974b04ab80
Perhaps due to their staged nature, packages tend to be ‘lopsided’: deeply
nested, with the most elaborate code on the {build,right-hand-,in}side, in
snippets and phases.
When we indent outer forms too eagerly, we can easily run short on
columns by the time we get to the build code, reducing readability. A
few strategically-placed newlines early on can make a big difference.
* guix/read-print.scm (%newline-forms): Add a newline after opening a
<package> source field or an argument list. Compensate by removing the
base32 special case, which is now unnecessary.
822 lines
29 KiB
Scheme
822 lines
29 KiB
Scheme
;;; GNU Guix --- Functional package management for GNU
|
||
;;; Copyright © 2021-2023 Ludovic Courtès <ludo@gnu.org>
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;;;
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;;; This file is part of GNU Guix.
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||
;;;
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;;; GNU Guix is free software; you can redistribute it and/or modify it
|
||
;;; under the terms of the GNU General Public License as published by
|
||
;;; the Free Software Foundation; either version 3 of the License, or (at
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;;; your option) any later version.
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||
;;;
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||
;;; GNU Guix 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
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||
;;; GNU General Public License for more details.
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;;;
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;;; You should have received a copy of the GNU General Public License
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;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
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(define-module (guix read-print)
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#:use-module (ice-9 control)
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#:use-module (ice-9 match)
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#:use-module (ice-9 rdelim)
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#:use-module (ice-9 vlist)
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#:use-module (srfi srfi-1)
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#:use-module (srfi srfi-26)
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#:use-module (srfi srfi-34)
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#:use-module (srfi srfi-35)
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#:use-module (guix i18n)
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#:use-module ((guix diagnostics)
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#:select (formatted-message
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&fix-hint &error-location
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location))
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#:export (pretty-print-with-comments
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pretty-print-with-comments/splice
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read-with-comments
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read-with-comments/sequence
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object->string*
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blank?
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vertical-space
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vertical-space?
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vertical-space-height
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canonicalize-vertical-space
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page-break
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||
page-break?
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||
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comment
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comment?
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comment->string
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comment-margin?
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canonicalize-comment))
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;;; Commentary:
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;;;
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;;; This module provides a comment-preserving reader and a comment-preserving
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;;; pretty-printer smarter than (ice-9 pretty-print).
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;;;
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;;; Code:
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;;;
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;;; Comment-preserving reader.
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;;;
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(define <blank>
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;; The parent class for "blanks".
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(make-record-type '<blank> '()
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(lambda (obj port)
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(format port "#<blank ~a>"
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(number->string (object-address obj) 16)))
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#:extensible? #t))
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(define blank? (record-predicate <blank>))
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(define <vertical-space>
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(make-record-type '<vertical-space> '(height)
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#:parent <blank>
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#:extensible? #f))
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(define vertical-space? (record-predicate <vertical-space>))
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(define vertical-space (record-type-constructor <vertical-space>))
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(define vertical-space-height (record-accessor <vertical-space> 'height))
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(define canonicalize-vertical-space
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(let ((unit (vertical-space 1)))
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(lambda (space)
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"Return a vertical space corresponding to a single blank line."
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unit)))
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(define <page-break>
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(make-record-type '<page-break> '()
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#:parent <blank>
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#:extensible? #f))
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(define page-break? (record-predicate <page-break>))
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(define page-break
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(let ((break ((record-type-constructor <page-break>))))
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(lambda ()
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break)))
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(define <comment>
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;; Comments.
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(make-record-type '<comment> '(str margin?)
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#:parent <blank>
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#:extensible? #f))
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(define comment? (record-predicate <comment>))
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(define string->comment (record-type-constructor <comment>))
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(define comment->string (record-accessor <comment> 'str))
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(define comment-margin? (record-accessor <comment> 'margin?))
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(define* (comment str #:optional margin?)
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"Return a new comment made from STR. When MARGIN? is true, return a margin
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comment; otherwise return a line comment. STR must start with a semicolon and
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end with newline, otherwise an error is raised."
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(when (or (string-null? str)
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(not (eqv? #\; (string-ref str 0)))
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(not (string-suffix? "\n" str)))
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(raise (condition
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(&message (message "invalid comment string")))))
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(string->comment str margin?))
