-source-properties (cdr unprocessed))))
+ ((null? unprocessed)
+ processed)
+ (else
+ (let ((line (car unprocessed)))
+ (wisp-add-source-properties-from/when-required line unprocessed)
+ (wisp-add-source-properties-from/when-required code unprocessed)
+ (wisp-add-source-properties-from/when-required unprocessed line)
+ (wisp-add-source-properties-from/when-required unprocessed code)
+ (let ((processed (append processed (list (wisp-propagate-source-properties line)))))
+ ;; must propagate from line, because unprocessed and code can be null, then they cannot keep source-properties.
+ (wisp-add-source-properties-from/when-required line processed)
+ (loop processed
+ (cdr unprocessed))))))))
+
+(define* (wisp-scheme-indentation-to-parens lines)
+ "Add parentheses to lines and remove the indentation markers"
+ (when
+ (and
+ (not (null? lines))
+ (not (line-empty-code? (car lines)))
+ (not (= 0 (line-real-indent (car lines))))); -1 is a line with a comment
+ (if (= 1 (line-real-indent (car lines)))
+ ;; accept a single space as indentation of the first line (and ignore the indentation) to support meta commands
+ (set! lines
+ (cons
+ (cons 0 (cdr (car lines)))
+ (cdr lines)))
+ (raise-exception
+ (make-exception-from-throw
+ 'wisp-syntax-error
+ (list
+ (format #f "The first symbol in a chunk must start at zero indentation. Indentation and line: ~A"
+ (car lines)))))))
+ (let loop ((processed '())
+ (unprocessed lines)
+ (indentation-levels '(0)))
+ (let* ((current-line
+ (if (<= 1 (length unprocessed))
+ (car unprocessed)
+ (make-line 0))); empty code
+ (next-line
+ (if (<= 2 (length unprocessed))
+ (car (cdr unprocessed))
+ (make-line 0))); empty code
+ (current-indentation
+ (car indentation-levels))
+ (current-line-indentation (line-real-indent current-line)))
+ ;; format #t "processed: ~A\ncurrent-line: ~A\nnext-line: ~A\nunprocessed: ~A\nindentation-levels: ~A\ncurrent-indentation: ~A\n\n"
+ ;; . processed current-line next-line unprocessed indentation-levels current-indentation
+ (cond
+ ;; the real end: this is reported to the outside world.
+ ((and (null? unprocessed) (not (null? indentation-levels)) (null? (cdr indentation-levels)))
+ ;; reverse the processed lines, because I use cons.
+ processed)
+ ;; the recursion end-condition
+ ((and (null? unprocessed))
+ ;; this is the last step. Nothing more to do except
+ ;; for rolling up the indentation levels. return the
+ ;; new processed and unprocessed lists: this is a
+ ;; side-recursion
+ (values processed unprocessed))
+ ((null? indentation-levels)
+ (raise-exception
+ (make-exception-from-throw
+ 'wisp-programming-error
+ (list
+ "The indentation-levels are null but the current-line is null: Something killed the indentation-levels."))))
+ (else ; now we come to the line-comparisons and indentation-counting.
+ (cond
+ ((line-empty-code? current-line)
+ ;; We cannot process indentation without
+ ;; code. Just switch to the next line. This should
+ ;; only happen at the start of the recursion.
+ (loop
+ processed
+ (cdr unprocessed)
+ indentation-levels))
+ ((and (line-empty-code? next-line) (<= 2 (length unprocessed)))
+ ;; take out the next-line from unprocessed.
+ (loop
+ processed
+ (cons current-line
+ (cdr (cdr unprocessed)))
+ indentation-levels))
+ ((> current-indentation current-line-indentation)
+ ;; this just steps back one level via the side-recursion.
+ (let ((previous-indentation (car (cdr indentation-levels))))
+ (if (<= current-line-indentation previous-indentation)
+ (values processed unprocessed)
+ (begin ;; not yet used level! TODO: maybe throw an error here instead of a warning.
