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c5e05a1c | 1 | ;;;; -*- coding: utf-8; mode: scheme -*- |
a482f2cc | 2 | ;;;; |
c5e05a1c | 3 | ;;;; Copyright (C) 2001, 2004, 2006, 2009, 2010 Free Software Foundation, Inc. |
a482f2cc | 4 | ;;;; |
73be1d9e MV |
5 | ;;;; This library is free software; you can redistribute it and/or |
6 | ;;;; modify it under the terms of the GNU Lesser General Public | |
7 | ;;;; License as published by the Free Software Foundation; either | |
53befeb7 | 8 | ;;;; version 3 of the License, or (at your option) any later version. |
a482f2cc | 9 | ;;;; |
73be1d9e | 10 | ;;;; This library is distributed in the hope that it will be useful, |
a482f2cc | 11 | ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
73be1d9e MV |
12 | ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | ;;;; Lesser General Public License for more details. | |
a482f2cc | 14 | ;;;; |
73be1d9e MV |
15 | ;;;; You should have received a copy of the GNU Lesser General Public |
16 | ;;;; License along with this library; if not, write to the Free Software | |
92205699 | 17 | ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
a482f2cc | 18 | ;;;; |
1a179b03 | 19 | (define-module (ice-9 pretty-print) |
8c6eea2f AW |
20 | #:export (pretty-print |
21 | truncated-print)) | |
c1ff4aa7 | 22 | |
b337528f MV |
23 | |
24 | ;; From SLIB. | |
25 | ||
26 | ;;"genwrite.scm" generic write used by pretty-print and truncated-print. | |
27 | ;; Copyright (c) 1991, Marc Feeley | |
28 | ;; Author: Marc Feeley (feeley@iro.umontreal.ca) | |
29 | ;; Distribution restrictions: none | |
30 | ||
31 | (define genwrite:newline-str (make-string 1 #\newline)) | |
32 | ||
f5259dd3 | 33 | (define (generic-write obj display? width per-line-prefix output) |
b337528f MV |
34 | |
35 | (define (read-macro? l) | |
36 | (define (length1? l) (and (pair? l) (null? (cdr l)))) | |
37 | (let ((head (car l)) (tail (cdr l))) | |
38 | (case head | |
39 | ((quote quasiquote unquote unquote-splicing) (length1? tail)) | |
40 | (else #f)))) | |
41 | ||
42 | (define (read-macro-body l) | |
43 | (cadr l)) | |
44 | ||
45 | (define (read-macro-prefix l) | |
5bc8bc69 | 46 | (let ((head (car l))) |
b337528f MV |
47 | (case head |
48 | ((quote) "'") | |
49 | ((quasiquote) "`") | |
50 | ((unquote) ",") | |
51 | ((unquote-splicing) ",@")))) | |
52 | ||
53 | (define (out str col) | |
54 | (and col (output str) (+ col (string-length str)))) | |
55 | ||
56 | (define (wr obj col) | |
2d51a8a1 MV |
57 | (cond ((and (pair? obj) |
58 | (read-macro? obj)) | |
59 | (wr (read-macro-body obj) | |
60 | (out (read-macro-prefix obj) col))) | |
61 | (else | |
62 | (out (object->string obj (if display? display write)) col)))) | |
b337528f MV |
63 | |
64 | (define (pp obj col) | |
65 | ||
66 | (define (spaces n col) | |
67 | (if (> n 0) | |
68 | (if (> n 7) | |
69 | (spaces (- n 8) (out " " col)) | |
70 | (out (substring " " 0 n) col)) | |
71 | col)) | |
72 | ||
73 | (define (indent to col) | |
74 | (and col | |
75 | (if (< to col) | |
f5259dd3 MV |
76 | (and (out genwrite:newline-str col) |
77 | (out per-line-prefix 0) | |
78 | (spaces to 0)) | |