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(define char-set:whitespace-sans-page-break
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;; White space, excluding #\page.
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(char-set-difference char-set:whitespace (char-set #\page)))
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(define (space? chr)
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"Return true if CHR is white space, except for page breaks."
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(char-set-contains? char-set:whitespace-sans-page-break chr))
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(define (read-vertical-space port)
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"Read from PORT until a non-vertical-space character is met, and return a
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single <vertical-space> record."
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(let loop ((height 1))
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(match (read-char port)
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(#\newline (loop (+ 1 height)))
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((? eof-object?) (vertical-space height))
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((? space?) (loop height))
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(chr (unread-char chr port) (vertical-space height)))))
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(define (read-until-end-of-line port)
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"Read white space from PORT until the end of line, included."
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(let loop ()
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(match (read-char port)
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(#\newline #t)
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((? eof-object?) #t)
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((? space?) (loop))
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(chr (unread-char chr port)))))
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(define* (read-with-comments port #:key (blank-line? #t))
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"Like 'read', but include <blank> objects when they're encountered. When
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BLANK-LINE? is true, assume PORT is at the beginning of a new line."
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;; Note: Instead of implementing this functionality in 'read' proper, which
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;; is the best approach long-term, this code is a layer on top of 'read',
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;; such that we don't have to rely on a specific Guile version.
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(define dot (list 'dot))
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(define (dot? x) (eq? x dot))
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(define (missing-closing-paren-error)
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(raise (make-compound-condition
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(formatted-message (G_ "unexpected end of file"))
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(condition
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(&error-location
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(location (match (port-filename port)
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(#f #f)
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(file (location file
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(port-line port)
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(port-column port))))))
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(&fix-hint
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(hint (G_ "Did you forget a closing parenthesis?")))))))
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(define (reverse/dot lst)
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;; Reverse LST and make it an improper list if it contains DOT.
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(let loop ((result '())
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(lst lst))
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(match lst
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(() result)
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(((? dot?) . rest)
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(if (pair? rest)
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(let ((dotted (reverse rest)))
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(set-cdr! (last-pair dotted) (car result))
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dotted)
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(car result)))
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((x . rest) (loop (cons x result) rest)))))
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(let loop ((blank-line? blank-line?)
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(return (const 'unbalanced)))
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(match (read-char port)
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((? eof-object? eof)
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eof) ;oops!
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(chr
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(cond ((eqv? chr #\newline)
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(if blank-line?
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(read-vertical-space port)
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(loop #t return)))
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((eqv? chr #\page)
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;; Assume that a page break is on a line of its own and read
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;; subsequent white space and newline.
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(read-until-end-of-line port)
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(page-break))
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((char-set-contains? char-set:whitespace chr)
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(loop blank-line? return))
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((memv chr '(#\( #\[))
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(let/ec return
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(let liip ((lst '()))
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(define item
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(loop (match lst
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(((? blank?) . _) #t)
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(_ #f))
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(lambda ()
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(return (reverse/dot lst)))))
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(if (eof-object? item)
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(missing-closing-paren-error)
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(liip (cons item lst))))))
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((memv chr '(#\) #\]))
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(return))
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((eq? chr #\')
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(list 'quote (loop #f return)))
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((eq? chr #\`)
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(list 'quasiquote (loop #f return)))
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((eq? chr #\#)
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(match (read-char port)
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(#\~ (list 'gexp (loop #f return)))
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(#\$ (list (match (peek-char port)
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(#\@
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(read-char port) ;consume
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'ungexp-splicing)
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(_
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'ungexp))
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(loop #f return)))
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(#\+ (list (match (peek-char port)
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(#\@
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(read-char port) ;consume
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'ungexp-native-splicing)
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(_
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'ungexp-native))
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(loop #f return)))
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(chr
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(unread-char chr port)
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(unread-char #\# port)
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(read port))))
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((eq? chr #\,)
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(list (match (peek-char port)
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(#\@
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(read-char port)
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'unquote-splicing)
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(_
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'unquote))
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(loop #f return)))
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((eqv? chr #\;)
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(unread-char chr port)
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(string->comment (read-line port 'concat)
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(not blank-line?)))
