racket/collects/redex/private/core-layout.rkt
2012-10-31 19:51:50 -05:00

865 lines
33 KiB
Racket

#lang racket/base
(require "loc-wrapper.rkt"
"matcher.rkt"
"reduction-semantics.rkt"
"underscore-allowed.rkt"
texpict/utils
texpict/mrpict
racket/match
racket/draw
racket/class
(for-syntax racket/base))
(define pink-code-font 'modern)
(provide find-enclosing-loc-wrapper
render-lw
lw->pict
basic-text
metafunction-text
grammar-style
paren-style
default-style
label-style
non-terminal-style
non-terminal-subscript-style
non-terminal-superscript-style
label-font-size
default-font-size
metafunction-font-size
non-terminal
literal-style
metafunction-style
delimit-ellipsis-arguments?
open-white-square-bracket
close-white-square-bracket
just-before
just-after
with-unquote-rewriter
with-compound-rewriter
with-compound-rewriters
with-atomic-rewriter
STIX?
white-bracket-sizing
apply-rewrites
;; for test suite
build-lines
(struct-out token)
(struct-out string-token)
(struct-out pict-token)
(struct-out spacer-token)
(struct-out line)
current-text)
(define STIX? #f)
;; atomic-rewrite-table : (parameter (listof (list symbol (union string pict))))
(define atomic-rewrite-table
(make-parameter
`((... ,(λ ()
(if STIX?
(basic-text "\u22ef" (default-style))
(basic-text "..." (default-style)))))
(hole "[]"))))
(define-syntax (with-atomic-rewriter stx)
(syntax-case stx ()
[(_ name transformer e)
#'(parameterize ([atomic-rewrite-table
(cons (list name transformer)
(atomic-rewrite-table))])
e)]))
;; compound-rewrite-table : (listof lw) -> (listof (union lw pict string))
(define compound-rewrite-table
(make-parameter
`((in-hole ,(λ (args)
(let ([context (list-ref args 2)]
[thing-in-hole (list-ref args 3)])
(if (and (lw? thing-in-hole)
(equal? (lw-e thing-in-hole) 'hole))
(list (blank) context (blank))
(list (blank)
context
""
(basic-text "[" (default-style))
thing-in-hole
(basic-text "]" (default-style)))))))
(hide-hole ,(λ (args)
(list (blank)
(list-ref args 2)
(blank))))
(name ,(λ (args)
(let ([open-paren (list-ref args 0)]
[the-name (list-ref args 2)]
[close-paren (list-ref args 4)])
(list (blank)
the-name
(blank))))))))
(define-syntax-rule (with-compound-rewriter name rewriter body)
(with-compound-rewriters ([name rewriter]) body))
(define-syntax with-compound-rewriters
(syntax-rules ()
[(_ ([name rewriter] ...) body)
(parameterize ([compound-rewrite-table
(append (reverse (list (list name rewriter) ...))
(compound-rewrite-table))])
body)]))
(define-syntax (with-unquote-rewriter stx)
(syntax-case stx ()
[(_ transformer e)
#'(parameterize ([current-unquote-rewriter transformer])
e)]))
(define current-unquote-rewriter (make-parameter values))
;; token = string-token | spacer-token | pict-token | align-token | up-token
(define-struct token (column span) #:inspector (make-inspector))
;; string : string
;; style : valid third argument to mrpict.rkt's `text' function
(define-struct (string-token token) (string style) #:inspector (make-inspector))
;; width : number
;; pict : pict
(define-struct (pict-token token) (pict) #:inspector (make-inspector))
;; spacer : number
(define-struct (spacer-token token) () #:inspector (make-inspector))
;; pict : pict
;; this token always appears at the beginning of a line and its width
;; is the x-coordinate of the pict inside itself (which must appear on
;; an earlier line)
(define-struct align-token (pict) #:inspector (make-inspector))
;; lines : number
;; this token corresponds to a deletion of a bunch of vertical space
;; things following it start 'lines' lines higher up.