b337528f MV |
79 | (spaces (- to col) col)))) |
80 | ||
81 | (define (pr obj col extra pp-pair) | |
82 | (if (or (pair? obj) (vector? obj)) ; may have to split on multiple lines | |
83 | (let ((result '()) | |
84 | (left (min (+ (- (- width col) extra) 1) max-expr-width))) | |
f5259dd3 | 85 | (generic-write obj display? #f "" |
b337528f MV |
86 | (lambda (str) |
87 | (set! result (cons str result)) | |
88 | (set! left (- left (string-length str))) | |
89 | (> left 0))) | |
90 | (if (> left 0) ; all can be printed on one line | |
91 | (out (reverse-string-append result) col) | |
92 | (if (pair? obj) | |
93 | (pp-pair obj col extra) | |
94 | (pp-list (vector->list obj) (out "#" col) extra pp-expr)))) | |
95 | (wr obj col))) | |
96 | ||
97 | (define (pp-expr expr col extra) | |
98 | (if (read-macro? expr) | |
99 | (pr (read-macro-body expr) | |
100 | (out (read-macro-prefix expr) col) | |
101 | extra | |
102 | pp-expr) | |
103 | (let ((head (car expr))) | |
104 | (if (symbol? head) | |
105 | (let ((proc (style head))) | |
106 | (if proc | |
107 | (proc expr col extra) | |
108 | (if (> (string-length (symbol->string head)) | |
109 | max-call-head-width) | |
110 | (pp-general expr col extra #f #f #f pp-expr) | |
111 | (pp-call expr col extra pp-expr)))) | |
112 | (pp-list expr col extra pp-expr))))) | |
113 | ||
114 | ; (head item1 | |
115 | ; item2 | |
116 | ; item3) | |
117 | (define (pp-call expr col extra pp-item) | |
118 | (let ((col* (wr (car expr) (out "(" col)))) | |
119 | (and col | |
120 | (pp-down (cdr expr) col* (+ col* 1) extra pp-item)))) | |
121 | ||
122 | ; (item1 | |
123 | ; item2 | |
124 | ; item3) | |
125 | (define (pp-list l col extra pp-item) | |
126 | (let ((col (out "(" col))) | |
127 | (pp-down l col col extra pp-item))) | |
128 | ||
129 | (define (pp-down l col1 col2 extra pp-item) | |
130 | (let loop ((l l) (col col1)) | |
131 | (and col | |
132 | (cond ((pair? l) | |
133 | (let ((rest (cdr l))) | |
134 | (let ((extra (if (null? rest) (+ extra 1) 0))) | |
135 | (loop rest | |
136 | (pr (car l) (indent col2 col) extra pp-item))))) | |
137 | ((null? l) | |
138 | (out ")" col)) | |
139 | (else | |
140 | (out ")" | |
141 | (pr l | |
142 | (indent col2 (out "." (indent col2 col))) | |
143 | (+ extra 1) | |
144 | pp-item))))))) | |
145 | ||
146 | (define (pp-general expr col extra named? pp-1 pp-2 pp-3) | |
147 | ||
148 | (define (tail1 rest col1 col2 col3) | |
149 | (if (and pp-1 (pair? rest)) | |
150 | (let* ((val1 (car rest)) | |
151 | (rest (cdr rest)) | |
152 | (extra (if (null? rest) (+ extra 1) 0))) | |
153 | (tail2 rest col1 (pr val1 (indent col3 col2) extra pp-1) col3)) | |
154 | (tail2 rest col1 col2 col3))) | |
155 | ||
156 | (define (tail2 rest col1 col2 col3) | |
157 | (if (and pp-2 (pair? rest)) | |
158 | (let* ((val1 (car rest)) | |
159 | (rest (cdr rest)) | |
160 | (extra (if (null? rest) (+ extra 1) 0))) | |
161 | (tail3 rest col1 (pr val1 (indent col3 col2) extra pp-2))) | |
162 | (tail3 rest col1 col2))) | |
163 | ||
164 | (define (tail3 rest col1 col2) | |
165 | (pp-down rest col2 col1 extra pp-3)) | |
166 | ||