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(else
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(unread-char chr port)
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(match (read port)
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((and token '#{.}#)
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(if (eq? chr #\.) dot token))
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(token token))))))))
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(define (read-with-comments/sequence port)
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"Read from PORT until the end-of-file is reached and return the list of
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expressions and blanks that were read."
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(let loop ((lst '())
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(blank-line? #t))
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(match (read-with-comments port #:blank-line? blank-line?)
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((? eof-object?)
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(reverse! lst))
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((? blank? blank)
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(loop (cons blank lst) #t))
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(exp
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(loop (cons exp lst) #f)))))
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;;;
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;;; Comment-preserving pretty-printer.
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;;;
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(define-syntax vhashq
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(syntax-rules (quote)
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((_) vlist-null)
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((_ (key (quote (lst ...))) rest ...)
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(vhash-consq key '(lst ...) (vhashq rest ...)))
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((_ (key value) rest ...)
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(vhash-consq key '((() . value)) (vhashq rest ...)))))
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(define %special-forms
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;; Forms that are indented specially. The number is meant to be understood
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;; like Emacs' 'scheme-indent-function' symbol property. When given an
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;; alist instead of a number, the alist gives "context" in which the symbol
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;; is a special form; for instance, context (modify-phases) means that the
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;; symbol must appear within a (modify-phases ...) expression.
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(vhashq
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('begin 1)
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('case 2)
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('cond 1)
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('lambda 2)
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('lambda* 2)
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('match-lambda 1)
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('match-lambda* 1)
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('define 2)
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('define* 2)
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('define-public 2)
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('define*-public 2)
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('define-syntax 2)
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('define-syntax-rule 2)
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('define-module 2)
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('define-gexp-compiler 2)
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('define-record-type 2)
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('define-record-type* 4)
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('define-configuration 2)
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('package/inherit 2)
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('let 2)
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('let* 2)
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('letrec 2)
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('letrec* 2)
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('match 2)
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('match-record 3)
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('match-record-lambda 2)
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('when 2)
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('unless 2)
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('package 1)
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('origin 1)
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('channel 1)
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('modify-inputs 2)
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('modify-phases 2)
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('add-after '(((modify-phases) . 3)))
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('add-before '(((modify-phases) . 3)))
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('replace '(((modify-phases) . 2))) ;different from 'modify-inputs'
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('substitute* 2)
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('substitute-keyword-arguments 2)
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('call-with-input-file 2)
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('call-with-output-file 2)
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||
('with-output-to-file 2)
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||
('with-input-from-file 2)
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('with-directory-excursion 2)
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('wrap-program 2)
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('wrap-script 2)
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||
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||
;; (gnu system) and (gnu services).
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('operating-system 1)
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('bootloader-configuration 1)
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('mapped-device 1)
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('file-system 1)
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('swap-space 1)
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||
('user-account 1)
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('user-group 1)
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('setuid-program 1)
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('modify-services 2)
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;; (gnu home).
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('home-environment 1)))
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||
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||
(define %newline-forms
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;; List heads that must be followed by a newline. The second argument is
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;; the context in which they must appear. This is similar to a special form
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;; of 1, except that indent is 1 instead of 2 columns.
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(vhashq
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('source '(package))
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('git-reference '(uri origin source))
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('sha256 '(origin source package))
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('arguments '(package))
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('list '(arguments package))
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||
('search-paths '(package))
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('native-search-paths '(package))
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('search-path-specification '())
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||
|
||
('services '(operating-system))
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('set-xorg-configuration '())
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||
('services '(home-environment))
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('home-bash-configuration '(service))
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||
('introduction '(channel))))
|
||
|
||
(define (prefix? candidate lst)
|
||
"Return true if CANDIDATE is a prefix of LST."
|
||
(let loop ((candidate candidate)
|
||
(lst lst))
|
||
(match candidate
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||
(() #t)
|
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((head1 . rest1)
|
||
(match lst
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(() #f)
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||
((head2 . rest2)
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(and (equal? head1 head2)
|
||
(loop rest1 rest2))))))))
|
||
|
||
(define (special-form-lead symbol context)
|
||
"If SYMBOL is a special form in the given CONTEXT, return its number of
|
||
arguments; otherwise return #f. CONTEXT is a stack of symbols lexically
|
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surrounding SYMBOL."
