@@ -30,6 +30,11 @@ (define-module (guix read-print)
blank?
+ vertical-space
+ vertical-space?
+ vertical-space-height
+ canonicalize-vertical-space
+
comment
comment?
comment->string
@@ -58,6 +63,26 @@ (define <blank>
(define blank? (record-predicate <blank>))
+(define <vertical-space>
+ (make-record-type '<vertical-space> '(height)
+ #:parent <blank>
+ #:extensible? #f))
+
+(define vertical-space? (record-predicate <vertical-space>))
+(define vertical-space (record-type-constructor <vertical-space>))
+(define vertical-space-height (record-accessor <vertical-space> 'height))
+
+(define (combine-vertical-space x y)
+ "Return vertical space as high as the combination of X and Y."
+ (vertical-space (+ (vertical-space-height x)
+ (vertical-space-height y))))
+
+(define canonicalize-vertical-space
+ (let ((unit (vertical-space 1)))
+ (lambda (space)
+ "Return a vertical space corresponding to a single blank line."
+ unit)))
+
(define <comment>
;; Comments.
(make-record-type '<comment> '(str margin?)
@@ -80,6 +105,19 @@ (define* (comment str #:optional margin?)
(&message (message "invalid comment string")))))
(string->comment str margin?))
+(define (read-vertical-space port)
+ "Read from PORT until a non-vertical-space character is met, and return a
+single <vertical-space> record."
+ (define (space? chr)
+ (char-set-contains? char-set:whitespace chr))
+
+ (let loop ((height 1))
+ (match (read-char port)
+ (#\newline (loop (+ 1 height)))
+ ((? eof-object?) (vertical-space height))
+ ((? space?) (loop height))
+ (chr (unread-char chr port) (vertical-space height)))))
+
(define (read-with-comments port)
"Like 'read', but include <blank> objects when they're encountered."
;; Note: Instead of implementing this functionality in 'read' proper, which
@@ -107,7 +145,9 @@ (define (reverse/dot lst)
eof) ;oops!
(chr
(cond ((eqv? chr #\newline)
- (loop #t return))
+ (if blank-line?
+ (read-vertical-space port)
+ (loop #t return)))
((char-set-contains? char-set:whitespace chr)
(loop blank-line? return))
((memv chr '(#\( #\[))
@@ -297,6 +337,7 @@ (define (canonicalize-comment c)
(define* (pretty-print-with-comments port obj
#:key
(format-comment identity)
+ (format-vertical-space identity)
(indent 0)
(max-width 78)
(long-list 5))
@@ -306,7 +347,8 @@ (define* (pretty-print-with-comments port obj
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'."
+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.
@@ -394,6 +436,14 @@ (define (special-form? head)
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)
(('quote lst)
(unless delimited? (display " " port))
(display "'" port)
@@ -316,7 +316,8 @@ (define* (format-package-definition package
(object->string* exp
(location-column
(package-definition-location package))
- #:format-comment canonicalize-comment)))))
+ #:format-comment canonicalize-comment
+ #:format-vertical-space canonicalize-vertical-space)))))
(define (package-location<? p1 p2)
"Return true if P1's location is \"before\" P2's."
@@ -19,7 +19,8 @@
(define-module (tests-style)
#:use-module (guix read-print)
#:use-module (guix gexp) ;for the reader extensions
- #:use-module (srfi srfi-64))
+ #:use-module (srfi srfi-64)
+ #:use-module (ice-9 match))
(define-syntax-rule (test-pretty-print str args ...)
"Test equality after a round-trip where STR is passed to
@@ -40,6 +41,35 @@ (define-syntax-rule (test-pretty-print str args ...)
(call-with-input-string "(a . b)"
read-with-comments))
+(test-equal "read-with-comments: list with blank line"
+ `(list with ,(vertical-space 1) blank line)
+ (call-with-input-string "\
+(list with
+
+ blank line)\n"
+ read-with-comments))
+
+(test-equal "read-with-comments: list with multiple blank lines"
+ `(list with ,(comment ";multiple\n" #t)
+ ,(vertical-space 3) blank lines)
+ (call-with-input-string "\
+(list with ;multiple
+
+
+
+ blank lines)\n"
+ read-with-comments))
+
+(test-equal "read-with-comments: top-level blank lines"
+ (list (vertical-space 2) '(a b c) (vertical-space 2))
+ (call-with-input-string "
+
+(a b c)\n\n"
+ (lambda (port)
+ (list (read-with-comments port)
+ (read-with-comments port)
+ (read-with-comments port)))))
+
(test-pretty-print "(list 1 2 3 4)")
(test-pretty-print "((a . 1) (b . 2))")
(test-pretty-print "(a b c . boom)")
@@ -181,6 +211,24 @@ (define-syntax-rule (test-pretty-print str args ...)
`(cons \"--without-any-problem\"
,flags)))")
+(test-pretty-print "\
+(vertical-space one:
+
+ two:
+
+
+ three:
+
+
+
+ end)")
+
+(test-pretty-print "\
+(vertical-space one
+
+ ;; Comment after blank line.
+ two)")
+
(test-equal "pretty-print-with-comments, canonicalize-comment"
"\
(list abc
@@ -206,4 +254,30 @@ (define-syntax-rule (test-pretty-print str args ...)
#:format-comment
canonicalize-comment)))))
+(test-equal "pretty-print-with-comments, canonicalize-vertical-space"
+ "\
+(list abc
+
+ def
+
+ ;; last one
+ ghi)"
+ (let ((sexp (call-with-input-string
+ "\
+(list abc
+
+
+
+ def
+
+
+;; last one
+ ghi)"
+ read-with-comments)))
+ (call-with-output-string
+ (lambda (port)
+ (pretty-print-with-comments port sexp
+ #:format-vertical-space
+ canonicalize-vertical-space)))))
+
(test-end)
* guix/read-print.scm (<vertical-space>, vertical-space?) (vertical-space, vertical-space-height): New variables. (combine-vertical-space, canonicalize-vertical-space) (read-vertical-space): New procedures. (read-with-comments): Use it in the #\newline case. (pretty-print-with-comments): Add #:format-vertical-space and honor it. Add case for 'vertical-space?'. * guix/scripts/style.scm (format-package-definition): Pass #:format-vertical-space to 'object->string*'. * tests/read-print.scm ("read-with-comments: list with blank line") ("read-with-comments: list with multiple blank lines") ("read-with-comments: top-level blank lines") ("pretty-print-with-comments, canonicalize-vertical-space"): New tests. Add a couple of additional round-trip tests. --- guix/read-print.scm | 54 ++++++++++++++++++++++++++++-- guix/scripts/style.scm | 3 +- tests/read-print.scm | 76 +++++++++++++++++++++++++++++++++++++++++- 3 files changed, 129 insertions(+), 4 deletions(-)