(define-struct (up-token token) (lines) #:inspector (make-inspector))
;; n : number (the line number)
;; tokens : (listof token)
(define-struct line (n tokens) #:inspector (make-inspector))
(define (render-lw nts lw)
(parameterize ([dc-for-text-size (make-object bitmap-dc% (make-object bitmap% 1 1))])
(lw->pict nts lw)))
(define (lw->pict nts lw)
(lines->pict
(setup-lines
(build-lines
(if (compiled-lang? nts)
(language-nts nts)
nts)
(apply-rewrites lw)))))
(define (apply-rewrites orig-lw)
(define (ar/lw an-lw)
(cond
[(eq? 'spring an-lw) an-lw]
[(lw? an-lw)
(let* ([w-out-term-let (remove-term-let an-lw)]
[rewritten
(if (lw-unq? w-out-term-let)
((current-unquote-rewriter) w-out-term-let)
w-out-term-let)])
(if (equal? rewritten an-lw)
(struct-copy lw
an-lw
[e (ar/e (lw-e an-lw)
(lw-line an-lw)
(lw-line-span an-lw)
(lw-column an-lw)
(lw-column-span an-lw))])
(ar/lw rewritten)))]))
(define (remove-term-let an-lw)
(if (lw-unq? an-lw)
(let ([content (lw-e an-lw)])
(if (and (pair? content)
(pair? (cdr content))
(lw? (cadr content))
(equal? 'term-let (lw-e (cadr content))))
(struct-copy lw
an-lw
[e (append (list (just-before "" an-lw) 'spring)
(lw-e (second-to-last content))
(list 'spring (just-after "" an-lw)))])
an-lw))
an-lw))
(define (ar/e e line line-span col col-span)
(cond
[(symbol? e) e]
[(string? e) e]
[(pict? e) e]
[(and (pair? e)
(lw? (car e))
(member (lw-e (car e)) '("(" "[" "{")) ;; ensures we're really beginning a sequence
;; only useful for typesetting grammars, due to
;; the loc-wrappers that it synthesizes
(pair? (cdr e))
(lw? (cadr e))
(assoc (lw-e (cadr e)) (compound-rewrite-table)))
=>
(λ (m)
(let ([rewritten ((cadr m) e)])
(when (and (pair? rewritten)
(pair? (cdr rewritten))
(eq? (cadr rewritten)
(cadr e)))
(error 'apply-rewrites "rewritten version still has symbol of the same name as original: ~s"
(cadr rewritten)))
(let ([adjusted
(adjust-spacing rewritten
line line-span col col-span
(lw-e (cadr e)))])
(map ar/lw adjusted))))]
[(and (pair? e)
(pair? (cdr e))
(lw? (cadr e))
(lw-metafunction? (cadr e)))
(map ar/lw (rewrite-metafunction-app e
line line-span col col-span
(lw-e (cadr e))))]
[else
(map ar/lw e)]))
(ar/lw orig-lw))
(define (second-to-last l)
(cond
[(null? l) (error 'second-to-last "empty list")]
[(null? (cdr l)) (error 'second-to-last "one element list")]
[else (let loop ([l (cddr l)]
[fst (car l)]
[snd (cadr l)])
(cond
[(null? l) fst]
[else (loop (cdr l)
snd
(car l))]))]))
(define (rewrite-metafunction-app lst line line-span col col-span something-or-other)
(list* (build-lw "" line 0 col 0)
'spring
(just-after (hbl-append
(metafunction-text (symbol->string (lw-e (cadr lst))))
(open-white-square-bracket))
(cadr lst))
'spring
(let loop ([lst (cddr lst)])
(cond
[(null? lst) null]
[(null? (cdr lst))
(let ([last (car lst)])
(list (build-lw "" (lw-line last) 0 (lw-column last) 0)
'spring
(just-after (close-white-square-bracket) last)))]
[(null? (cddr lst))
(cons (car lst) (loop (cdr lst)))]
[else
(if (and (not (delimit-ellipsis-arguments?))
(eq? '... (lw-e (cadr lst))))
(cons (car lst)
(loop (cdr lst)))
(list* (car lst)
(just-after (basic-text "," (default-style)) (car lst))
(loop (cdr lst))))]))))
(define (just-before what lw)
(build-lw (if (symbol? what)
(symbol->string what)
what)
(lw-line lw)
0
(lw-column lw)
0))
(define (just-after what lw)
(build-lw (if (symbol? what)
(symbol->string what)
what)
(+ (lw-line lw) (lw-line-span lw))
0
(+ (lw-column lw) (lw-column-span lw))
0))
;; adjust-spacing : (listof (union string pict loc-wrapper))
;; number
;; number
;; symbol
;; -> (listof loc-wrapper)
;; builds loc-wrappers out of the strings in the rewrittens,
;; using the originals around the string in order to find column numbers for the strings
;; NB: there is still an issue with this code -- if the rewrite drops stuff that
;; appears at the end of the sequence, blank space will still appear in the final output ...
;; When this is fixed, remove the workaround for the `in-hole' rewriter.