|
||
(match (vhash-assq symbol %special-forms)
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||
(#f #f)
|
||
((_ . alist)
|
||
(any (match-lambda
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((prefix . level)
|
||
(and (prefix? prefix context) (- level 1))))
|
||
alist))))
|
||
|
||
(define (newline-form? symbol context)
|
||
"Return true if parenthesized expressions starting with SYMBOL must be
|
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followed by a newline."
|
||
(let ((matches (vhash-foldq* cons '() symbol %newline-forms)))
|
||
(find (cut prefix? <> context)
|
||
matches)))
|
||
|
||
(define (escaped-string str)
|
||
"Return STR with backslashes and double quotes escaped. Everything else, in
|
||
particular newlines, is left as is."
|
||
(list->string
|
||
`(#\"
|
||
,@(string-fold-right (lambda (chr lst)
|
||
(match chr
|
||
(#\" (cons* #\\ #\" lst))
|
||
(#\\ (cons* #\\ #\\ lst))
|
||
(_ (cons chr lst))))
|
||
'()
|
||
str)
|
||
#\")))
|
||
|
||
(define %natural-whitespace-string-forms
|
||
;; When a string has one of these forms as its parent, only double quotes
|
||
;; and backslashes are escaped; newlines, tabs, etc. are left as-is.
|
||
'(synopsis description G_ N_))
|
||
|
||
(define (printed-string str context)
|
||
"Return the read syntax for STR depending on CONTEXT."
|
||
(define (preserve-newlines? str)
|
||
(and (> (string-length str) 40)
|
||
(string-index str #\newline)))
|
||
|
||
(match context
|
||
(()
|
||
(if (preserve-newlines? str)
|
||
(escaped-string str)
|
||
(object->string str)))
|
||
((head . _)
|
||
(if (or (memq head %natural-whitespace-string-forms)
|
||
(preserve-newlines? str))
|
||
(escaped-string str)
|
||
(object->string str)))))
|
||
|
||
(define (string-width str)
|
||
"Return the \"width\" of STR--i.e., the width of the longest line of STR."
|
||
(apply max (map string-length (string-split str #\newline))))
|
||
|
||
(define (canonicalize-comment comment indent)
|
||
"Canonicalize COMMENT, which is to be printed at INDENT, ensuring it has the
|
||
\"right\" number of leading semicolons."
|
||
(if (zero? indent)
|
||
comment ;leave top-level comments unchanged
|
||
(let ((line (string-trim-both
|
||
(string-trim (comment->string comment) (char-set #\;)))))
|
||
(string->comment (string-append
|
||
(if (comment-margin? comment)
|
||
";"
|
||
(if (string-null? line)
|
||
";;" ;no trailing space
|
||
";; "))
|
||
line "\n")
|
||
(comment-margin? comment)))))
|
||
|
||
(define %not-newline
|
||
(char-set-complement (char-set #\newline)))
|
||
|
||
(define (print-multi-line-comment str indent port)
|
||
"Print to PORT STR as a multi-line comment, with INDENT spaces preceding
|
||
each line except the first one (they're assumed to be already there)."
|
||
|
||
;; While 'read-with-comments' only returns one-line comments, user-provided
|
||
;; comments might span multiple lines, which is why this is necessary.
|
||
(let loop ((lst (string-tokenize str %not-newline)))
|
||
(match lst
|
||
(() #t)
|
||
((last)
|
||
(display last port)
|
||
(newline port))
|
||
((head tail ...)
|
||
(display head port)
|
||
(newline port)
|
||
(display (make-string indent #\space) port)
|
||
(loop tail)))))
|
||
|
||
(define %integer-forms
|
||
;; Forms that take an integer as their argument, where said integer should
|
||
;; be printed in base other than decimal base.
|
||
(letrec-syntax ((vhashq (syntax-rules ()
|
||
((_) vlist-null)
|
||
((_ (key value) rest ...)
|
||
(vhash-consq key value (vhashq rest ...))))))
