You cannot select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
typesetting/quad/quad2/compile.rkt

115 lines
4.3 KiB
Racket

#lang debug racket/base
(require racket/contract
racket/function
rackunit
racket/list
racket/match
racket/string
racket/format
"pass.rkt"
"drawing.rkt"
"quad.rkt")
(provide quad-compile quad-compile-to-stack stackify valid-tokens)
(define/contract (posn-add p0 p1)
($point? $size? . -> . $point?)
($point (+ ($point-x p0) ($size-width p1)) (+ ($point-y p0) ($size-height p1))))
(define/contract (size char)
(quad? . -> . $size?)
($size 1 1))
(define/contract (advance char)
(quad? . -> . $size?)
($size 1 0))
(define/contract (quadify str)
(string? . -> . (listof quad?))
(for/list ([c (in-string str)])
(make-quad #f (list (cons 'char c)))))
(define (make-compiler . passes)
(apply compose1 (reverse (cons quadify passes))))
(define (min-x rect) ($point-x ($rect-origin rect)))
(define (width rect) ($size-width ($rect-size rect)))
(define (max-x rect) (+ (min-x rect) (width rect)))
(define (min-y rect) ($point-y ($rect-origin rect)))
(define (height rect) ($size-height ($rect-size rect)))
(define (max-y rect) (+ (min-y rect) (height rect)))
(define/contract (rect-contains-point? rect pt)
($rect? $point? . -> . boolean?)
(and (<= (min-x rect) ($point-x pt) (max-x rect))
(<= (min-y rect) ($point-y pt) (max-y rect))))
(define/contract (rect-contains-rect? outer inner)
($rect? $rect? . -> . boolean?)
(and (rect-contains-point? outer ($rect-origin inner))
(rect-contains-point? outer ($point (max-x inner) (max-y inner)))))
(define (has-position? q) (not (eq? (quad-posn q) #false)))
(define-pass (layout qs)
#:precondition (λ (qs) (and (list? qs) (andmap (λ (q) (not (has-position? q))) qs)))
#:postcondition (λ (qs) (and (list? qs) (andmap has-position? qs)))
(define frame ($rect ($point 0 0) ($size (current-wrap-width) 30)))
(define (quad-fits? q posn)
(define q-size (size q))
(define quad-rect ($rect posn q-size))
(and (rect-contains-rect? frame quad-rect) posn))
(for/fold ([posn ($point 0 0)]
#:result qs)
([q (in-list qs)])
(define first-posn-on-next-line ($point 0 (add1 ($point-y posn))))
(define winning-posn (or (ormap (λ (posn) (quad-fits? q posn)) (list posn first-posn-on-next-line)) (error 'no-posn-that-fits)))
(set-quad-posn! q winning-posn)
(posn-add winning-posn (advance q))))
(define-pass (make-drawing-insts qs)
#:precondition (λ (qs) (and (list? qs) (andmap has-position? qs)))
#:postcondition (λ (qs) (and (list? qs) (andmap $drawing-inst? qs)))
(flatten
(list ($doc 'start) ($page 'start)
(for/list ([q (in-list qs)])
(cond
[(quad? q)
(list ($move (quad-posn q)) ($text (char->integer (quad-char q))))]
[else (error 'render-unknown-thing)]))
($page 'end) ($doc 'end))))
(define valid-tokens '(doc-start doc-end page-start page-end text move))
(define-pass (stackify xs)
#:precondition (λ (xs) (and (list? xs) (andmap $drawing-inst? xs)))
#:postcondition string?
(define move-points (map $move-posn (filter $move? xs)))
(define xmax (add1 (apply max (map $point-x move-points))))
(define ymax (add1 (apply max (map $point-y move-points))))
(string-join
(for/list ([x (in-list xs)])
(string-join (map ~a (match x
[($move ($point x y)) (list y x 'move)]
[($text charint) (list charint 'text)]
[($doc 'start) '(doc-start)]
[($doc 'end) '(doc-end)]
[($page 'start) (list ymax xmax 'page-start)]
[($page 'end) '(page-end)]
[_ (error 'unknown-drawing-inst)])) " ")) "\n"))
(define quad-compile-to-stack (make-compiler layout make-drawing-insts stackify))
(define quad-compile (make-compiler layout make-drawing-insts))
#;(check-equal?
(list
($quad ($point 0 0) #\H)
($quad ($point 1 0) #\e)
($quad ($point 2 0) #\l)
($quad ($point 3 0) #\l)
($quad ($point 4 0) #\o)
($quad ($point 0 1) #\space)
($quad ($point 1 1) #\w)
($quad ($point 2 1) #\o)
($quad ($point 3 1) #\r)
($quad ($point 4 1) #\l)
($quad ($point 0 2) #\d)))