impc:ti:if-check   scheme

(define impc:ti:if-check
  (lambda (ast vars kts request?)
                                        ;(println 'if: ast 'request? request?)
    (let* ((a (impc:ti:type-check (cadr ast) vars kts #f)) ;request?))
           (b (impc:ti:type-check (caddr ast) vars kts request?))
           (c (if (null? (cdddr ast))
                  '()
                  (impc:ti:type-check (cadddr ast) vars kts request?)))
           (t (impc:ti:type-unify (list b c) vars)))
                                        ;(t (cl:intersection (if (atom? b) (list b) b) (if (atom? c) (list c) c))))
      (if *impc:ti:print-sub-checks* (println 'if:> 'a: a 'b: b 'c: c 't: t))
      ;; (println 'a: a 'b: b 'c: c 't: t)
      (if (null? b)
          (set! t c))
      (if (null? c)
          (set! t b))
      ;; return intersection of b and c
      (if (null? t)
          t ;;(log-error 'Compiler 'Error: 'cannot 'unify 'then b 'and 'else c 'in ast) ;(map (lambda (v) (impc:ir:get-type-str v)) b) 'and 'else (map (lambda (v) (impc:ir:get-type-str v)) c) 'clauses 'in ast)
          t))))