(define (adjust-spacing in-rewrittens init-line init-line-span init-column init-column-span who)
(let loop ([rewrittens in-rewrittens]
[line init-line]
[column init-column])
(let* ([to-wrap (collect-non-lws rewrittens)]
[next-lw (first-lws rewrittens)]
[after-next-lw (drop-to-lw-and1 rewrittens)]
[next-lw-line (if next-lw
(lw-line next-lw)
(+ init-line init-line-span))]
[next-lw-column (if next-lw
(lw-column next-lw)
(+ init-column init-column-span))])
;; error checking
(cond
[(= line next-lw-line)
(when (next-lw-column . < . column)
(error 'adjust-spacing "for ~a; loc-wrapper takes up too many columns. Expected it to not pass ~a, but it went to ~a"
who
next-lw-column
column))]
[(next-lw-line . < . line)
(error 'adjust-spacing "for ~a; last loc-wrapper takes up too many lines. Expected it to not pass line ~a, but it went to ~a"
who
next-lw-line
line)])
(let* ([next-line (+ next-lw-line
(if next-lw
(lw-line-span next-lw)
0))]
[next-column (+ next-lw-column
(if next-lw
(lw-column-span next-lw)
0))])
(cond
[(and after-next-lw (null? to-wrap))
(cons next-lw (loop after-next-lw next-line next-column))]
[(and (not after-next-lw) (null? to-wrap))
'()]
[else
(let-values ([(to-wrap1 to-wrap2) (extract-pieces-to-wrap who to-wrap)])
(let ([new-lw-col
(if (= line next-lw-line)
column
init-column)]
[new-lw-col-span
(if (= line next-lw-line)
(- next-lw-column column)
(- next-lw-column init-column))])
(list* (build-lw to-wrap1 line 0 new-lw-col 0)
'spring
(build-lw (blank)
line
(- next-lw-line line)
new-lw-col
new-lw-col-span)
'spring
(build-lw to-wrap2 next-lw-line 0 (+ new-lw-col new-lw-col-span) 0)
(if after-next-lw
(cons next-lw (loop after-next-lw next-line next-column))
'()))))])))))
(define (extract-pieces-to-wrap who lst)
(let ([fst (car lst)])
(if (pair? (cdr lst))
(let ([snd (cadr lst)])
(when (pair? (cddr lst))
(error 'adjust-spacing
"for ~a; found ~a consecutive loc-wrappers, expected at most 2: ~a"
who
(length lst)
(apply string-append
(format "~s" fst)
(map (λ (x) (format " ~s" x)) (cdr lst)))))
(values fst snd))
(values fst (blank)))))
(define (drop-to-lw-and1 lst)
(let loop ([lst lst])
(cond
[(null? lst) #f]
[else
(let ([ele (car lst)])
(if (lw? ele)
(cdr lst)
(loop (cdr lst))))])))
(define (collect-non-lws lst)
(let loop ([lst lst])
(cond
[(null? lst) null]
[else
(let ([ele (car lst)])
(if (lw? ele)
null
(cons ele (loop (cdr lst)))))])))
(define (first-lws lst)
(let loop ([lst lst])
(cond
[(null? lst) #f]
[else
(let ([ele (car lst)])
(if (lw? ele)
ele
(loop (cdr lst))))])))
(define (build-lines all-nts lw)
(define initial-column (lw-column lw))
(define initial-line (lw-line lw))
(define current-line (lw-line lw))
(define current-column (lw-column lw))
;; if there are lines that are in the source,
;; but should not be rendered as blank lines, this counts them
;; specifically it is the number of such lines that have
;; already passed.
(define gobbled-lines 0)
(define last-token-spring? #f)
(define tokens '())
(define lines '())
(define (eject line line-span col col-span atom unquoted?)
(cond
[(= current-line line)
(void)]
[(< current-line line)
(let ([lines-to-end (- line current-line)])
(set! lines (cons (make-line (- current-line gobbled-lines) (reverse tokens)) lines))
(set! tokens '())
(cond [last-token-spring?
;; gobble up empty lines
;; we gobble up lines so that we continue on the line we were
;; on before (which is actually now split into two different elements of the line list)
(set! gobbled-lines (+ gobbled-lines lines-to-end))]
[else
;; insert a bunch of blank lines
(for/list ([i (in-range 1 lines-to-end)])
(define new-line (make-line (+ (- current-line gobbled-lines) i) '()))
(set! lines (cons new-line lines)))])
(set! tokens (cons (make-spacer-token 0 (- col initial-column))
tokens))
(set! current-line line)
(set! current-column col))]
[else
(error 'eject
"lines going backwards (current-line ~s line ~s atom ~s tokens ~s)"
current-line
line
atom
tokens)])
(when (< current-column col)
(let ([space-span (- col current-column)])
(set! tokens (cons (make-blank-space-token unquoted?
