WIP on typechecking case statements

diff --git a/typecheck.scm b/typecheck.scm
index d180e44e92e755f1e4fbb4172f3535e70f8ebb24..6aca2c1161ab5506189da5fdea2a0675d4761567 100644 (file)
--- a/typecheck.scm
+++ b/typecheck.scm
@@ -244,7 +244,40 @@
                      annotated)))
 
          
-         ('app (check-app env x)))))
+         ('app (check-app env x))
+         ['case
+             (let* ([expr-type-res (check env (case-expr x))]
+                    [expr-type (cadr env)]
+                    [case-match-type-res (map (lambda (x) (check env x))
+                                              (map car (case-cases x)))]
+                    [case-match-types (map cadr case-match-type-res)]
+                    
+                    [case-expr-type-res (map (lambda (x) (check env x))
+                                             (map cadr (case-cases x)))]
+                    [case-expr-types (map cadr case-expr-types-res)]
+
+                    [case-match-equality-cs (fold-left constraint-merge '()
+                                                       (map (lambda (t) (~ t expr-type)) case-match-types))]
+
+                    [case-expr-equality-cs (fold-left constraint-merge '()
+                                                      (map (lambda (t) (~ t (car case-expr-type-res)))
+                                                           (cdr case-expr-type-res)))]
+
+                    [resolved-type (substitute case-expr-eqaulity-cs (car case-expr-type-res))]
+
+                    [annotated `((case (,(case-expr x) : ,expr-type)
+                                   ,(map (lambda (c e et)
+                                           `(,c (,e : ,et)))
+                                         (map car (case-cases x))
+                                         (map cadr (case-cases x))
+                                         case-expr-types)) : ,resolved-type)]
+                    
+                    [cs (fold-left constraint-merge '()
+                                   (append case-match-equality-cs
+                                           case-expr-equality-cs
+                                           (cadr expr-type-res)))])
+               (list cs resolved-type annotated))])))
+               
     ;; (display "result of ")
     ;; (display x)
     ;; (display ":\n\t")