[racket users] Pollen tag question

[Kevin Forchione]

Hi guys,
I’ve noticed that the elements being sent to a pollen tag don’t preserve the spacing when the text spans multiple lines for any space occurring before characters on the subsequent line, although does preserve the spacing between characters on that line.Is thes intentional?

For example: Racket 7.8 [cs], latest pollen version:

◊vb{ A B
C D}

Regardless of how many spaces are before the C, the tag elements will only return a single space, although it preserves the spacing between C and D.

Is that the expected result? It seems counter intuitive, as the spacing before A is preserved.

Kevin

[Sorawee Porncharoenwase]

I think the issue is with vb. How does it work?

If you try

#lang pollen

@(define (vb . s) s)

◊vb{     A     B
               C     D}

you will find that it outputs:

'(vb "     A     B"
     "\n" 
     "           " 
     "C     D")

The third element is the space before “C”. It's not discarded.

Also notice that the "start" of the line is at the marker shown below

#lang pollen

@(define (vb . s) s)

◊vb{     A     B
 >>>           C     D}

This is due to how @ syntax works.

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[Sorawee Porncharoenwase]

Whoops. I meant:

#lang pollen 

◊(define (vb . s) s)

◊vb{     A     B
               C     D}

and the output is:

'("     A     B" "\n" "           " "C     D")

[Kevin Forchione]

Here’s my pollen.rkt:

#lang racket/base

(require pollen/decode pollen/misc/tutorial txexpr

         #;(only-in racket make-list string->number))

(provide (all-defined-out))

(define (root . elements)

   (txexpr 'root empty (decode-elements elements

     #:txexpr-elements-proc decode-paragraphs

     #:string-proc (compose1 smart-quotes smart-dashes))))

And  here’s an initial test.html.pm:

#lang pollen

       A       B

       C       D

Which produces

'(root "A       B" (br) "C       D")

Now if I add the vb as you’ve done, but don’t use the tag:

#lang pollen

◊(define (vb . s) s)

       A       B

       C       D

I get this:

'(root "A       B" (br) "       " "C       D")

Kevin

[Kevin Forchione]

If I remove my pollen.rkt from the directory and use:

#lang pollen



A B
C D

I get:
'(root "A B" "\n" "C D”)

But if I use:
#lang pollen
◊(define foo "foo")


A B
C D

I get:
'(root " " "A B" "\n" " " "C D")

Ievin

[Matthew Butterick]

On Oct 29, 2020, at 9:04 PM, Kevin Forchione <lys...@gmail.com> wrote:

I’ve noticed that the elements being sent to a pollen tag don’t preserve the spacing when the text spans multiple lines for any space occurring before characters on the subsequent line, although does preserve the spacing between characters on that line.Is thes intentional?

Yes:

"Spaces at the beginning of body lines do not appear in the resulting S-expressions, but the column of each line is noticed, and all-space indentation strings are added so the result has the same indentation … If the first string came from the opening { line, it is not prepended with an indentation"

https://docs.racket-lang.org/scribble/reader.html?q=spaces%20newlines#%28part._.Spaces__.Newlines__and_.Indentation%29

[Kevin Forchione]

On Oct 30, 2020, at 12:25 PM, Matthew Butterick <m...@mbtype.com> wrote:

Spaces at the beginning of body lines do not appear in the resulting S-expressions, but the column of each line is noticed, and all-space indentation strings are added so the result has the same indentation … If the first string came from the opening { line, it is not prepended with an indentation”

Thanks, Matthew! Understanding dawns. So the padding of lines is relative to the “{“ and not from the beginning of the editor line as I was assuming. How very clever. That makes alignment much easier than I’d thought!  

Is this mentioned anywhere in the pollen tutorials? I must have missed it.

Kevin 

T

[Matthew Butterick]

On Oct 30, 2020, at 1:46 PM, Kevin Forchione <lys...@gmail.com> wrote:

Thanks, Matthew! Understanding dawns. So the padding of lines is relative to the “{“ and not from the beginning of the editor line as I was assuming. How very clever. That makes alignment much easier than I’d thought!  

Is this mentioned anywhere in the pollen tutorials? I must have missed it.

Yes:

"The Pollen language is a variant of Racket’s own text-processing language, called Scribble. Thus, most things that can be done with Scribble syntax can also be done with Pollen syntax. For the sake of clarity & brevity, I’ve only shown you the highlights here. But if you want the full story, see @ Syntax in the Scribble documentation."

https://docs.racket-lang.org/pollen/pollen-command-syntax.html?q=pollen#%28part._.Further_reading%29