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|
;;;; -*- coding: utf-8; mode: scheme -*-
;;;;
;;;; Copyright (C) 2001, 2004, 2006, 2009, 2010,
;;;; 2012, 2013, 2014, 2023 Free Software Foundation, Inc.
;;;;
;;;; 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
;;;;
(define-module (ice-9 pretty-print)
#:use-module (ice-9 match)
#:use-module (srfi srfi-1)
#:use-module (rnrs bytevectors)
#:use-module (ice-9 soft-ports)
#:use-module (ice-9 textual-ports)
#:export (pretty-print
truncated-print))
(define* (call-with-truncating-output-string proc success failure #:key
(initial-column 0)
(max-column 79)
(allow-newline? #f))
(define length 0)
(define strs '())
(define tag (make-prompt-tag))
(define (write-string str)
(set! length (+ length (string-length str)))
(set! strs (cons str strs))
(when (or (< (- max-column initial-column) length)
(and (not allow-newline?)
(not (zero? (port-line port)))))
(abort-to-prompt tag)))
(define port
(make-soft-port #:id "truncating-output-port"
#:write-string write-string))
(call-with-prompt
tag
(lambda ()
(proc port)
(close port)
(success (string-concatenate-reverse strs)))
(lambda (_)
(failure (string-concatenate-reverse strs)))))
;; Parts of pretty-print derived from "genwrite.scm", from SLIB.
;; Copyright (c) 1991, Marc Feeley
;; Author: Marc Feeley (feeley@iro.umontreal.ca)
;; Distribution restrictions: none
(define* (pretty-print obj #:optional port*
#:key
(port (or port* (current-output-port)))
(width 79)
(max-expr-width 50)
(display? #f)
(per-line-prefix ""))
"Pretty-print OBJ on PORT, which is a keyword argument defaulting to
the current output port. Formatting can be controlled by a number of
keyword arguments: Each line in the output is preceded by the string
PER-LINE-PREFIX, which is empty by default. The output lines will be
at most WIDTH characters wide; the default is 79. If DISPLAY? is
true, display rather than write representation will be used.
Instead of with a keyword argument, you can also specify the output
port directly after OBJ, like (pretty-print OBJ PORT)."
(define (wr obj port)
(define (wr-read-macro prefix x)
(put-string port prefix)
(wr x port))
(match obj
(('quote x) (wr-read-macro "'" x))
(('quasiquote x) (wr-read-macro "`" x))
(('unquote x) (wr-read-macro "," x))
(('unquote-splicing x) (wr-read-macro ",@" x))
((head . (rest ...))
;; A proper list: do our own list printing so as to catch read
;; macros that appear in the middle of the list.
(put-string port "(")
(wr head port)
(for-each (lambda (x)
(put-string port " ")
(wr x port))
rest)
(put-string port ")"))
(_
((if display? display write) obj port))))
; define formatting style (change these to suit your style)
(define indent-general 2)
(define max-call-head-width 5)
(define (spaces n)
(when (< 0 n)
(put-string port " " 0 (min 8 n))
(when (< 8 n)
(spaces (- n 8)))))
(define (indent to)
(let ((col (port-column port)))
(cond
((< to col)
(put-string port "\n")
(put-string port per-line-prefix)
(spaces (- to (string-length per-line-prefix))))
(else
(spaces (- to col))))))
(define (pr obj pp-pair)
(match obj
((? vector?)
(put-string port "#")
(pr (vector->list obj) pp-pair))
((not (? pair?))
(wr obj port))
(('quote x) (put-string port "'") (pr x pp-pair))
(('quasiquote x) (put-string port "`") (pr x pp-pair))
(('unquote x) (put-string port ",") (pr x pp-pair))
(('unquote-splicing x) (put-string port ",@") (pr x pp-pair))
(_
;; A pair (and possibly a list). May have to split on multiple
;; lines.
