From d1233df71b24f843e3c23da8b446226e9b139310 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Sat, 18 Jun 2016 17:21:38 -0700
Subject: [PATCH] get hashy

---
 quad/quad/atomize.rkt | 10 +++++-----
 quad/quad/quads.rkt   | 34 ++++++++++++++++------------------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/quad/quad/atomize.rkt b/quad/quad/atomize.rkt
index 33527f5f..abe2dcd5 100644
--- a/quad/quad/atomize.rkt
+++ b/quad/quad/atomize.rkt
@@ -6,17 +6,17 @@
   (flatten
    (let loop ([x x][loop-attrs default-attrs])
      (cond
-       [(symbol? x) ($shim (attrs #:posn 0) x)]
+       [(symbol? x) ($shim (make-attrs) 0 x)]
        [(string? x)
         (for/list ([c (in-string x)])
-                  (cons ($shim (attrs #:posn 0) 0)
+                  (cons ($shim (make-attrs) 0 0)
                         (case c
-                          [(#\space #\newline #\return) ($white (vector-copy loop-attrs) c)]
-                          [else ($black (vector-copy loop-attrs) c)])))]
+                          [(#\space #\newline #\return) ($white loop-attrs 0 c)]
+                          [else ($black loop-attrs 0 c)])))]
        [else
         (map (λ(xi) (loop xi ((quad-attrs x) . override-with . loop-attrs))) (quad-val x))]))))
 
 (module+ test
   (require rackunit)
-  (atomize (quad (attrs #:size 10 #:font "Eq") "ba" (line-break) "r" (quad (attrs #:size 8) "zam") "q\tux"))
+  (atomize (quad (make-attrs #:size 10 #:font "Eq") "ba" (line-break) "r" (quad (make-attrs #:size 8) "zam") "q\tux"))
   (atomize (quad #f "Meg is " (line-break) "\nan ally.")))
diff --git a/quad/quad/quads.rkt b/quad/quad/quads.rkt
index e7bcd4ff..6cfd8422 100644
--- a/quad/quad/quads.rkt
+++ b/quad/quad/quads.rkt
@@ -2,11 +2,11 @@
 (provide (all-defined-out))
 (require (for-syntax racket/string racket/base racket/syntax))
 
-(struct $quad (attrs val) #:transparent #:mutable)
-(struct $black $quad () #:transparent #:mutable)
-(struct $white $quad () #:transparent #:mutable)
-(struct $skip $quad () #:transparent #:mutable)
-(struct $shim $quad () #:transparent #:mutable)
+(struct $quad (attrs posn val) #:transparent #:mutable)
+(struct $black $quad () #:transparent)
+(struct $white $quad () #:transparent)
+(struct $skip $quad () #:transparent)
+(struct $shim $quad () #:transparent)
 
 (define quad? $quad?)
 
@@ -27,28 +27,26 @@ position
 measure (line width)
 
 |#
-(define default-attrs (vector 12 "Courier" 0))
+(define default-attrs (hasheq 'size 12 'font "Courier"))
 (define (quad attr . xs)
-  ($quad (or attr (attrs)) xs))
+  ($quad (or attr (make-attrs)) 0 xs))
 
-(define (attrs #:size [size #f]
-               #:font [font #f]
-               #:posn [posn #f])
-  (vector size font posn))
+(struct $attrs (size font) #:transparent)
+(define (make-attrs #:size [size #f]
+                    #:font [font #f])
+  (hasheq 'size size 'font font))
 
 
 (define (quad-posn q)
-  (vector-ref ($quad-attrs q) 2))
+  ($quad-posn q))
 
 (define (quad-posn-set! q val)
-  (vector-set! ($quad-attrs q) 2 val))
+  (set-$quad-posn! q val))
 
 (define (override-with dest source)
   ;; replace missing values in dest with values from source
-  (for ([i (in-range (vector-length source))])
-       (unless (vector-ref dest i)
-         (vector-set! dest i (vector-ref source i))))
-  dest)
+  (for/hasheq ([k (in-hash-keys source)])
+              (values k (or (hash-ref dest k) (hash-ref source k)))))
 
 (require (for-syntax sugar/debug))
 (define-syntax (define-break stx)
@@ -68,5 +66,5 @@ measure (line width)
   (define q (quad #f "bar"))
   (check-true (quad? q))
   (check-false (quad? 42))
-  (check-equal? (quad-attrs q) (attrs))
+  (check-equal? (quad-attrs q) (make-attrs))
   (check-equal? (quad-val q) '("bar")))
\ No newline at end of file