Hi all,
Does anyone know an easy way to add extra indentation to pretty printed
output using racket/pretty?
For example, suppose I want to add pretty printed output after part of
an error message like:
expected: (<pretty printed value>
<should be aligned like this>)
I would want any linebreak-separated portions to align with the first
line with "expected:".
So far, I've tried using the `pretty-print-print-line` parameter to add
some extra indentation, but it doesn't work like I expect. For example:
#lang racket
;; how much extra indentation to add
(define indent 2)
;; to parameterize `pretty-print-print-line`
(define (print-line line-num out old-line-length cols)
(cond [(and line-num
(not (= line-num 0))
(not (eq? cols 'infinity)))
(newline out)
;; these two lines differ from the default
(display (make-string indent #\space) out)
;; changing this to `indent` has weird behavior
0]
[else 0]))
(parameterize ([pretty-print-print-line print-line])
(display " ")
(pretty-display
'(λ (x y z)
(aaaaaaaa bbbbbbbbbbbbbb cccccccccccccc ddddddddd eeeeeeee ffffffff
ggggggg hhhhhhh)))
(newline)
(display " ")
(pretty-display
'(some-other-identifier (x y z)
(aaaaaaaa bbbbbbbbbbbbbb cccccccccccccc ddddddddd eeeeeeee ffffffff
ggggggg hhhhhhh)))
(newline))
The output I'd like to get is (indentation significant):
(lambda (x y z)
(aaaaaaaa
bbbbbbbbbbbbbb
cccccccccccccc
ddddddddd
eeeeeeee
ffffffff
ggggggg
hhhhhhh))
(some-other-identifier
(x y z)
(aaaaaaaa
bbbbbbbbbbbbbb
cccccccccccccc
ddddddddd
eeeeeeee
ffffffff
ggggggg
hhhhhhh))
but I get:
(lambda (x y z)
(aaaaaaaa
bbbbbbbbbbbbbb
cccccccccccccc
ddddddddd
eeeeeeee
ffffffff
ggggggg
hhhhhhh))
(some-other-identifier
(x y z)
(aaaaaaaa
bbbbbbbbbbbbbb
cccccccccccccc
ddddddddd
eeeeeeee
ffffffff
ggggggg
hhhhhhh))
Any idea what I'm doing wrong? There seems to be some extra indentation
added to the output in the inner expression. Am I missing some obvious
easy method to do this?
Cheers,
Asumu
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