dds/utils.rkt

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#lang typed/racket
(require)
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(provide Symbol VariableMapping
eval-with eval1-with)
(module+ test
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(require typed/rackunit))
;;; ===================
;;; HashTable injection
;;; ===================
(define-type Variable Symbol)
(define-type (VariableMapping A) (Immutable-HashTable Variable A))
(: eval-with (-> (VariableMapping Any) Any AnyValues))
(define (eval-with ht expr)
(parameterize ([current-namespace (make-base-namespace)])
(for ([(x val) (in-hash ht)]) (namespace-set-variable-value! x val))
(eval expr)))
(: eval1-with (-> (VariableMapping Any) Any Any))
(define (eval1-with ht expr)
(call-with-values (λ () (eval-with ht expr))
(λ args (car args))))
(module+ test
(test-case "eval-with"
(check-equal? (eval1-with (hash 'a 1 'b 2) '(+ a b 1))
4)
(define ht : (VariableMapping Integer) (hash 'a 1 'b 2))
(define expr : Any '(+ a b 1))
(check-equal? (eval1-with ht expr)
4)))