|
||
(vhashq
|
||
('chmod 8)
|
||
('umask 8)
|
||
('mkdir 8)
|
||
('mkstemp 8)
|
||
('logand 16)
|
||
('logior 16)
|
||
('logxor 16)
|
||
('lognot 16))))
|
||
|
||
(define (integer->string integer context)
|
||
"Render INTEGER as a string using a base suitable based on CONTEXT."
|
||
(define (form-base form)
|
||
(match (vhash-assq form %integer-forms)
|
||
(#f 10)
|
||
((_ . base) base)))
|
||
|
||
(define (octal? form)
|
||
(= 8 (form-base form)))
|
||
|
||
(define base
|
||
(match context
|
||
((head . tail)
|
||
(match (form-base head)
|
||
(8 8)
|
||
(16 (if (any octal? tail) 8 16))
|
||
(10 10)))
|
||
(_ 10)))
|
||
|
||
(string-append (match base
|
||
(10 "")
|
||
(16 "#x")
|
||
(8 "#o"))
|
||
(number->string integer base)))
|
||
|
||
(define %special-non-extended-symbols
|
||
;; Special symbols that can be written without the #{...}# notation for
|
||
;; extended symbols: 1+, 1-, 123/, etc.
|
||
(make-regexp "^[0-9]+[[:graph:]]+$" regexp/icase))
|
||
|
||
(define (symbol->display-string symbol context)
|
||
"Return the most appropriate representation of SYMBOL, resorting to extended
|
||
symbol notation only when strictly necessary."
|
||
(let ((str (symbol->string symbol)))
|
||
(if (regexp-exec %special-non-extended-symbols str)
|
||
str ;no need for the #{...}# notation
|
||
(object->string symbol))))
|
||
|
||
(define* (pretty-print-with-comments port obj
|
||
#:key
|
||
(format-comment
|
||
(lambda (comment indent) comment))
|
||
(format-vertical-space identity)
|
||
(indent 0)
|
||
(max-width 78)
|
||
(long-list 5))
|
||
"Pretty-print OBJ to PORT, attempting to at most MAX-WIDTH character columns
|
||
and assuming the current column is INDENT. Comments present in OBJ are
|
||
included in the output.
|
||
|
||
Lists longer than LONG-LIST are written as one element per line. Comments are
|
||
passed through FORMAT-COMMENT before being emitted; a useful value for
|
||
FORMAT-COMMENT is 'canonicalize-comment'. Vertical space is passed through
|
||
FORMAT-VERTICAL-SPACE; a useful value of 'canonicalize-vertical-space'."
|
||
(define (list-of-lists? head tail)
|
||
;; Return true if HEAD and TAIL denote a list of lists--e.g., a list of
|
||
;; 'let' bindings.
|
||
(match head
|
||
((thing _ ...) ;proper list
|
||
(and (not (memq thing
|
||
'(quote quasiquote unquote unquote-splicing)))
|
||
(pair? tail)))
|
||
(_ #f)))
|
||
|
||
(define (starts-with-line-comment? lst)
|
||
;; Return true if LST starts with a line comment.
|
||
(match lst
|
||
((x . _) (and (comment? x) (not (comment-margin? x))))
|
||
(_ #f)))
|
||
|
||
(let loop ((indent indent)
|
||
(column indent)
|
||
(delimited? #t) ;true if comes after a delimiter
|
||
(context '()) ;list of "parent" symbols
|
||
(obj obj))
|
||
(define (print-sequence context indent column lst delimited?)
|
||
(define long?
|
||
(> (length lst) long-list))
|
||
|
||
(let print ((lst lst)
|
||
(first? #t)
|
||
(delimited? delimited?)
|
||
(column column))
|
||
(match lst
|
||
(()
|
||
column)
|
||
((item . tail)
|
||
(define newline?
|
||
;; Insert a newline if ITEM is itself a list, or if TAIL is long,
|
||
;; but only if ITEM is not the first item. Also insert a newline
|
||
;; before a keyword.
|
||
(and (or (pair? item) long?
|
||
(and (keyword? item)
|
||
(not (eq? item #:allow-other-keys))))
|
||
(not first?) (not delimited?)
|
||
(not (blank? item))))
|
||
|
||
(when newline?
