From 297a6d5c9224f3ff516795afca62664fbad71e7e Mon Sep 17 00:00:00 2001
From: Jay McCarthy <jay.mccarthy@gmail.com>
Date: Tue, 24 Nov 2015 14:46:47 -0500
Subject: [PATCH] Initial pass at stx def transformer

---
 remix/README           | 10 +++++++++-
 remix/stx0.rkt         | 38 +++++++++++++++++++++++++++++++-------
 remix/tests/simple.rkt |  3 +++
 3 files changed, 43 insertions(+), 8 deletions(-)

diff --git a/remix/README b/remix/README
index 1500455..22c25b3 100644
--- a/remix/README
+++ b/remix/README
@@ -187,7 +187,7 @@ TODO @docs
 DONE [] for Rec def blocks or def* for let* behavior
      and Search for def in block and trans to local-def which sees body
 
-TODO [] for def & def* transformer
+DONE [] for def & def* transformer
 
 TODO Meta def & def* trans for more expansion (docs and test), static
 info (types), and def transformers (types), maybe syntax ---
@@ -204,3 +204,11 @@ https://github.com/greghendershott/def-jambda
 
 DONE nest form like def* for things like parameterize that would look
 weird as def* transformers
+
+TODO stx def transfomer
+
+TODO mac def transformer (simple-macro)
+
+TODO mac def+ transformer (syntax-parser)
+
+TODO parameterize def* transformer
diff --git a/remix/stx0.rkt b/remix/stx0.rkt
index 2939f64..768b787 100644
--- a/remix/stx0.rkt
+++ b/remix/stx0.rkt
@@ -69,11 +69,8 @@
      (syntax/loc stx
        (let () . body))]))
 
-(define-syntax (#%brackets stx)
-  (syntax-parse stx
-    [(_ . body:expr)
-     (syntax/loc stx
-       (remix-block . body))]))
+(define-syntax #%brackets
+  (make-rename-transformer #'remix-block))
 
 (begin-for-syntax
   (define-generics binary-operator
@@ -185,10 +182,17 @@
              #:attr λ-arg (syntax x)
              #:attr λ-bind '())
     ;; xxx write a test for this
-    (pattern (~and def-lhs:expr (#%brackets . _))
+    (pattern (~and def-lhs:expr (#%brackets dt . _))
+             #:declare dt (static def-transformer? "def transformer")
              #:with x (generate-temporary #'def-lhs)
              #:attr λ-arg #'x
-             #:attr λ-bind (list #'(def def-lhs x))))
+             #:attr λ-bind (list #'(def def-lhs x)))
+    ;; xxx write a test for this
+    (pattern (~and def-lhs:expr (#%brackets dt . _))
+             #:declare dt (static def*-transformer? "def* transformer")
+             #:with x (generate-temporary #'def-lhs)
+             #:attr λ-arg #'x
+             #:attr λ-bind (list #'(def* def-lhs x))))
   (define-syntax-class remix-λ-maybe-def-arg
     #:attributes (λ-arg λ-bind)
     (pattern x:remix-λ-raw-arg
@@ -269,6 +273,8 @@
                         (remix-cond . more))))]))
 
 (provide def def*
+         (for-syntax gen:def-transformer
+                     gen:def*-transformer)
          (rename-out [def ≙]
                      [def* ≙*]
                      [def* nest])
@@ -282,6 +288,7 @@
                      binary-operator?
                      binary-operator-precedence)
          #%dot
+         (for-syntax gen:dot-transformer)
          #%app
          #%datum
          quote
@@ -289,4 +296,21 @@
          module
          module*
          module+
+         for-syntax
          provide)
+
+(define-syntax stx
+  (singleton-struct
+   #:property prop:procedure
+   (λ (stx)
+     (raise-syntax-error 'stx "Illegal outside def" stx))
+   #:methods gen:def-transformer
+   [(define (def-transform _ stx)
+      (syntax-parse stx
+        #:literals (#%brackets)
+        [(_def (#%brackets _stx x:id) . body:expr)
+         (syntax/loc stx
+           ;; xxx this "let ()" should be remix-block
+           (define-syntax x (let () . body)))]))]))
+
+(provide stx)
diff --git a/remix/tests/simple.rkt b/remix/tests/simple.rkt
index 6b7a082..7491841 100644
--- a/remix/tests/simple.rkt
+++ b/remix/tests/simple.rkt
@@ -9,6 +9,7 @@
          remix/num/gen0)
 (module+ test
   ;; This introduces ≡ as a testing form
+  ;; XXX Maybe drop this and add a test macro like rackunit/chk
   (require remix/test0))
 
 ;; define is replaced with def
@@ -186,3 +187,5 @@
   {(f-rest-args 1) ≡ 42}
   {(f-rest-args 1 2 3) ≡ 42})
 
+(require (for-syntax remix/stx0))
+(def [stx stx42] 42)