From 1e82bd68e9018b2066eed0910ca9aa3001f678a8 Mon Sep 17 00:00:00 2001
From: Jay McCarthy <jay.mccarthy@gmail.com>
Date: Mon, 30 Nov 2015 14:31:09 -0500
Subject: [PATCH] Expansion examples, fixing raw def usage, adding planner type

---
 remix/data0.rkt             | 47 +++++++++++++++++++++++++++++++------
 remix/tests/expand-from.rkt |  6 +++++
 remix/tests/expand-to.rkt   | 16 +++++++++++++
 remix/tests/simple.rkt      |  6 ++++-
 4 files changed, 67 insertions(+), 8 deletions(-)
 create mode 100644 remix/tests/expand-from.rkt
 create mode 100644 remix/tests/expand-to.rkt

diff --git a/remix/data0.rkt b/remix/data0.rkt
index e71c4b3..b7b91cd 100644
--- a/remix/data0.rkt
+++ b/remix/data0.rkt
@@ -11,6 +11,7 @@
           (for-syntax racket/base
                       racket/syntax
                       syntax/parse
+                      racket/generic
                       (prefix-in remix: remix/stx0)))
          racket/unsafe/ops
          racket/performance-hint
@@ -90,10 +91,6 @@
                  (quasisyntax/loc stx
                    (remix:def (remix:#%brackets x-def #,x-stx) x-def-v))))
              (singleton-struct
-              ;; XXX some way to overload this with #:extensions
-              #:property prop:procedure
-              (λ (_ stx)
-                (raise-syntax-error 'int-name "Illegal in expression context" stx))
               #:methods gen:static-interface
               [(define (static-interface-members _)
                  available-ids)]
@@ -140,7 +137,22 @@
                           (remix:def (remix:#%brackets remix:stx i)
                                      (phase1:static-interface
                                       (remix:#%brackets lhs def-rhs)
-                                      ...)))))]))]
+                                      ...
+                                      #:extensions
+                                      ;; NB I don't pass on other
+                                      ;; extensions... I don't think
+                                      ;; it can possibly make sense,
+                                      ;; because I don't know what
+                                      ;; they might be.
+                                      #:property prop:procedure
+                                      (λ (_ stx)
+                                       (syntax-parse stx
+                                         [_:id
+                                          (syntax/loc stx
+                                            real-i)]
+                                         [(_ . blah:expr)
+                                          (syntax/loc stx
+                                            (real-i . blah))])))))))]))]
               extension ...))))])))
 
 (define-syntax (define-phase0-def->phase1-macro stx)
@@ -173,7 +185,18 @@
 
 (begin-for-syntax
   ;; XXX fill this in for parents, etc
-  (define-generics layout))
+  (define-generics layout)
+  (begin-for-syntax
+    (define-generics layout-planner
+      (layout-planner-mutable? layout-planner)))
+  (define-syntax layout-immutable
+    (singleton-struct
+     #:methods gen:layout-planner
+     [(define (layout-planner-mutable? lp) #f)]))
+  (define-syntax layout-mutable
+    (singleton-struct
+     #:methods gen:layout-planner
+     [(define (layout-planner-mutable? lp) #t)])))
 
 (define-syntax phase0:layout
   (singleton-struct
@@ -276,5 +299,15 @@
                   [])))))]))]))
 
 (provide (rename-out [phase0:layout layout])
+         (for-meta 2
+                   gen:layout-planner
+                   layout-planner?
+                   layout-planner-mutable?)
          (for-syntax gen:layout
-                     layout?))
+                     layout?
+                     layout-immutable
+                     layout-mutable))
+
+;; xxx (dynamic-)interface
+;; xxx data
+
diff --git a/remix/tests/expand-from.rkt b/remix/tests/expand-from.rkt
new file mode 100644
index 0000000..992d072
--- /dev/null
+++ b/remix/tests/expand-from.rkt
@@ -0,0 +1,6 @@
+#lang remix
+(require remix/stx0
+         remix/data0)
+(def [layout posn]
+  x y)
+(provide posn)
diff --git a/remix/tests/expand-to.rkt b/remix/tests/expand-to.rkt
new file mode 100644
index 0000000..2e0b16a
--- /dev/null
+++ b/remix/tests/expand-to.rkt
@@ -0,0 +1,16 @@
+#lang remix
+(require remix/stx0
+         remix/num/gen0
+         "expand-from.rkt")
+
+(def [posn p1] (posn.#:alloc [x 5] [y 7]))
+p1.x
+p1.y
+
+(def [posn p2] (p1.#:set [y {p1.y + 2}]))
+p2.x
+p2.y
+
+(def [posn p3] (p1.#:= [x 8]))
+p3.x
+p3.y
diff --git a/remix/tests/simple.rkt b/remix/tests/simple.rkt
index 77709ca..75d6918 100644
--- a/remix/tests/simple.rkt
+++ b/remix/tests/simple.rkt
@@ -331,6 +331,10 @@
   ;; And accessors
   {p1.x ≡ 5}
   {p1.y ≡ 7}
+  ;; You may not have noticed, but posn was just a def transformer
+  ;; that gave us access to these. We can, of course, just call them
+  ;; directly through posn.
+  {(posn.x p1) ≡ 5}
   ;; You will also get a copying function (XXX: Should it be named
   ;; `copy`? `update`? My analogy here is with hash-set)
   (def [posn p2] (p1.#:set [y {p1.y + 2}]))
@@ -361,7 +365,7 @@
 ;; as a rule.)
 #;
 (def [layout circle]
-  [posn cx] r)
+  [posn c] r)
 
 ;; A layout's fields can _actually_ just be any def transformer, and
 ;; thus could be static interfaces