(call-with-truncating-output-string
(lambda (port) (wr obj port))
(lambda (full-str) (put-string port full-str))
(lambda (partial-str) (pp-pair obj))
#:initial-column (port-column port)
#:max-column (- width (string-length per-line-prefix))
#:allow-newline? #f))))
(define (pp-expr expr)
(match expr
(((or 'quote 'quasiquote 'unquote 'unquote-splicing) _)
(pp-quote expr))
(('lambda _ _ . _) (pp-lambda expr))
(('lambda* _ _ . _) (pp-lambda expr))
(('let (? symbol?) _ _ . _) (pp-named-let expr))
(('let _ _ . _) (pp-let expr))
(('let* _ _ . _) (pp-let expr))
(('letrec _ _ . _) (pp-let expr))
(('letrec* _ _ . _) (pp-let expr))
(('let-syntax _ _ . _) (pp-let expr))
(('letrec-syntax _ _ . _) (pp-let expr))
(('define _ _ . _) (pp-define expr))
(('define* _ _ . _) (pp-define expr))
(('define-public _ _ . _) (pp-define expr))
(('define-syntax _ _ . _) (pp-define expr))
(('if _ _ . (or () (_))) (pp-if expr))
(('cond . _) (pp-cond expr))
(('case _ . _) (pp-case expr))
(('begin . _) (pp-begin expr))
(('do _ _ . _) (pp-do expr))
(('syntax-rules _ . _) (pp-syntax-rules expr))
(('syntax-case _ _ . _) (pp-syntax-case expr))
(((? symbol? head) . _)
(if (< max-call-head-width (string-length (symbol->string head)))
(pp-list expr pp-expr)
(pp-call expr pp-expr)))
(_ (pp-list expr pp-expr))))
(define (pp0 head body)
(let ((body-col (+ (port-column port) indent-general)))
(put-string port "(")
(wr head port)
(pp-down body body-col pp-expr)))
(define (pp1 head param0 body pp-param0)
(let ((body-col (+ (port-column port) indent-general)))
(put-string port "(")
(wr head port)
(put-string port " ")
(pr param0 pp-param0)
(pp-down body body-col pp-expr)))
(define (pp2 head param0 param1 body pp-param0 pp-param1)
(let ((body-col (+ (port-column port) indent-general)))
(put-string port "(")
(wr head port)
(put-string port " ")
(pr param0 pp-param0)
(put-string port " ")
(pr param1 pp-param1)
(pp-down body body-col pp-expr)))
(define (pp-quote expr)
(match obj
((head x)
(put-string port
(match x
('quote "'")
('quasiquote "`")
('unquote ",")
('unquote-splicing ",@")))
(pr x pp-expr))))
(define (pp-lambda expr)
(match expr
((head args . body)
(pp1 head args body pp-expr-list))))
(define (pp-let expr)
(match expr
((head bindings . body)
(pp1 head bindings body pp-expr-list))))
(define (pp-named-let expr)
(match expr
((head name bindings . body)
(pp2 head name bindings body pp-expr pp-expr-list))))
(define (pp-define expr)
(match expr
((head args . body)
(pp1 head args body pp-expr-list))))
(define (pp-if expr)
(match expr
((head test . body)
;; "if" indent is 4.
(put-string port "(")
(wr head port)
(put-string port " ")
(let ((body-col (port-column port)))
(pr test pp-expr)
(pp-down body body-col pp-expr)))))
(define (pp-cond expr)
(match expr
((head . clauses)
(pp0 head clauses))))
(define (pp-case expr)
(match expr
((head x . clauses)
(pp1 head x clauses pp-expr))))
(define (pp-begin expr)
(match expr
((head . body) (pp0 head body))))
(define (pp-do expr)
(match expr
((head bindings exit . body)
(pp2 head bindings exit body pp-expr-list pp-expr-list))))
(define (pp-syntax-rules expr)
(match expr
((head literals . clauses)
(pp1 head literals clauses pp-expr-list))))
(define (pp-syntax-case expr)
(match expr
((head stx literals . clauses)
(pp2 head stx literals clauses pp-expr pp-expr-list))))
; (head item1
; item2
; item3)
(define (pp-call expr pp-item)
(match expr
((head . tail)
(put-string port "(")
(wr head port)
(pp-down tail (+ (port-column port) 1) pp-item))))
; (item1
; item2
; item3)
(define (pp-list l pp-item)
(put-string port "(")
(pp-down l (port-column port) pp-item))
(define (pp-down l item-indent pp-item)
(let loop ((l l))
(match l
(() (put-string port ")"))
((head . tail)
(indent item-indent)
(pr head pp-item)
(loop tail))
(improper-tail
(indent item-indent)
(put-string port ".")
(indent item-indent)
(pr improper-tail pp-item)
(put-string port ")")))))
(define (pp-expr-list l)
(pp-list l pp-expr))
(put-string port per-line-prefix)
(pr obj pp-expr)
(newline port)
;; Return `unspecified'
(if #f #f))
(define* (truncated-print x #:optional port*
#:key
(port (or port* (current-output-port)))
(width 79)
(display? #f)
(breadth-first? #f))
"Print @var{x}, truncating the output, if necessary, to make it fit
into @var{width} characters. By default, @var{x} will be printed using
@code{write}, though that behavior can be overriden via the
@var{display?} keyword argument.
The default behavior is to print depth-first, meaning that the entire
remaining width will be available to each sub-expression of @var{x} --
e.g., if @var{x} is a vector, each member of @var{x}. One can attempt to
\"ration\" the available width, trying to allocate it equally to each
sub-expression, via the @var{breadth-first?} keyword argument."