(- current-column initial-column)
space-span)
tokens))))
(set! last-token-spring? #f)
(set! tokens (append
(reverse
(atom->tokens (- col initial-column) col-span atom all-nts unquoted?))
tokens))
(set! current-column (+ col col-span)))
(define (make-blank-space-token unquoted? col col-span)
(if last-token-spring?
(make-pict-token col col-span (blank))
(let ([str (apply string (build-list col-span (λ (x) #\space)))])
(if unquoted?
(make-pict-token col col-span (pink-background ((current-text) str pink-code-font (default-font-size))))
(make-string-token col col-span str (default-style))))))
(define (handle-loc-wrapped lw)
(cond
[(memq lw '(spring spring-next))
(set! last-token-spring? lw)]
[else
(handle-object (lw-e lw)
(lw-line lw)
(lw-line-span lw)
(lw-column lw)
(lw-column-span lw)
(lw-unq? lw))]))
(define (handle-object obj line line-span col col-span unquoted?)
(cond
[(symbol? obj) (eject line line-span col col-span obj unquoted?)]
[(string? obj) (eject line line-span col col-span obj unquoted?)]
[(pict? obj) (eject line line-span col col-span obj unquoted?)]
[(not obj) (eject line line-span col col-span (blank) unquoted?)]
[else
(for-each (λ (x) (handle-loc-wrapped x))
obj)]))
(handle-loc-wrapped lw)
(set! lines (cons (make-line (- current-line gobbled-lines) (reverse tokens))
lines)) ;; handle last line ejection
lines)
;; setup-lines : (listof line) -> (listof line)
;; removes the spacer tokens from the beginning of lines, replacing them with align tokens
;; expects the lines to be in reverse order
(define (setup-lines lines)
(let loop ([lines lines])
(cond
[(null? lines) null]
[else
(let* ([line (car lines)]
[line-content (line-tokens line)]
[line-num (line-n line)]
[rst (cdr lines)])
(if (null? line-content)
(cons line (loop (cdr lines)))
(if (spacer-token? (car line-content))
(let ([pict (blank)])
(if (andmap (lambda (x) (null? (line-tokens x))) rst)
(cons (make-line line-num (cdr line-content))
(loop rst))
(let ([rst (split-out (token-span (car line-content))
pict
rst)])
(cons (make-line line-num (cons (make-align-token pict) (cdr line-content)))
(loop rst)))))
(cons line (loop (cdr lines))))))])))
;; split-out : number pict (listof line) -> (listof line)
(define (split-out col pict lines)
(let ([new-token (make-pict-token col 0 pict)])
(let loop ([lines lines])
(cond
[(null? lines)
;; this case can happen when the line in question is to the left of all other lines
(error 'exchange-spacer "could not find matching line")]
[else (let* ([line (car lines)]
[tokens (line-tokens line)])
(if (null? tokens)
(cons line (loop (cdr lines)))
(let ([spacer (car tokens)])
(cond
[(not (spacer-token? spacer))
(cons (make-line (line-n line)
(insert-new-token col new-token (token-column spacer) tokens))
(cdr lines))]
[(= (token-span spacer)
col)
(cons (make-line (line-n line) (list* spacer new-token (cdr tokens)))
(cdr lines))]
[(> (token-span spacer)
col)
(cons line (loop (cdr lines)))]
[(< (token-span spacer)
col)
(cons (make-line (line-n line) (insert-new-token col new-token (token-column spacer) tokens))
(cdr lines))]))))]))))
;; insert-new-token : number token number (listof token) -> (listof token)
(define (insert-new-token column-to-insert new-token init-width tokens)
(let loop ([tokens tokens]
[column 0])
(cond
[(null? tokens)
(list new-token)]
[else
(let ([tok (car tokens)])
(unless (token? tok)
(error 'insert-new-token "ack ~s" tok))
(cond
[(<= column-to-insert (token-column tok))
(cons new-token tokens)]
[(< (token-column tok)
column-to-insert
(+ (token-column tok) (token-span tok)))
(append (split-token (- column-to-insert (token-column tok)) tok new-token)
(cdr tokens))]
[(= column-to-insert (+ (token-column tok) (token-span tok)))
(list* (car tokens) new-token (cdr tokens))]
[else
(cons (car tokens)
(loop (cdr tokens)
(+ (token-column tok) (token-span tok))))]))])))
(define (split-token offset tok new-token)
(cond
[(string-token? tok)
(define len (string-length (string-token-string tok)))
(list (make-string-token (token-column tok)
offset
(substring (string-token-string tok)
0 (min len offset))
(string-token-style tok))
new-token
(make-string-token (+ (token-column tok) offset)
(- (token-span tok) offset)
(substring (string-token-string tok)
(min offset len)
len)
(string-token-style tok)))]
[(pict-token? tok)
(list new-token)]))
;; lines->pict : (non-empty-listof line) -> pict
;; expects the lines to be in order from bottom to top
(define (lines->pict lines)
(let ([lines-ht (make-hash)])
;; this loop builds a pict with all of the lines
;; in order from top to bottom, ignoring the line numbers
;; it also saves the lines in the lines ht above.