167 | (let* ((head (car expr)) | |
168 | (rest (cdr expr)) | |
169 | (col* (wr head (out "(" col)))) | |
170 | (if (and named? (pair? rest)) | |
171 | (let* ((name (car rest)) | |
172 | (rest (cdr rest)) | |
173 | (col** (wr name (out " " col*)))) | |
174 | (tail1 rest (+ col indent-general) col** (+ col** 1))) | |
175 | (tail1 rest (+ col indent-general) col* (+ col* 1))))) | |
176 | ||
177 | (define (pp-expr-list l col extra) | |
178 | (pp-list l col extra pp-expr)) | |
179 | ||
180 | (define (pp-LAMBDA expr col extra) | |
181 | (pp-general expr col extra #f pp-expr-list #f pp-expr)) | |
182 | ||
183 | (define (pp-IF expr col extra) | |
184 | (pp-general expr col extra #f pp-expr #f pp-expr)) | |
185 | ||
186 | (define (pp-COND expr col extra) | |
187 | (pp-call expr col extra pp-expr-list)) | |
188 | ||
189 | (define (pp-CASE expr col extra) | |
190 | (pp-general expr col extra #f pp-expr #f pp-expr-list)) | |
191 | ||
192 | (define (pp-AND expr col extra) | |
193 | (pp-call expr col extra pp-expr)) | |
194 | ||
195 | (define (pp-LET expr col extra) | |
196 | (let* ((rest (cdr expr)) | |
197 | (named? (and (pair? rest) (symbol? (car rest))))) | |
198 | (pp-general expr col extra named? pp-expr-list #f pp-expr))) | |
199 | ||
200 | (define (pp-BEGIN expr col extra) | |
201 | (pp-general expr col extra #f #f #f pp-expr)) | |
202 | ||
203 | (define (pp-DO expr col extra) | |
204 | (pp-general expr col extra #f pp-expr-list pp-expr-list pp-expr)) | |
205 | ||
206 | ; define formatting style (change these to suit your style) | |
207 | ||
208 | (define indent-general 2) | |
209 | ||
210 | (define max-call-head-width 5) | |
211 | ||
212 | (define max-expr-width 50) | |
213 | ||
214 | (define (style head) | |
215 | (case head | |
216 | ((lambda let* letrec define) pp-LAMBDA) | |
217 | ((if set!) pp-IF) | |
218 | ((cond) pp-COND) | |
219 | ((case) pp-CASE) | |
220 | ((and or) pp-AND) | |
221 | ((let) pp-LET) | |
222 | ((begin) pp-BEGIN) | |
223 | ((do) pp-DO) | |
224 | (else #f))) | |
225 | ||
226 | (pr obj col 0 pp-expr)) | |
227 | ||
f5259dd3 | 228 | (out per-line-prefix 0) |
b337528f MV |
229 | (if width |
230 | (out genwrite:newline-str (pp obj 0)) | |
21a10205 MV |
231 | (wr obj 0)) |
232 | ;; Return `unspecified' | |
233 | (if #f #f)) | |
b337528f MV |
234 | |
235 | ; (reverse-string-append l) = (apply string-append (reverse l)) | |
236 | ||
237 | (define (reverse-string-append l) | |
238 | ||
239 | (define (rev-string-append l i) | |
240 | (if (pair? l) | |
241 | (let* ((str (car l)) | |
242 | (len (string-length str)) | |
243 | (result (rev-string-append (cdr l) (+ i len)))) | |
244 | (let loop ((j 0) (k (- (- (string-length result) i) len))) | |
245 | (if (< j len) | |
246 | (begin | |
247 | (string-set! result k (string-ref str j)) | |
248 | (loop (+ j 1) (+ k 1))) | |
249 | result))) | |
250 | (make-string i))) | |
251 | ||
252 | (rev-string-append l 0)) | |
253 | ||
8c6eea2f | 254 | (define* (pretty-print obj #:optional port* |
c1ff4aa7 | 255 | #:key |
8c6eea2f | 256 | (port (or port* (current-output-port))) |
c1ff4aa7 AW |
257 | (width 79) |
258 | (display? #f) | |