+ (let ((linenumber (- (length lines) (length unprocessed))))
+ (format (current-error-port) ";;; WARNING:~A: used lower but undefined indentation level (line ~A of the current chunk: ~S). This makes refactoring much more error-prone, therefore it might become an error in a later version of Wisp.\n" (source-property current-line 'line) linenumber (cdr current-line)))
+ (loop
+ processed
+ unprocessed
+ (cons ; recursion via the indentation-levels
+ current-line-indentation
+ (cdr indentation-levels)))))))
+ ((= current-indentation current-line-indentation)
+ (let ((line (line-finalize current-line))
+ (next-line-indentation (line-real-indent next-line)))
+ (cond
+ ((>= current-line-indentation next-line-indentation)
+ ;; simple recursiive step to the next line
+ (loop
+ (append processed
+ (if (line-continues? current-line)
+ line
+ (wisp-add-source-properties-from line (list line))))
+ (cdr unprocessed); recursion here
+ indentation-levels))
+ ((< current-line-indentation next-line-indentation)
+ ;; side-recursion via a sublist
+ (let-values
+ (((sub-processed sub-unprocessed)
+ (loop
+ line
+ (cdr unprocessed); recursion here
+ indentation-levels)))
+ (loop
+ (append processed (list sub-processed))
+ sub-unprocessed ; simply use the recursion from the sub-recursion
+ indentation-levels))))))
+ ((< current-indentation current-line-indentation)
+ (loop
+ processed
+ unprocessed
+ (cons ; recursion via the indentation-levels
+ current-line-indentation
+ indentation-levels)))
+ (else
+ (raise-exception
+ (make-exception-from-throw
+ 'wisp-not-implemented
+ (list
+ (format #f "Need to implement further line comparison: current: ~A, next: ~A, processed: ~A."
+ current-line next-line processed)))))))))))
+
+
+(define (wisp-scheme-replace-inline-colons lines)
+ "Replace inline colons by opening parens which close at the end of the line"
+ (let loop ((processed '())
+ (unprocessed lines))
+ (if (null? unprocessed)
+ processed
+ (loop
+ (append processed (list (line-replace-inline-colons (car unprocessed))))
+ (cdr unprocessed)))))
+
+
+(define (wisp-scheme-strip-indentation-markers lines)
+ "Strip the indentation markers from the beginning of the lines"
+ (let loop ((processed '())
+ (unprocessed lines))
+ (if (null? unprocessed)
+ processed
+ (loop
+ (append processed (cdr (car unprocessed)))
+ (cdr unprocessed)))))
+
+(define (wisp-unescape-underscore-and-colon code)
+ "replace \\_ and \\: by _ and :"
+ (wisp-add-source-properties-from/when-required
+ code
+ (cond ((list? code) (map wisp-unescape-underscore-and-colon code))
+ ((eq? code '\:) ':)
+ ;; Look for symbols like \____ and remove the \.
+ ((symbol? code)
+ (let ((as-string (symbol->string code)))
+ (if (and (>= (string-length as-string) 2) ; at least a single underscore
+ (char=? (string-ref as-string 0) #\\)
+ (string-every #\_ (substring as-string 1)))
+ (string->symbol (substring as-string 1))
+ code)))
+ (#t code))))
+
+
+(define (wisp-replace-empty-eof code)
+ "replace ((#<eof>)) by ()"
+ ;; This is a hack which fixes a bug when the
+ ;; parser hits files with only hashbang and comments.
+ (if (and (not (null? code)) (pair? (car code)) (eof-object? (car (car code))) (null? (cdr code)) (null? (cdr (car code))))
+ (wisp-add-source-properties-from code (list))
+ code))
+
+
+(define (wisp-replace-paren-quotation-repr code)
+ "Replace lists starting with a quotation symbol by
+ quoted lists."
+ (wisp-add-source-properties-from/when-required
+ code
+ (match code
+ (('REPR-QUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'quote (map wisp-replace-paren-quotation-repr a)))
+ ((a ... 'REPR-QUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd b); this is the quoted empty list
+ (append
+ (map wisp-replace-paren-quotation-repr a)
+ (list (list 'quote (map wisp-replace-paren-quotation-repr b)))))
+ (('REPR-QUASIQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd 'REPR-UNQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'quasiquote (list 'unquote (map wisp-replace-paren-quotation-repr a))))
+ (('REPR-UNQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'unquote (map wisp-replace-paren-quotation-repr a)))
+ ((a ... 'REPR-UNQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd b)
+ (append
+ (map wisp-replace-paren-quotation-repr a)
+ (list (list 'unquote (map wisp-replace-paren-quotation-repr b)))))
+ (('REPR-QUASIQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'quasiquote (map wisp-replace-paren-quotation-repr a)))
+ ((a ... 'REPR-QUASIQUOTE-e749c73d-c826-47e2-a798-c16c13cb89dd b); this is the quoted empty list
+ (append
+ (map wisp-replace-paren-quotation-repr a)
+ (list (list 'quasiquote (map wisp-replace-paren-quotation-repr b)))))
+ (('REPR-UNQUOTESPLICING-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'unquote-splicing (map wisp-replace-paren-quotation-repr a)))
+ (('REPR-SYNTAX-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'syntax (map wisp-replace-paren-quotation-repr a)))
+ (('REPR-UNSYNTAX-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'unsyntax (map wisp-replace-paren-quotation-repr a)))
+ (('REPR-QUASISYNTAX-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'quasisyntax (map wisp-replace-paren-quotation-repr a)))
+ (('REPR-UNSYNTAXSPLICING-e749c73d-c826-47e2-a798-c16c13cb89dd a ...)