;; the lines are first built like that so that 'handle-single-line'
;; can have its 'rst' arguments
(let loop ([lines lines])
(cond
[(null? lines) (blank)]
[(null? (cdr lines))
(let* ([line (car lines)]
[this-pict (handle-single-line line (blank))])
(hash-set! lines-ht
(line-n line)
(cons this-pict (hash-ref lines-ht (line-n line) '())))
this-pict)]
[else
(let ([line (car lines)])
(let* ([rst (loop (cdr lines))]
[this-pict (handle-single-line (car lines) rst)])
(hash-set! lines-ht
(line-n line)
(cons this-pict (hash-ref lines-ht (line-n line) '())))
(vl-append rst this-pict)))]))
;; build the actual pict, based on the line numbers
;; the reverse ensures that when two lines have the same number,
;; the "lower" one is underneat the "upper" one.
(let ([max (apply max (map line-n lines))]
[min (apply min (map line-n lines))])
(let loop ([i min])
(let ([lines (apply lbl-superimpose (reverse (hash-ref lines-ht i (list (blank)))))])
(cond
[(= i max) lines]
[else
(vl-append lines (loop (+ i 1)))]))))))
;; handle-single-line : line pict -> pict
;; builds a line, on the assumption that if the first
;; token in the line is an align-token, then the pict
;; that gives it its width is somewhere in 'rst'.
(define (handle-single-line line rst)
(let ([tokens (line-tokens line)])
(cond
[(null? tokens)
(let ([h (pict-height (token->pict (make-string-token 0 0 "x" (default-style))))])
(blank 0 h))]
[else
(if (align-token? (car tokens))
(let-values ([(x y) (lt-find rst (align-token-pict (car tokens)))])
(apply htl-append
(blank x 0)
(map token->pict (cdr tokens))))
(apply htl-append (map token->pict tokens)))])))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;; font specs
;;
(define (token->pict tok)
(cond
[(string-token? tok)
(basic-text (string-token-string tok) (string-token-style tok))]
[(pict-token? tok) (pict-token-pict tok)]
[else (error 'token->pict "~s" tok)]))
(define (atom->tokens col span atom all-nts unquoted?)
(cond
[(pict? atom)
(list (make-pict-token col span atom))]
[unquoted?