259 | (per-line-prefix "")) | |
f5259dd3 MV |
260 | "Pretty-print OBJ on PORT, which is a keyword argument defaulting to |
261 | the current output port. Formatting can be controlled by a number of | |
262 | keyword arguments: Each line in the output is preceded by the string | |
263 | PER-LINE-PREFIX, which is empty by default. The output lines will be | |
264 | at most WIDTH characters wide; the default is 79. If DISPLAY? is | |
265 | true, display rather than write representation will be used. | |
266 | ||
267 | Instead of with a keyword argument, you can also specify the output | |
268 | port directly after OBJ, like (pretty-print OBJ PORT)." | |
f5259dd3 MV |
269 | (generic-write obj display? |
270 | (- width (string-length per-line-prefix)) | |
271 | per-line-prefix | |
8c6eea2f AW |
272 | (lambda (s) (display s port) #t))) |
273 | ||
c5e05a1c | 274 | \f |
8c6eea2f AW |
275 | ;; `truncated-print' was written in 2009 by Andy Wingo, and is not from |
276 | ;; genwrite.scm. | |
277 | (define* (truncated-print x #:optional port* | |
278 | #:key | |
279 | (port (or port* (current-output-port))) | |
280 | (width 79) | |
281 | (display? #f) | |
282 | (breadth-first? #f)) | |
283 | "Print @var{obj}, truncating the output, if necessary, to make it fit | |
284 | into @var{width} characters. By default, @var{x} will be printed using | |
285 | @code{write}, though that behavior can be overriden via the | |
286 | @var{display?} keyword argument. | |
287 | ||
288 | The default behaviour is to print depth-first, meaning that the entire | |
c5e05a1c | 289 | remaining width will be available to each sub-expression of @var{x} -- |
8c6eea2f AW |
290 | e.g., if @var{x} is a vector, each member of @var{x}. One can attempt to |
291 | \"ration\" the available width, trying to allocate it equally to each | |
292 | sub-expression, via the @var{breadth-first?} keyword argument." | |
293 | ||
c5e05a1c LC |
294 | ;; Make sure string ports are created with the right encoding. |
295 | (with-fluids ((%default-port-encoding (port-encoding port))) | |
296 | ||
297 | (define ellipsis | |
298 | ;; Choose between `HORIZONTAL ELLIPSIS' (U+2026) and three dots, depending | |
299 | ;; on the encoding of PORT. | |
300 | (let ((e "…")) | |
301 | (catch 'encoding-error | |
302 | (lambda () | |
303 | (with-output-to-string | |
304 | (lambda () | |
305 | (display e)))) | |
306 | (lambda (key . args) | |
307 | "...")))) | |
308 | ||
309 | (let ((ellipsis-width (string-length ellipsis))) | |
310 | ||
311 | (define (print-sequence x width len ref next) | |
312 | (let lp ((x x) | |
313 | (width width) | |
314 | (i 0)) | |
315 | (if (> i 0) | |
316 | (display #\space)) | |
317 | (cond | |
318 | ((= i len)) ; catches 0-length case | |
319 | ((= i (1- len)) | |
320 | (print (ref x i) (if (zero? i) width (1- width)))) | |
321 | ((<= width (+ 1 ellipsis-width)) | |
322 | (display "...")) | |
323 | (else | |
324 | (let ((str | |
325 | (with-fluids ((%default-port-encoding (port-encoding port))) | |
326 | (with-output-to-string | |
327 | (lambda () | |
328 | (print (ref x i) | |
329 | (if breadth-first? | |
330 | (max 1 | |
