From 874af34a80ab799d0470810b7ade337b96ce50bc Mon Sep 17 00:00:00 2001
From: Eduardo Julian
Date: Tue, 21 Jul 2015 01:03:37 -0400
Subject: - Added a way to pass the cursor from un-expanded macro-forms to
 their expansions in order to aid error-reporting. - Added recursive type
 definitions through the #rec tag in deftype.

---
 input/lux.lux | 105 ++++++++++++++++++++++++++++++++++++++++++++++++----------
 1 file changed, 87 insertions(+), 18 deletions(-)

(limited to 'input/lux.lux')

diff --git a/input/lux.lux b/input/lux.lux
index 0c8b73c34..7ba6cef76 100644
--- a/input/lux.lux
+++ b/input/lux.lux
@@ -295,6 +295,12 @@
 (_lux_export Macro)
 
 ## Base functions & macros
+## (def _cursor
+##   Cursor
+##   ["" -1 -1])
+(_lux_def _cursor
+  (_lux_: Cursor ["" -1 -1]))
+
 ## (def (_meta data)
 ##   (-> (Syntax' (Meta Cursor)) Syntax)
 ##   (#Meta [["" -1 -1] data]))
@@ -303,7 +309,7 @@
                              (#AppT [Meta Cursor])])
                      Syntax])
           (_lux_lambda _ data
-            (#Meta [["" -1 -1] data]))))
+            (#Meta [_cursor data]))))
 
 ## (def (return x)
 ##   (All [a]
@@ -1488,21 +1494,34 @@
     _
     (fail "Wrong syntax for :!")))
 
+(def'' (empty? xs)
+  (All [a] (-> ($' List a) Bool))
+  (_lux_case xs
+    #Nil true
+    _    false))
+
 (defmacro #export (deftype tokens)
   (let [[export? tokens'] (: (, Bool (List Syntax))
-                             (_lux_case (:! (List Syntax) tokens)
+                             (_lux_case tokens
                                (#Cons [(#Meta [_ (#TagS ["" "export"])]) tokens'])
-                               [true (:! (List Syntax) tokens')]
+                               [true tokens']
 
                                _
-                               [false (:! (List Syntax) tokens)]))
-        parts (: (Maybe (, Syntax (List Syntax) Syntax))
+                               [false tokens]))
+        [rec? tokens'] (: (, Bool (List Syntax))
+                          (_lux_case tokens'
+                            (#Cons [(#Meta [_ (#TagS ["" "rec"])]) tokens'])
+                            [true tokens']
+
+                            _
+                            [false tokens']))
+        parts (: (Maybe (, Text (List Syntax) Syntax))
                  (_lux_case tokens'
-                   (#Cons [(#Meta [_ (#SymbolS name)]) (#Cons [type #Nil])])
-                   (#Some [(symbol$ name) #Nil type])
+                   (#Cons [(#Meta [_ (#SymbolS ["" name])]) (#Cons [type #Nil])])
+                   (#Some [name #Nil type])
 
-                   (#Cons [(#Meta [_ (#FormS (#Cons [(#Meta [_ (#SymbolS name)]) args]))]) (#Cons [type #Nil])])
-                   (#Some [(symbol$ name) args type])
+                   (#Cons [(#Meta [_ (#FormS (#Cons [(#Meta [_ (#SymbolS ["" name])]) args]))]) (#Cons [type #Nil])])
+                   (#Some [name args type])
 
                    _
                    #None))]
@@ -1510,21 +1529,71 @@
       (#Some [name args type])
       (let [with-export (: (List Syntax)
                            (if export?
-                             (list (`' (_lux_export (~ name))))
+                             (list (`' (_lux_export (~ (symbol$ ["" name])))))
                              #Nil))
-            type' (: Syntax
-                     (_lux_case args
-                       #Nil
-                       type
+            type' (: (Maybe Syntax)
+                     (if rec?
+                       (if (empty? args)
+                         (let [g!param (symbol$ ["" ""])
+                               prime-name (symbol$ ["" (text:++ name "'")])
+                               type+ (replace-syntax (list [name (`' ((~ prime-name) (~ g!param)))]) type)]
+                           (#Some (`' ((;All (~ prime-name) [(~ g!param)] (~ type+))
+                                       ;Void))))
+                         #None)
+                       (_lux_case args
+                         #Nil
+                         (#Some type)
 
-                       _
-                       (`' (;All (~ name) [(~@ args)] (~ type)))))]
-        (return (list& (`' (_lux_def (~ name) (;type (~ type'))))
-                       with-export)))
+                         _
+                         (#Some (`' (;All (~ (symbol$ ["" name])) [(~@ args)] (~ type)))))))]
+        (_lux_case type'
+          (#Some type'')
+          (return (list& (`' (_lux_def (~ (symbol$ ["" name])) (;type (~ type''))))
+                         with-export))
+
+          #None
+          (fail "Wrong syntax for deftype")))
 
       #None
       (fail "Wrong syntax for deftype"))
     ))
+## (defmacro #export (deftype tokens)
+##   (let [[export? tokens'] (: (, Bool (List Syntax))
+##                              (_lux_case (:! (List Syntax) tokens)
+##                                (#Cons [(#Meta [_ (#TagS ["" "export"])]) tokens'])
+##                                [true (:! (List Syntax) tokens')]
+
+##                                _
+##                                [false (:! (List Syntax) tokens)]))
+##         parts (: (Maybe (, Syntax (List Syntax) Syntax))
+##                  (_lux_case tokens'
+##                    (#Cons [(#Meta [_ (#SymbolS name)]) (#Cons [type #Nil])])
+##                    (#Some [(symbol$ name) #Nil type])
+
+##                    (#Cons [(#Meta [_ (#FormS (#Cons [(#Meta [_ (#SymbolS name)]) args]))]) (#Cons [type #Nil])])
+##                    (#Some [(symbol$ name) args type])
+
+##                    _
+##                    #None))]
+##     (_lux_case parts
+##       (#Some [name args type])
+##       (let [with-export (: (List Syntax)
+##                            (if export?
+##                              (list (`' (_lux_export (~ name))))
+##                              #Nil))
+##             type' (: Syntax
+##                      (_lux_case args
+##                        #Nil
+##                        type
+
+##                        _
+##                        (`' (;All (~ name) [(~@ args)] (~ type)))))]
+##         (return (list& (`' (_lux_def (~ name) (;type (~ type'))))
+##                        with-export)))
+
+##       #None
+##       (fail "Wrong syntax for deftype"))
+##     ))
 
 (defmacro #export (exec tokens)
   (_lux_case (reverse tokens)
-- 
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