|
||
(newline port)
|
||
(display (make-string indent #\space) port))
|
||
(let ((column (if newline? indent column)))
|
||
(print tail
|
||
(keyword? item) ;keep #:key value next to one another
|
||
(blank? item)
|
||
(loop indent column
|
||
(or newline? delimited?)
|
||
context
|
||
item)))))))
|
||
|
||
(define (sequence-would-protrude? indent lst)
|
||
;; Return true if elements of LST written at INDENT would protrude
|
||
;; beyond MAX-WIDTH. This is implemented as a cheap test with false
|
||
;; negatives to avoid actually rendering all of LST.
|
||
(find (match-lambda
|
||
((? string? str)
|
||
(>= (+ (string-width str) 2 indent) max-width))
|
||
((? symbol? symbol)
|
||
(>= (+ (string-width (symbol->display-string symbol context))
|
||
indent)
|
||
max-width))
|
||
((? boolean?)
|
||
(>= (+ 2 indent) max-width))
|
||
(()
|
||
(>= (+ 2 indent) max-width))
|
||
(_ ;don't know
|
||
#f))
|
||
lst))
|
||
|
||
(define (special-form? head)
|
||
(special-form-lead head context))
|
||
|
||
(match obj
|
||
((? comment? comment)
|
||
(if (comment-margin? comment)
|
||
(begin
|
||
(display " " port)
|
||
(display (comment->string (format-comment comment indent))
|
||
port))
|
||
(begin
|
||
;; When already at the beginning of a line, for example because
|
||
;; COMMENT follows a margin comment, no need to emit a newline.
|
||
(unless (= column indent)
|
||
(newline port)
|
||
(display (make-string indent #\space) port))
|
||
(print-multi-line-comment (comment->string
|
||
(format-comment comment indent))
|
||
indent port)))
|
||
(display (make-string indent #\space) port)
|
||
indent)
|
||
((? vertical-space? space)
|
||
(unless delimited? (newline port))
|
||
(let loop ((i (vertical-space-height (format-vertical-space space))))
|
||
(unless (zero? i)
|
||
(newline port)
|
||
(loop (- i 1))))
|
||
(display (make-string indent #\space) port)
|
||
indent)
|
||
((? page-break?)
|
||
(unless delimited? (newline port))
|
||
(display #\page port)
|
||
(newline port)
|
||
(display (make-string indent #\space) port)
|
||
indent)
|
||
(('quote lst)
|
||
(unless delimited? (display " " port))
|
||
(display "'" port)
|
||
(loop indent (+ column (if delimited? 1 2)) #t context lst))
|
||
(('quasiquote lst)
|
||
(unless delimited? (display " " port))
|
||
(display "`" port)
|
||
(loop indent (+ column (if delimited? 1 2)) #t context lst))
|
||
(('unquote lst)
|
||
(unless delimited? (display " " port))
|
||
(display "," port)
|
||
(loop indent (+ column (if delimited? 1 2)) #t context lst))
|
||
(('unquote-splicing lst)
|
||
(unless delimited? (display " " port))
|
||
(display ",@" port)
|
||
(loop indent (+ column (if delimited? 2 3)) #t context lst))
|
||
(('gexp lst)
|
||
(unless delimited? (display " " port))
|
||
(display "#~" port)
|
||
(loop indent (+ column (if delimited? 2 3)) #t context lst))
|
||
(('ungexp obj)
|
||
(unless delimited? (display " " port))
|
||
(display "#$" port)
|
||
(loop indent (+ column (if delimited? 2 3)) #t context obj))
|
||
(('ungexp-native obj)
|
||
(unless delimited? (display " " port))
|
||
(display "#+" port)
|
||
(loop indent (+ column (if delimited? 2 3)) #t context obj))
|
||
(('ungexp-splicing lst)
|
||
(unless delimited? (display " " port))
|
||
(display "#$@" port)
|
||
(loop indent (+ column (if delimited? 3 4)) #t context lst))
|
||
(('ungexp-native-splicing lst)
|
||
(unless delimited? (display " " port))
|
||
(display "#+@" port)
|
||
(loop indent (+ column (if delimited? 3 4)) #t context lst))
|
||
(((? special-form? head) arguments ...)
|
||
;; Special-case 'let', 'lambda', 'modify-inputs', etc. so the second
|
||
;; and following arguments are less indented.
