Denormalize the type annotated ast, and tag stack values
[scheme.git] / typecheck.scm
index cfb30cc4dc40b690c126d08a5a10fa10688faa62..e3986062e358d763e99746f2ebdd26828337336f 100644 (file)
               scc-env)]
 
         [annotated-bindings (append (cdr acc) ; the previous annotated bindings
-                                    (map cons
+                                    (map list
                                          comps
                                          (map caddr type-results)))])
       (cons new-env annotated-bindings)))
         [let-type (cadr (last body-results))]
         [cs (fold-left (lambda (acc cs) (constraint-merge acc cs)) '() (map car body-results))]
 
-        [annotated `((let ,annotated-bindings ,@(map caddr body-results)))])
+        [annotated `((let ,annotated-bindings ,@(map caddr body-results)) : ,let-type)])
     (list cs let-type annotated)))
 
+(define (check-app env x)
+  (if (eqv? (car x) (cadr x))
+                                       ; recursive function (f f)
+                                       ; TODO: what about ((f a) f)????
+      (let* ([func-type (env-lookup env (car x))]
+            [return-type (fresh-tvar)]
+            [other-func-type `(abs ,func-type ,return-type)]
+            [cs (~ func-type other-func-type)]
+            [resolved-return-type (substitute cs return-type)]
+
+            [annotated `(((,(car x) : ,func-type)
+                          (,(cadr x) : ,func-type)) : ,resolved-return-type)])
+       (list cs resolved-return-type annotated)))
+
+                                       ; regular function
+  (let* ([arg-type-res (check env (cadr x))]
+        [arg-type (cadr arg-type-res)]
+        [func-type-res (check env (car x))]
+        [func-type (cadr func-type-res)]
+        
+                                       ; f ~ a -> t0
+        [func-c (~
+                 (substitute (car arg-type-res) func-type)
+                 `(abs ,arg-type ,(fresh-tvar)))]
+        [cs (constraint-merge
+             (constraint-merge func-c (car arg-type-res))
+             (car func-type-res))]
+        
+        [resolved-func-type (substitute cs func-type)]
+        [resolved-return-type (caddr resolved-func-type)]
+
+        [annotated `((,(caddr func-type-res)
+                      ,(caddr arg-type-res)) : ,resolved-return-type)])
+
+    (if (abs? resolved-func-type)
+       (let ((return-type (substitute cs (caddr resolved-func-type))))
+         (list cs return-type annotated))
+       (error #f "not a function"))))
 
 ; returns a list (constraints type annotated)
 (define (check env x)
 
                     [lambda-type `(abs ,resolved-arg-type ,(cadr body-type-res))]
 
-                    ; TODO: do we need to annotate the lambda argument?
-                    [annotated `(lambda (,(lambda-arg x)) ,(caddr body-type-res))])
+                    [annotated `((lambda (,(lambda-arg x)) ,(caddr body-type-res)) : ,lambda-type)])
                
                (list (car body-type-res) ; constraints
                      lambda-type  ; type
                      annotated)))
 
          
-         ('app ; (f a)
-          (if (eqv? (car x) (cadr x))
-                                       ; recursive function (f f)
-              (let* ([func-type (env-lookup env (car x))]
-                     [return-type (fresh-tvar)]
-                     [other-func-type `(abs ,func-type ,return-type)]
-                     [cs (~ func-type other-func-type)]
-                     [resolved-return-type (substitute cs return-type)]
-
-                     [annotated `(((,(car x) : ,func-type)
-                                   (,(cadr x) : ,func-type)) : ,resolved-return-type)])
-                (list cs resolved-return-type annotated)))
-
-                                       ; regular function
-          (let* ([arg-type-res (check env (cadr x))]
-                 [arg-type (cadr arg-type-res)]
-                 [func-type-res (check env (car x))]
-                 [func-type (cadr func-type-res)]
-                 
-                                       ; f ~ a -> t0
-                 [func-c (~
-                          (substitute (car arg-type-res) func-type)
-                          `(abs ,arg-type ,(fresh-tvar)))]
-                 [cs (constraint-merge
-                      (constraint-merge func-c (car arg-type-res))
-                      (car func-type-res))]
-                 
-                 [resolved-func-type (substitute cs func-type)]
-                 [resolved-return-type (caddr resolved-func-type)]
-
-                 [annotated `((,(caddr func-type-res)
-                               ,(caddr arg-type-res)) : ,resolved-return-type)])
-
-            (if (abs? resolved-func-type)
-                (let ((return-type (substitute cs (caddr resolved-func-type))))
-                  (list cs return-type annotated))
-                (error #f "not a function")))))))
+         ('app (check-app env x)))))
     ;; (display "result of ")
     ;; (display x)
     ;; (display ":\n\t")
     res))
 
 (define (init-adts-env prog)
-  (flat-map data-tors-env (map data-layout (program-datas prog))))
+  (flat-map data-tors-env (program-data-layouts prog)))
 
                                        ; we typecheck the lambda calculus only (only single arg lambdas)
 (define (typecheck prog)
   (cadr (check (init-adts-env prog) (normalize (program-body prog)))))
 
+
+                                       ; before passing annotated types onto codegen
+                                       ; we need to restore the pre-normalization structure
+                                       ; (this is important for function arity etc)
+(define (denormalize orig normed)
+
+  (define (collapse-lambdas n x)
+    (case n
+      [0 x]
+      [else
+       (let* ([inner-lambda (lambda-body (ann-expr x))]
+             [arg (lambda-arg (ann-expr x))]
+             [inner-collapsed (ann-expr (collapse-lambdas (- n 1) inner-lambda))])
+        `((lambda ,(cons arg (lambda-args inner-collapsed))
+            ,(lambda-body inner-collapsed)) : ,(ann-type x)))]))
+
+  (define (collapse-apps n x)
+    (case n
+      [-1 (error #f "nullary functions not handled yet")]
+      [0 x]
+      [else
+       (let* ([inner-app (car (ann-expr x))]
+             [inner-collapsed (collapse-apps (- n 1) inner-app)])
+        `(,(append (ann-expr inner-collapsed) (cdr (ann-expr x))) : ,(ann-type x)))]))
+
+  (case (ast-type orig)
+    ['lambda
+       (let ([collapsed (collapse-lambdas (- (length (lambda-args orig)) 1) normed)])
+         `((lambda ,(lambda-args (ann-expr collapsed))
+             ,(denormalize (lambda-body orig)
+                           (lambda-body (ann-expr collapsed)))) : ,(ann-type collapsed)))]
+    ['app
+     (let ([collapsed (collapse-apps (- (length orig) 2) normed)])
+       `(,(map (lambda (o n) (denormalize o n)) orig (ann-expr collapsed))
+        : ,(ann-type collapsed)))]
+    ['let
+       `((let ,(map (lambda (o n) (list (car o) (denormalize (cadr o) (cadr n))))
+                    (let-bindings orig)
+                    (let-bindings (ann-expr normed)))
+           ,@(map (lambda (o n) (denormalize o n))
+                  (let-body orig)
+                  (let-body (ann-expr normed)))) : ,(ann-type normed))]
+    ['if `((if ,@(map denormalize (cdr orig) (cdr (ann-expr normed))))
+          : (ann-type normed))]
+    [else normed]))
+
+(define ann-expr car)
+(define ann-type caddr)
 (define (annotate-types prog)
-  (caddr (check (init-adts-env prog) (normalize (program-body prog)))))
+  (denormalize (program-body prog)
+  (caddr (check (init-adts-env prog) (normalize (program-body prog))))))
 
   
                                        ; returns a list of constraints