delete font-size-previous key

quad2/constants.rkt

@@ -17,5 +17,4 @@
   [:font-path (make-attr-path-key 'font-path)]
   [:font-bold (make-attr-boolean-key 'font-bold #true #false)]
   [:font-italic (make-attr-boolean-key 'font-italic #true #false)]
-  [:font-size (make-attr-dimension-string-key 'font-size #true default-font-size)]
+  [:font-size (make-attr-dimension-string-key 'font-size #true default-font-size)])
-  [:font-size-previous (make-attr-dimension-string-key 'font-size-previous)])

quad2/font.rkt

@@ -160,25 +160,20 @@
   #:post (list-of quad?)
   
   (define (resolve-font-size-once attrs parent-attrs)
+    (define previous-font-size
+      (cond
+        [(and parent-attrs (hash-ref parent-attrs :font-size #false))]
+        [else default-font-size]))
     (define base-size-adjusted
-      (match (hash-ref attrs :font-size 'missing)
+      (match (hash-ref attrs :font-size #false)
+        [(? procedure? proc)
          ;; if our value represents an adjustment,
          ;; we apply the adjustment to the previous value
-        [(? procedure? proc)
-         (define previous-font-size (cond
-                                      [(and parent-attrs (hash-ref parent-attrs :font-size-previous #false))]
-                                      [else default-font-size]))
          (proc previous-font-size)]
         ;; otherwise we use our value directly
         [(? number? num) num]
-        [other (raise-user-error 'resolve-font-sizes "procedure or number" other)]))
+        [other #false]))
-    ;; we write our new value into both font-size and font-size-previous
+    (hash-set! attrs :font-size (or base-size-adjusted previous-font-size)))
-    ;; because as we cascade down, we're likely to come across superseding values
-    ;; of font-size
-    ;; but the font-size-previous will persist
-    ;; because on the next recursion, the current `attrs` will be `parent-attrs`
-    (hash-set*! attrs :font-size base-size-adjusted
-                :font-size-previous base-size-adjusted))
 
   (for-each-attrs qs resolve-font-size-once))
 

quad2/main.rkt

@@ -21,7 +21,12 @@
                   ;; all attrs start out as symbol-string pairs.
                   ;; we convert keys & values to corresponding higher-level types.
                   upgrade-attr-keys
-                  fill-default-attr-values
+                  ;; I think this is wrong. Filling in default values here
+                  ;; will prevent parent values from cascading during linearization
+                  ;; but it would be OK at the top level, to ensure
+                  ;; that there are values that cascade
+                  ;; but that can be done by wrapping in a quad with the default values
+                  #;fill-default-attr-values
                   downcase-string-attr-values
                   convert-boolean-attr-values
                   convert-numeric-attr-values
@@ -30,6 +35,7 @@
                   ;; these need the tree shape
                   parse-dimension-strings
                   resolve-font-sizes
+                  #;resolve-font-features
 
                   ;; linearization =============
                   ;; we postpone this step until we're certain any