blob: 0bb4e56e7be8decabf5d4c7c91b8eff421304675 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
|
;;"genwrite.scm" generic write used by pretty-print and truncated-print.
;; Copyright (c) 1991, Marc Feeley
;; Author: Marc Feeley (feeley@iro.umontreal.ca)
;; Distribution restrictions: none
(define (generic-write obj display? width output)
(define (read-macro? l)
(define (length1? l) (and (pair? l) (null? (cdr l))))
(let ((head (car l)) (tail (cdr l)))
(case head
((QUOTE QUASIQUOTE UNQUOTE UNQUOTE-SPLICING) (length1? tail))
(else #f))))
(define (read-macro-body l)
(cadr l))
(define (read-macro-prefix l)
(let ((head (car l)) (tail (cdr l)))
(case head
((QUOTE) "'")
((QUASIQUOTE) "`")
((UNQUOTE) ",")
((UNQUOTE-SPLICING) ",@"))))
(define (out str col)
(and col (output str) (+ col (string-length str))))
(define (wr obj col)
(define (wr-expr expr col)
(if (read-macro? expr)
(wr (read-macro-body expr) (out (read-macro-prefix expr) col))
(wr-lst expr col)))
(define (wr-lst l col)
(if (pair? l)
(let loop ((l (cdr l))
(col (and col (wr (car l) (out "(" col)))))
(cond ((not col) col)
((pair? l)
(loop (cdr l) (wr (car l) (out " " col))))
((null? l) (out ")" col))
(else (out ")" (wr l (out " . " col))))))
(out "()" col)))
(cond ((pair? obj) (wr-expr obj col))
((null? obj) (wr-lst obj col))
((vector? obj) (wr-lst (vector->list obj) (out "#" col)))
((boolean? obj) (out (if obj "#t" "#f") col))
((number? obj) (out (number->string obj) col))
((symbol? obj) (out (symbol->string obj) col))
((procedure? obj) (out "#[procedure]" col))
((string? obj) (if display?
(out obj col)
(let loop ((i 0) (j 0) (col (out "\"" col)))
(if (and col (< j (string-length obj)))
(let ((c (string-ref obj j)))
(if (or (char=? c #\\)
(char=? c #\"))
(loop j
(+ j 1)
(out "\\"
(out (substring obj i j)
col)))
(loop i (+ j 1) col)))
(out "\""
(out (substring obj i j) col))))))
((char? obj) (if display?
(out (make-string 1 obj) col)
(out (case obj
((#\space) "space")
((#\newline) "newline")
(else (make-string 1 obj)))
(out "#\\" col))))
((input-port? obj) (out "#[input-port]" col))
((output-port? obj) (out "#[output-port]" col))
((eof-object? obj) (out "#[eof-object]" col))
(else (out "#[unknown]" col))))
(define (pp obj col)
(define (spaces n col)
(if (> n 0)
(if (> n 7)
(spaces (- n 8) (out " " col))
(out (substring " " 0 n) col))
col))
(define (indent to col)
(and col
(if (< to col)
(and (out (make-string 1 #\newline) col) (spaces to 0))
(spaces (- to col) col))))
(define (pr obj col extra pp-pair)
(if (or (pair? obj) (vector? obj)) ; may have to split on multiple lines
(let ((result '())
(left (min (+ (- (- width col) extra) 1) max-expr-width)))
(generic-write obj display? #f
(lambda (str)
(set! result (cons str result))
(set! left (- left (string-length str)))
(> left 0)))
(if (> left 0) ; all can be printed on one line
(out (reverse-string-append result) col)
(if (pair? obj)
(pp-pair obj col extra)
(pp-list (vector->list obj) (out "#" col) extra pp-expr))))
(wr obj col)))
(define (pp-expr expr col extra)
(if (read-macro? expr)
(pr (read-macro-body expr)
(out (read-macro-prefix expr) col)
extra
pp-expr)
(let ((head (car expr)))
(if (symbol? head)
(let ((proc (style head)))
(if proc
(proc expr col extra)
(if (> (string-length (symbol->string head))
max-call-head-width)
(pp-general expr col extra #f #f #f pp-expr)
