Emitting overloaded functions seems to work!

1 files changed, 15 insertions, 9 deletions

diff --git a/chickadee/graphics/seagull.scm b/chickadee/graphics/seagull.scm
index 6b8073d..dcddfb9 100644
--- a/chickadee/graphics/seagull.scm
+++ b/chickadee/graphics/seagull.scm
@@ -1956,6 +1956,17 @@
 ;; of non-quantified function type specifications, one for each unique
 ;; type of call in the program.
 
+;; Check if the substitutions in a and b do not contain
+;; contradictions.
+(define (consistent? a b)
+  (every (match-lambda
+           ((from . to)
+            (let ((other (assq-ref b from)))
+              (or (not other) (equal? to other)))))
+         a))
+
+;; Compute all the valid permutations of substitutions that a
+;; predicate could produce.
 (define (possible-substitutions pred)
   (match pred
     (#t '())
@@ -1974,17 +1985,12 @@
           (append-map (lambda (a)
                         (if (null? rest-options)
                             (list a)
-                            (map (lambda (b)
-                                   (compose-substitutions a b))
-                                 rest-options)))
+                            (filter-map (lambda (b)
+                                          (and (consistent? a b)
+                                               (compose-substitutions a b)))
+                                        rest-options)))
                       options)))))))
 
-(define (possible-signatures type)
-  (define type* (for-all-type-ref type))
-  (map (lambda (subs)
-         (apply-substitutions-to-type type* subs))
-       (possible-substitutions (for-all-type-predicate type))))
-
 (define (resolve-overloads program)
   (match program
     (('t types ('top-level bindings body))