From fd2818b8536c0da6ab9f806071e69448974ecdb9 Mon Sep 17 00:00:00 2001
From: Matthew Butterick <mb@mbtype.com>
Date: Thu, 6 Feb 2020 17:18:29 -0800
Subject: [PATCH] start named quads

---
 quad/quad/quad.rkt         |  4 ++--
 quad/quadwriter/layout.rkt |  1 +
 quad/quadwriter/param.rkt  |  2 ++
 quad/quadwriter/render.rkt | 11 ++++++++++-
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/quad/quad/quad.rkt b/quad/quad/quad.rkt
index 446e9e5f..870889ef 100644
--- a/quad/quad/quad.rkt
+++ b/quad/quad/quad.rkt
@@ -94,9 +94,9 @@
 (define-syntax-rule (quad-copy QID [K V] ...)
   (struct-copy quad QID [K V] ...))
 
-(struct quad-attr (key default-val) #:transparent)
+#;(struct quad-attr (key default-val) #:transparent)
 
-(define (make-quad-attr key [default-val #f])
+#;(define (make-quad-attr key [default-val #f])
   (quad-attr key default-val))
 
 (define (quad-ref q key-arg [default-val-arg #f])
diff --git a/quad/quadwriter/layout.rkt b/quad/quadwriter/layout.rkt
index 7a0520e4..d24e6c89 100644
--- a/quad/quadwriter/layout.rkt
+++ b/quad/quadwriter/layout.rkt
@@ -657,6 +657,7 @@
      #:attrs attrs
      #:from-parent 'sw
      #:to 'nw
+     #:elems (or null (hash-ref (current-named-quads) "foo"))
      #:shift (pt 0 (* 1.5 default-line-height))
      #:printable #true
      #:draw-start (λ (q doc)
diff --git a/quad/quadwriter/param.rkt b/quad/quadwriter/param.rkt
index 97dc973e..fd188bd2 100644
--- a/quad/quadwriter/param.rkt
+++ b/quad/quadwriter/param.rkt
@@ -11,6 +11,7 @@
          (define current-pdf (make-parameter #false))
          (define current-line-wrap (make-parameter #f)) ; because kp is slow and maybe we want to disable for "draft" mode
          (define section-pages-used (make-parameter 0))
+         (define current-named-quads (make-parameter #false))
          
          (define quadwriter-test-mode (make-parameter #f)) ; used during rackunit to suppress nondeterministic elements, like timestamp in header
 
@@ -35,6 +36,7 @@
          (define current-pdf (make-parameter #false))
          (define current-line-wrap (make-parameter #f))
          (define section-pages-used (make-parameter 0))
+         (define current-named-quads (make-parameter #false))
          
          (define quadwriter-test-mode (make-parameter #f))
 
diff --git a/quad/quadwriter/render.rkt b/quad/quadwriter/render.rkt
index eb541ba1..cb5a6e73 100644
--- a/quad/quadwriter/render.rkt
+++ b/quad/quadwriter/render.rkt
@@ -135,6 +135,13 @@
   ;; so if we invoke that style first, we will get a page break.
   (dropf qs break-quad?))
 
+(define (extract-defined-quads qs)
+  (define (get-define-val q) (quad-ref q 'define))
+  (define-values (dqs not-dqs) (partition get-define-val qs))
+  (for ([dq-group (in-list (group-by get-define-val dqs))])
+       (hash-set! (current-named-quads) (get-define-val (car dq-group)) dq-group))
+  not-dqs)
+
 (define default-line-height-multiplier 1.42)
 (define (setup-qs qx-arg base-dir)
   ;; convert our input Q-expression into a useful form.
@@ -164,6 +171,7 @@
          [qs (time-log hyphenate (apply append (map handle-hyphenate qs)))]
          [qs (map generic->typed-quad qs)]
          [qs (drop-leading-breaks qs)]
+         [qs (extract-defined-quads qs)]
          [qs (insert-first-line-indents qs)])
     qs))
 
@@ -388,7 +396,8 @@
                  ;; a lot of operations need to look at pages used so it's easier to
                  ;; make it a parameter than endlessly pass it around as an argument.
                  [section-pages-used 0]
-                 [verbose-quad-printing? #false]) ; for ease of debugging; not mandatory
+                 [verbose-quad-printing? #false]
+                 [current-named-quads (make-hash)]) ; for ease of debugging; not mandatory
     (define qs (time-log setup-qs (setup-qs qx-arg base-dir)))
     (setup-pdf-metadata! qs (current-pdf))
     ;; all the heavy lifting happens inside `make-sections`