|
||
(let* ((lead (special-form-lead head context))
|
||
(context (cons head context))
|
||
(head (symbol->display-string head (cdr context)))
|
||
(total (length arguments)))
|
||
(unless delimited? (display " " port))
|
||
(display "(" port)
|
||
(display head port)
|
||
(unless (zero? lead)
|
||
(display " " port))
|
||
|
||
;; Print the first LEAD arguments.
|
||
(let* ((indent (+ column 2
|
||
(if delimited? 0 1)))
|
||
(column (+ column 1
|
||
(if (zero? lead) 0 1)
|
||
(if delimited? 0 1)
|
||
(string-length head)))
|
||
(initial-indent column))
|
||
(define new-column
|
||
(let inner ((n lead)
|
||
(arguments (take arguments (min lead total)))
|
||
(column column))
|
||
(if (zero? n)
|
||
(begin
|
||
(newline port)
|
||
(display (make-string indent #\space) port)
|
||
indent)
|
||
(match arguments
|
||
(() column)
|
||
((head . tail)
|
||
(inner (- n 1) tail
|
||
(loop initial-indent column
|
||
(= n lead)
|
||
context
|
||
head)))))))
|
||
|
||
;; Print the remaining arguments.
|
||
(let ((column (print-sequence
|
||
context indent new-column
|
||
(drop arguments (min lead total))
|
||
#t)))
|
||
(display ")" port)
|
||
(+ column 1)))))
|
||
((head tail ...)
|
||
(let* ((overflow? (>= column max-width))
|
||
(column (if overflow?
|
||
(+ indent 1)
|
||
(+ column (if delimited? 1 2))))
|
||
(newline? (or (newline-form? head context)
|
||
(list-of-lists? head tail) ;'let' bindings
|
||
(starts-with-line-comment? tail)))
|
||
(context (cons head context)))
|
||
(if overflow?
|
||
(begin
|
||
(newline port)
|
||
(display (make-string indent #\space) port))
|
||
(unless delimited? (display " " port)))
|
||
(display "(" port)
|
||
|
||
(let* ((new-column (loop column column #t context head))
|
||
(indent (if (or (>= new-column max-width)
|
||
(not (symbol? head))
|
||
(sequence-would-protrude?
|
||
(+ new-column 1) tail)
|
||
newline?)
|
||
column
|
||
(+ new-column 1))))
|
||
(when newline?
|
||
;; Insert a newline right after HEAD.
|
||
(newline port)
|
||
(display (make-string indent #\space) port))
|
||
|
||
(let ((column
|
||
(print-sequence context indent
|
||
(if newline? indent new-column)
|
||
tail newline?)))
|
||
(display ")" port)
|
||
(+ column 1)))))
|
||
(_
|
||
(let* ((str (cond ((string? obj)
|
||
(printed-string obj context))
|
||
((integer? obj)
|
||
(integer->string obj context))
|
||
((symbol? obj)
|
||
(symbol->display-string obj context))
|
||
(else
|
||
(object->string obj))))
|
||
(len (string-width str)))
|
||
(if (and (> (+ column 1 len) max-width)
|
||
(not delimited?))
|
||
(begin
|
||
(newline port)
|
||
(display (make-string indent #\space) port)
|
||
(display str port)
|
||
(+ indent len))
|
||
(begin
|
||
(unless delimited? (display " " port))
|
||
(display str port)
|
||
(+ column (if delimited? 0 1) len))))))))
|
||
|
||
(define (object->string* obj indent . args)
|
||
"Pretty-print OBJ with INDENT columns as the initial indent. ARGS are
|
||
passed as-is to 'pretty-print-with-comments'."
|
||
(call-with-output-string
|
||
(lambda (port)
|
||
(apply pretty-print-with-comments port obj
|
||
#:indent indent
|
||
args))))
|
||
|
||
(define* (pretty-print-with-comments/splice port lst
|
||
#:rest rest)
|
||
"Write to PORT the expressions and blanks listed in LST."
|
||
(for-each (lambda (exp)
|
||
(apply pretty-print-with-comments port exp rest)
|
||
(unless (blank? exp)
|
||
(newline port)))
|
||
lst))
|