331 | (1- (floor (/ width (- len i))))) | |
332 | (- width (+ 1 ellipsis-width))))))))) | |
333 | (display str) | |
334 | (lp (next x) (- width 1 (string-length str)) (1+ i))))))) | |
335 | ||
336 | (define (print-tree x width) | |
337 | ;; width is >= the width of # . #, which is 5 | |
338 | (let lp ((x x) | |
339 | (width width)) | |
340 | (cond | |
341 | ((or (not (pair? x)) (<= width 4)) | |
342 | (display ". ") | |
343 | (print x (- width 2))) | |
344 | (else | |
345 | ;; width >= 5 | |
346 | (let ((str (with-output-to-string | |
347 | (lambda () | |
348 | (print (car x) | |
349 | (if breadth-first? | |
350 | (floor (/ (- width 3) 2)) | |
351 | (- width 4))))))) | |
352 | (display str) | |
353 | (display " ") | |
354 | (lp (cdr x) (- width 1 (string-length str)))))))) | |
355 | ||
356 | (define (truncate-string str width) | |
357 | ;; width is < (string-length str) | |
358 | (let lp ((fixes '(("#<" . ">") | |
359 | ("#(" . ")") | |
360 | ("(" . ")") | |
361 | ("\"" . "\"")))) | |
362 | (cond | |
363 | ((null? fixes) | |
364 | "#") | |
365 | ((and (string-prefix? (caar fixes) str) | |
366 | (string-suffix? (cdar fixes) str) | |
367 | (>= (string-length str) | |
368 | width | |
369 | (+ (string-length (caar fixes)) | |
370 | (string-length (cdar fixes)) | |
371 | ellipsis-width))) | |
372 | (format #f "~a~a~a~a" | |
373 | (caar fixes) | |
374 | (substring str (string-length (caar fixes)) | |
375 | (- width (string-length (cdar fixes)) | |
376 | ellipsis-width)) | |
377 | ellipsis | |
378 | (cdar fixes))) | |
379 | (else | |
380 | (lp (cdr fixes)))))) | |
381 | ||
382 | (define (print x width) | |
383 | (cond | |
384 | ((<= width 0) | |
385 | (error "expected a positive width" width)) | |
386 | ((list? x) | |
387 | (cond | |
388 | ((>= width (+ 2 ellipsis-width)) | |
389 | (display "(") | |
390 | (print-sequence x (- width 2) (length x) | |
391 | (lambda (x i) (car x)) cdr) | |
392 | (display ")")) | |
393 | (else | |
394 | (display "#")))) | |
395 | ((vector? x) | |
396 | (cond | |
397 | ((>= width (+ 3 ellipsis-width)) | |
398 | (display "#(") | |
399 | (print-sequence x (- width 3) (vector-length x) | |
400 | vector-ref identity) | |
401 | (display ")")) | |
402 | (else | |
403 | (display "#")))) | |
404 | ((uniform-vector? x) | |
405 | (cond | |
406 | ((>= width 9) | |
407 | (format #t "#~a(" (uniform-vector-element-type x)) | |
408 | (print-sequence x (- width 6) (uniform-vector-length x) | |
409 | uniform-vector-ref identity) | |
410 | (display ")")) | |
411 | (else | |
412 | (display "#")))) | |
413 | ((pair? x) | |
414 | (cond | |
415 | ((>= width (+ 4 ellipsis-width)) | |
416 | (display "(") | |
417 | (print-tree x (- width 2)) | |
418 | (display ")")) | |
419 | (else | |
420 | (display "#")))) | |
421 | (else | |
422 | (let* ((str (with-output-to-string | |
423 | (lambda () (if display? (display x) (write x))))) | |
424 | (len (string-length str))) | |
425 | (display (if (<= (string-length str) width) | |
426 | str | |
427 | (truncate-string str width))))))) | |
428 | ||
429 | (with-output-to-port port | |
430 | (lambda () | |
431 | (print x width)))))) |