(define ellipsis
;; Choose between `HORIZONTAL ELLIPSIS' (U+2026) and three dots, depending
;; on the encoding of PORT.
(let ((e "…"))
(catch 'encoding-error
(lambda ()
(with-fluids ((%default-port-conversion-strategy 'error))
(call-with-output-string
(lambda (p)
(set-port-encoding! p (port-encoding port))
(display e p)))))
(lambda (key . args)
"..."))))
(let ((ellipsis-width (string-length ellipsis)))
(define* (print-sequence x width len ref next #:key inner?)
(let lp ((x x)
(width width)
(i 0))
(if (> i 0)
(display #\space))
(cond
((= i len)) ; catches 0-length case
((and (= i (1- len)) (or (zero? i) (> width 1)))
(print (ref x i) (if (zero? i) width (1- width)) #:inner? inner?))
((<= width (+ 1 ellipsis-width))
(display ellipsis))
(else
(let ((str (with-output-to-string
(lambda ()
(print (ref x i)
(if breadth-first?
(max 1
(1- (floor (/ width (- len i)))))
(- width (+ 1 ellipsis-width)))
#:inner? inner?)))))
(display str)
(lp (next x) (- width 1 (string-length str)) (1+ i)))))))
(define (print-tree x width)
;; width is >= the width of # . #, which is 5
(let lp ((x x)
(width width))
(cond
((or (not (pair? x)) (<= width 4))
(display ". ")
(print x (- width 2)))
(else
;; width >= 5
(let ((str (with-output-to-string
(lambda ()
(print (car x)
(if breadth-first?
(floor (/ (- width 3) 2))
(- width 4)))))))
(display str)
(display " ")
(lp (cdr x) (- width 1 (string-length str))))))))
(define (truncate-string str width)
(unless (< width (string-length str))
(error "precondition failed"))
(or (or-map (match-lambda
((prefix . suffix)
(and (string-prefix? prefix str)
(<= (+ (string-length prefix)
(string-length suffix)
ellipsis-width)
width)
(format #f "~a~a~a"
(substring str 0
(- width (string-length suffix)
ellipsis-width))
ellipsis
suffix))))
'(("#<" . ">")
("#(" . ")")
("(" . ")")
("\"" . "\"")))
"#"))
(define* (print x width #:key inner?)
(cond
((<= width 0)
(error "expected a positive width" width))
((list? x)
(cond
((>= width (+ 2 ellipsis-width))
(display "(")
(print-sequence x (- width 2) (length x)
(lambda (x i) (car x)) cdr)
(display ")"))
(else
(display "#"))))
((vector? x)
(cond
((>= width (+ 3 ellipsis-width))
(display "#(")
(print-sequence x (- width 3) (vector-length x)
vector-ref identity)
(display ")"))
(else
(display "#"))))
((bytevector? x)
(cond
((>= width 9)
(format #t "#~a(" (array-type x))
(print-sequence x (- width 6) (array-length x)
array-ref identity)
(display ")"))
(else
(display "#"))))
((bitvector? x)
(cond
((>= width (+ 2 (array-length x)))
(format #t "~a" x))
;; the truncated bitvector would print as #1b(...), so we print by hand.
((>= width (+ 2 ellipsis-width))
(format #t "#*")
(array-for-each (lambda (xi) (display (if xi "1" "0")))
(make-shared-array x list (- width 2 ellipsis-width)))
(display ellipsis))
(else
(display "#"))))
((and (array? x) (not (string? x)))
(let* ((type (array-type x))
(prefix
(if inner?
""
(call-with-output-string
(lambda (s) ((@@ (ice-9 arrays) array-print-prefix) x s)))))
(width-prefix (string-length prefix)))
(cond
((>= width (+ 2 width-prefix ellipsis-width))
(format #t "~a(" prefix)
(if (zero? (array-rank x))
(print (array-ref x) (- width width-prefix 2))
(print-sequence x (- width width-prefix 2) (array-length x)
(let ((base (caar (array-shape x))))
(lambda (x i) (array-cell-ref x (+ base i))))
identity
#:inner? (< 1 (array-rank x))))
(display ")"))
(else
(display "#")))))
((pair? x)
(cond
((>= width (+ 4 ellipsis-width))
(display "(")
(print-tree x (- width 2))
(display ")"))
(else
(display "#"))))
(else
(call-with-truncating-output-string
(lambda (port)
(if display? (display x port) (write x port)))
(lambda (full-str)
(display full-str))
(lambda (partial-str)
(display (truncate-string partial-str width)))
#:max-column width
#:allow-newline? #f))))
(with-output-to-port port
(lambda ()
(print x width)))))
|