add $quad-white and `gather-common-attrs`

quad/quad/doc.rkt

@@ -12,8 +12,8 @@
 (define (multiblock . xs) xs)
 
 (define (multiline . xs)
-  (break-lines xs))
+  (wrap-lines xs))
 
-(struct $line (xs) #:transparent)
-(define (break-lines xs)
-  (map (λ(xis) ($line xis)) (slice-at xs 6)))
+(struct $line $quad () #:transparent)
+(define (wrap-lines xs)
+  (map (λ(xis) ($line (gather-common-attrs xis) xis)) (slice-at xs 6)))

quad/quad/parse.rkt

@@ -8,4 +8,4 @@ multicolumn : multiblock [/BLOCK-BREAK multiblock]*
 
 multiblock : multiline [/LINE-BREAK multiline]*
 
-multiline : /WHITESPACE* (QUAD [WHITESPACE+ QUAD]*)* /WHITESPACE* 
+multiline : /QUAD-WHITE* (QUAD [QUAD-WHITE+ QUAD]*)* /QUAD-WHITE* 

quad/quad/quadlang-test.rkt

@@ -1,3 +1,3 @@
 #lang quad/text
 
-Meg is an ally. @(line-break) Meg is an ally.
+Meg is an ally. ;; @(line-break) Meg is an ally.

quad/quad/quads.rkt

@@ -3,6 +3,7 @@
 (require (for-syntax racket/string racket/base racket/syntax))
 
 (struct $quad (attrs list) #:transparent)
+(struct $quad-white $quad () #:transparent)
 
 (define quad? $quad?)
 
@@ -32,6 +33,14 @@ measure (line width)
                #:posn [posn #f])
   (vector size font posn))
 
+(define (gather-common-attrs xs)
+  (define reference-attrs (quad-attrs (car xs)))
+  (for/vector ([idx (in-range (vector-length default-attrs))])
+              (if (for/and ([x (in-list (cdr xs))])
+                           (equal? (vector-ref reference-attrs idx) (vector-ref (quad-attrs x) idx)))
+                  (vector-ref reference-attrs idx)
+                  #f)))
+
 
 (define (attr-size a) (vector-ref a 0))
 (define (attr-font a) (vector-ref a 1))
@@ -41,8 +50,8 @@ measure (line width)
 (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))))
+       (unless (vector-ref dest i)
+         (vector-set! dest i (vector-ref source i))))
   dest)
 
 (require (for-syntax sugar/debug))

quad/quad/tokenize.rkt

@@ -10,7 +10,7 @@
        [(string? x)
         (for/list ([c (in-string x)])
                   (case c
-                    [(#\space #\newline #\return) (token 'WHITESPACE (quad attrs c))]
+                    [(#\space #\newline #\return) (token 'QUAD-WHITE ($quad-white attrs c))]
                     [else (token 'QUAD (quad attrs c))]))]
        [else
         (map (λ(xi) (loop xi ((quad-attrs x) . override-with . attrs))) (quad-list x))]))))