+ (list 'unsyntax-splicing (map wisp-replace-paren-quotation-repr a)))
+ ;; literal array as start of a line: # (a b) c -> (#(a b) c)
+ ((#\# a ...)
+ (with-input-from-string ;; hack to defer to read
+ (string-append "#"
+ (with-output-to-string
+ (λ ()
+ (write (map wisp-replace-paren-quotation-repr a)
+ (current-output-port)))))
+ read))
+ ((a ...)
+ (map wisp-replace-paren-quotation-repr a))
+ (a
+ a))))
+
+(define (wisp-make-improper code)
+ "Turn (a #{.}# b) into the correct (a . b).
+
+read called on a single dot creates a variable named #{.}# (|.|
+in r7rs). Due to parsing the indentation before the list
+structure is known, the reader cannot create improper lists
+when it reads a dot. So we have to take another pass over the
+code to recreate the improper lists.
+
+Match is awesome!"
+ (define is-proper? #t)
+ ;; local alias
+ (define (add-prop/req form)
+ (wisp-add-source-properties-from/when-required code form))
+ (wisp-add-source-properties-from/when-required
+ code
+ (let ((improper
+ (match code
+ ((a ... b 'REPR-DOT-e749c73d-c826-47e2-a798-c16c13cb89dd c)
+ (set! is-proper? #f)
+ (wisp-add-source-properties-from/when-required
+ code
+ (append (map wisp-make-improper (map add-prop/req a))
+ (cons (wisp-make-improper (add-prop/req b))
+ (wisp-make-improper (add-prop/req c))))))
+ ((a ...)
+ (add-prop/req
+ (map wisp-make-improper (map add-prop/req a))))
+ (a
+ a))))
+ (define (syntax-error li msg)
+ (raise-exception
+ (make-exception-from-throw
+ 'wisp-syntax-error
+ (list (format #f "incorrect dot-syntax #{.}# in code: ~A: ~A" msg li)))))
+ (if is-proper?
+ improper
+ (let check ((tocheck improper))
+ (match tocheck
+ ;; lists with only one member
+ (('REPR-DOT-e749c73d-c826-47e2-a798-c16c13cb89dd)
+ (syntax-error tocheck "list with the period as only member"))
+ ;; list with remaining dot.
+ ((a ...)
+ (if (and (member repr-dot a))
+ (syntax-error tocheck "leftover period in list")
+ (map check a)))
+ ;; simple pair - this and the next do not work when parsed from wisp-scheme itself. Why?