(list (make-pict-token col span
(pink-background
((current-text) (if (string? atom) atom (format "~a" atom))
pink-code-font
(default-font-size)))))]
[(and (symbol? atom)
(regexp-match #rx"^([^_^]*)_([^^]*)\\^?(.*)$" (symbol->string atom)))
=>
(match-lambda
[(list _ nt sub sup)
(let* ([sub-pict (basic-text sub (non-terminal-subscript-style))]
[sup-pict (basic-text sup (non-terminal-superscript-style))]
[sub+sup (lbl-superimpose sub-pict sup-pict)])
(list (non-terminal->token col span nt)
(make-pict-token (+ col span) 0 sub+sup)))])]
[(or (memq atom all-nts)
(memq atom underscore-allowed))
(list (non-terminal->token col span (symbol->string atom)))]
[(symbol? atom)
(list (or (rewrite-atomic col span atom literal-style)
(make-string-token col span (symbol->string atom) (literal-style))))]
[(member atom '("(" ")" "[" "]" "{" "}"))
(list (make-string-token col span atom (paren-style)))]
[(string? atom)
(list (make-string-token col span atom (default-style)))]
[else (error 'atom->tokens "unk ~s" atom)]))
(define (rewrite-atomic col span e get-style)
(cond
[(assoc e (atomic-rewrite-table))
=>
(λ (m)
(when (eq? (cadr m) e)
(error 'apply-rewrites "rewritten version of ~s is still ~s" e e))
(let ([p (cadr m)])
(if (procedure? p)
(make-pict-token col span (p))
(make-string-token col span p (get-style)))))]
[else #f]))
(define (non-terminal->token col span str)
(let ([e (string->symbol str)])
(or (rewrite-atomic col span e non-terminal-style)
(make-string-token col
span
str
(non-terminal-style)))))
(define (pick-font lst fallback)
(let ([fl (get-face-list 'all)])
(let loop ([lst lst])
(cond
[(null? lst) fallback]
[else (if (member (car lst) fl)
(car lst)
(loop (cdr lst)))]))))
(define current-text (make-parameter text))
(define (basic-text str style) ((current-text) str style (default-font-size)))
(define (non-terminal str) ((current-text) str (non-terminal-style) (default-font-size)))
(define (unksc str) (pink-background ((current-text) str pink-code-font (default-font-size))))
(define non-terminal-style (make-parameter '(italic . roman)))
(define non-terminal-subscript-style (make-parameter `(subscript . ,(non-terminal-style))))
(define non-terminal-superscript-style (make-parameter `(superscript . ,(non-terminal-style))))
(define default-style (make-parameter 'roman))
(define grammar-style (make-parameter 'roman))
(define paren-style (make-parameter 'roman))
(define metafunction-style (make-parameter 'swiss))
(define (metafunction-text str) ((current-text) str (metafunction-style) (metafunction-font-size)))
(define literal-style (make-parameter 'swiss))
(define label-style (make-parameter 'swiss))
(define default-font-size (make-parameter 14))
(define metafunction-font-size (make-parameter (default-font-size)))
(define label-font-size (make-parameter 14))
(define delimit-ellipsis-arguments? (make-parameter #t))
(define (open-white-square-bracket) (white-bracket "["))
(define (close-white-square-bracket) (white-bracket "]"))
#;"\u301a\u301b" ;; white square brackets
;; white-bracket : string -> pict
;; puts two of `str' next to each other to make
;; a `white' version of the bracket.
(define (white-bracket str)
(let-values ([(left-inset-amt right-inset-amt left-space right-space)
((white-bracket-sizing) str
(default-font-size))])
(let ([main-bracket (basic-text str (default-style))])
(inset (refocus (cbl-superimpose main-bracket
(hbl-append (blank left-inset-amt)
(basic-text str (default-style))
(blank right-inset-amt)))
main-bracket)
left-space
0
right-space
0))))
(define white-bracket-sizing
(make-parameter
(λ (str size)
(let ([inset-amt (floor/even (max 4 (* size 1/2)))])
(cond
[(equal? str "[")
(values inset-amt
0
0
(/ inset-amt 2))]
[else
(values 0
inset-amt
(/ inset-amt 2)
0)])))))
(define (floor/even x)
(let ([x (floor x)])
(if (odd? x)
(- x 1)
x)))
(define (pink-background p)
(refocus
(cc-superimpose
(colorize (filled-rectangle (pict-width p)
(pict-height p)
#:draw-border? #f)
"pink")
p)
p))
(define (add-between i l)
(cond
[(null? l) l]
[else
(cons (car l)
(apply append
(map (λ (x) (list i x)) (cdr l))))]))
;; for use
(define (find-enclosing-loc-wrapper lws)
(let* ([first-line (apply min (map lw-line lws))]
[last-line (apply min (map (λ (x) (+ (lw-line x) (lw-line-span x))) lws))]
[last-line-lws (find-lws-with-matching-last-line lws last-line)]
[last-column (apply max (map (λ (x) (+ (lw-column x) (lw-column-span x))) last-line-lws))]
[first-column (apply min (map lw-column last-line-lws))])
(build-lw
lws
first-line
(- last-line first-line)
first-column
(- last-column first-column))))
(define (find-lws-with-matching-last-line in-lws line)
(define lws '())
(define (find/lw lw)
(cond
[(eq? lw 'spring) (void)]
[(lw? lw)
(when (= line (+ (lw-line lw) (lw-line-span lw)))
(set! lws (cons lw lws))
(find/e (lw-e lw)))]))
(define (find/e e)
(cond
[(symbol? e) (void)]
[(string? e) (void)]
[(pict? e) (void)]
[else (for-each find/lw e)]))
(find/e in-lws)
lws)