Adding some def transformers

remix/README

@@ -172,7 +172,7 @@ TODO zos don't appear to users (switch to interp if no write access)
 
 TODO only use syntax-parse and define-simple-macro
 
-TODO use \dots as ...
+DONE use \ldots as ...
 
 TODO add a threading macro
 
@@ -205,9 +205,11 @@ 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
+DONE stx def transfomer
 
-TODO mac def transformer (simple-macro)
+TODO fun def transformer
+
+DONE mac def transformer (simple-macro)
 
 TODO mac def+ transformer (syntax-parser)
 

remix/stx0.rkt

@@ -15,7 +15,6 @@
 (define-syntax (def stx)
   (syntax-parse stx
     #:literals (#%brackets)
-    ;; xxx test this
     [(_ (#%brackets dt . _) . _)
      #:declare dt (static def-transformer? "def transformer")
      (def-transform (attribute dt.value) stx)]
@@ -301,6 +300,7 @@
                      binary-operator-precedence)
          #%dot
          (for-syntax gen:dot-transformer)
+         (rename-out [... …])
          #%app
          #%datum
          quote
@@ -311,6 +311,19 @@
          for-syntax
          provide)
 
+(define-syntax val
+  (singleton-struct
+   #:property prop:procedure
+   (λ (stx)
+     (raise-syntax-error 'val "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
+           (define x (remix-block . body)))]))]))
+
 (define-syntax stx
   (singleton-struct
    #:property prop:procedure
@@ -324,4 +337,19 @@
          (syntax/loc stx
            (define-syntax x (remix-block . body)))]))]))
 
-(provide stx)
+(define-syntax mac
+  (singleton-struct
+   #:property prop:procedure
+   (λ (stx)
+     (raise-syntax-error 'mac "Illegal outside def" stx))
+   #:methods gen:def-transformer
+   [(define (def-transform _ stx)
+      (syntax-parse stx
+        #:literals (#%brackets)
+        [(_def (#%brackets _mac (x:id . pat:expr)) . body:expr)
+         (syntax/loc stx
+           (define-simple-macro (x . pat) . body))]))]))
+
+(provide val
+         stx
+         mac)

remix/tests/simple.rkt

@@ -187,5 +187,26 @@
   {(f-rest-args 1) ≡ 42}
   {(f-rest-args 1 2 3) ≡ 42})
 
+;; def supports a variety of "def transformers" that change from
+;; defining a phase-0 value to something else.
+
+;; val ensures that a function is NOT defined
+(def [val v99] 99)
+(module+ test
+  {v99 ≡ 99})
+
+;; stx is define-syntax
 (require (for-syntax remix/stx0))
 (def [stx stx42] 42)
+
+;; mac is define-simple-macro
+(def [mac (flip f x y)]
+  (f y x))
+(module+ test
+  {(flip - 5 0) ≡ (- 0 5)})
+
+;; … (\ldots) is ... (because that doesn't work with cdots)
+(def [mac (flipper f x … y)]
+  (f y x …))
+(module+ test
+  {(flipper - 5 9 0) ≡ (- 0 5 9)})