+ (('REPR-DOT-e749c73d-c826-47e2-a798-c16c13cb89dd . c)
+ (syntax-error tocheck "dot as first element in already improper pair"))
+ ;; simple pair, other way round
+ ((a . 'REPR-DOT-e749c73d-c826-47e2-a798-c16c13cb89dd)
+ (syntax-error tocheck "dot as last element in already improper pair"))
+ ;; more complex pairs
+ ((? pair? a)
+ (let ((head (drop-right a 1))
+ (tail (last-pair a)))
+ (cond
+ ((equal? repr-dot (car tail))
+ (syntax-error tocheck "equal? repr-dot : car tail"))
+ ((equal? repr-dot (cdr tail))
+ (syntax-error tocheck "equal? repr-dot : cdr tail"))
+ ((member repr-dot head)
+ (syntax-error tocheck "member repr-dot head"))
+ (else
+ a))))
+ (a
+ a)))))))
+
+(define (wisp-scheme-read-chunk port)
+ "Read and parse one chunk of wisp-code"
+ (with-fluids ((%read-hash-procedures (fluid-ref %read-hash-procedures)))
+ (read-hash-extend #\# (lambda args #\#))
+ (let ((lines (wisp-scheme-read-chunk-lines port)))
+ (wisp-make-improper
+ (wisp-replace-empty-eof
+ (wisp-unescape-underscore-and-colon
+ (wisp-replace-paren-quotation-repr
+ (wisp-propagate-source-properties
+ (wisp-scheme-indentation-to-parens lines)))))))))
+
+(define (wisp-scheme-read-all port)
+ "Read all chunks from the given port"
+ (let loop ((tokens '()))
+ (cond
+ ((eof-object? (peek-char port))
+ tokens)
+ (else
+ (loop
+ (append tokens (wisp-scheme-read-chunk port)))))))
+
+(define (wisp-scheme-read-file path)
+ (call-with-input-file path wisp-scheme-read-all))
+
+(define (wisp-scheme-read-file-chunk path)
+ (call-with-input-file path wisp-scheme-read-chunk))
+
+(define (wisp-scheme-read-string str)
+ (call-with-input-string str wisp-scheme-read-all))
+
+(define (wisp-scheme-read-string-chunk str)
+ (call-with-input-string str wisp-scheme-read-chunk))
diff --git a/module/language/wisp/spec.scm b/module/language/wisp/spec.scm
new file mode 100644
index 000000000..f7fd794e0
--- /dev/null
+++ b/module/language/wisp/spec.scm
@@ -0,0 +1,70 @@
+;;; Language interface for Wisp in Guile
+
+;; Copyright (C) 2005--2014 by David A. Wheeler and Alan Manuel K. Gloria
+;; Copyright (C) 2014--2023 Arne Babenhauserheide.
+;; Copyright (C) 2023 Maxime Devos <maximedevos@telenet.be>
+
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;;
+;;;; This library is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+;;;; Lesser General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+;; adapted from spec.scm: https://gitorious.org/nacre/guile-sweet/?p=nacre:guile-sweet.git;a=blob;f=sweet/spec.scm;hb=ae306867e371cb4b56e00bb60a50d9a0b8353109
+
+(define-module (language wisp spec)
+ #:use-module (language wisp)
+ #:use-module (system base compile)
+ #:use-module (system base language)
+ #:use-module (language scheme compile-tree-il)
+ #:use-module (language scheme decompile-tree-il)
+ #:export (wisp))
+
+;;;
+;;; Language definition
+;;;
+
+
+(define (read-one-wisp-sexp port env)
+ ;; Allow using "# foo" as #(foo).
+ ;; Don't use the globally-acting read-hash-extend, because this
+ ;; doesn't make much sense in parenthese-y (non-Wisp) Scheme.
+ ;; Instead, use fluids to temporarily add the extension.
+ (with-fluids ((%read-hash-procedures (fluid-ref %read-hash-procedures)))
+ (read-hash-extend #\# (lambda args #\# ))
+ ;; Read Wisp files as UTF-8, to support non-ASCII characters.
+ ;; TODO: would be nice to support ';; coding: whatever' lines
+ ;; like in parenthese-y Scheme.
+ (set-port-encoding! port "UTF-8")
+ (if (eof-object? (peek-char port))
+ (read-char port) ; return eof: we’re done
+ (let ((chunk (wisp-scheme-read-chunk port)))
+ (and (not (null? chunk)) ; <---- XXX: maybe (pair? chunk)
+ (car chunk))))))
+
+(define-language wisp
+ #:title "Wisp Scheme Syntax. See SRFI-119 for details"
+ ;; . #:reader read-one-wisp-sexp
+ #:reader read-one-wisp-sexp ; : lambda (port env) : let ((x (read-one-wisp-sexp port env))) (display x)(newline) x ;
+ #:compilers `((tree-il . ,compile-tree-il))
+ #:decompilers `((tree-il . ,decompile-tree-il))
+ #:evaluator (lambda (x module) (primitive-eval x))
+ #:printer write ; TODO: backtransform to Wisp? Use source-properties?
+ #:make-default-environment
+ (lambda ()
+ ;; Ideally we'd duplicate the whole module hierarchy so that `set!',
+ ;; `fluid-set!', etc. don't have any effect in the current environment.
+ (let ((m (make-fresh-user-module)))
+ ;; Provide a separate `current-reader' fluid so that
+ ;; compile-time changes to `current-reader' are
+ ;; limited to the current compilation unit.
+ (module-define! m 'current-reader (make-fluid))
+ m)))