(pp-call expr col extra pp-expr))))
(pp-list expr col extra pp-expr)))))
; (head item1
; item2
; item3)
(define (pp-call expr col extra pp-item)
(let ((col* (wr (car expr) (out "(" col))))
(and col
(pp-down (cdr expr) col* (+ col* 1) extra pp-item))))
; (item1
; item2
; item3)
(define (pp-list l col extra pp-item)
(let ((col (out "(" col)))
(pp-down l col col extra pp-item)))
(define (pp-down l col1 col2 extra pp-item)
(let loop ((l l) (col col1))
(and col
(cond ((pair? l)
(let ((rest (cdr l)))
(let ((extra (if (null? rest) (+ extra 1) 0)))
(loop rest
(pr (car l) (indent col2 col) extra pp-item)))))
((null? l)
(out ")" col))
(else
(out ")"
(pr l
(indent col2 (out "." (indent col2 col)))
(+ extra 1)
pp-item)))))))
(define (pp-general expr col extra named? pp-1 pp-2 pp-3)
(define (tail1 rest col1 col2 col3)
(if (and pp-1 (pair? rest))
(let* ((val1 (car rest))
(rest (cdr rest))
(extra (if (null? rest) (+ extra 1) 0)))
(tail2 rest col1 (pr val1 (indent col3 col2) extra pp-1) col3))
(tail2 rest col1 col2 col3)))
(define (tail2 rest col1 col2 col3)
(if (and pp-2 (pair? rest))
(let* ((val1 (car rest))
(rest (cdr rest))
(extra (if (null? rest) (+ extra 1) 0)))
(tail3 rest col1 (pr val1 (indent col3 col2) extra pp-2)))
(tail3 rest col1 col2)))
(define (tail3 rest col1 col2)
(pp-down rest col2 col1 extra pp-3))
(let* ((head (car expr))
(rest (cdr expr))
(col* (wr head (out "(" col))))
(if (and named? (pair? rest))
(let* ((name (car rest))
(rest (cdr rest))
(col** (wr name (out " " col*))))
(tail1 rest (+ col indent-general) col** (+ col** 1)))
(tail1 rest (+ col indent-general) col* (+ col* 1)))))
(define (pp-expr-list l col extra)
(pp-list l col extra pp-expr))
(define (pp-LAMBDA expr col extra)
(pp-general expr col extra #f pp-expr-list #f pp-expr))
(define (pp-IF expr col extra)
(pp-general expr col extra #f pp-expr #f pp-expr))
(define (pp-COND expr col extra)
(pp-call expr col extra pp-expr-list))
(define (pp-CASE expr col extra)
(pp-general expr col extra #f pp-expr #f pp-expr-list))
(define (pp-AND expr col extra)
(pp-call expr col extra pp-expr))
(define (pp-LET expr col extra)
(let* ((rest (cdr expr))
(named? (and (pair? rest) (symbol? (car rest)))))
(pp-general expr col extra named? pp-expr-list #f pp-expr)))
(define (pp-BEGIN expr col extra)
(pp-general expr col extra #f #f #f pp-expr))
(define (pp-DO expr col extra)
(pp-general expr col extra #f pp-expr-list pp-expr-list pp-expr))
; define formatting style (change these to suit your style)
(define indent-general 2)
(define max-call-head-width 5)
(define max-expr-width 50)
(define (style head)
(case head
((LAMBDA LET* LETREC DEFINE) pp-LAMBDA)
((IF SET!) pp-IF)
((COND) pp-COND)
((CASE) pp-CASE)
((AND OR) pp-AND)
((LET) pp-LET)
((BEGIN) pp-BEGIN)
((DO) pp-DO)
(else #f)))
(pr obj col 0 pp-expr))
(if width
(out (make-string 1 #\newline) (pp obj 0))
(wr obj 0)))
; (reverse-string-append l) = (apply string-append (reverse l))
(define (reverse-string-append l)
(define (rev-string-append l i)
(if (pair? l)
(let* ((str (car l))
(len (string-length str))
(result (rev-string-append (cdr l) (+ i len))))
(let loop ((j 0) (k (- (- (string-length result) i) len)))
(if (< j len)
(begin
(string-set! result k (string-ref str j))
(loop (+ j 1) (+ k 1)))
result)))
(make-string i)))
(rev-string-append l 0))
|
