add stlc+box

tapl/stlc+box.rkt

@@ -0,0 +1,38 @@
+#lang racket/base
+(require
+  (for-syntax racket/base syntax/parse syntax/stx racket/syntax racket/string
+              "stx-utils.rkt" "typecheck.rkt")
+  (for-meta 2 racket/base syntax/parse racket/syntax)
+  "typecheck.rkt")
+(require (prefix-in stlc: (only-in "stlc+cons.rkt" #%app λ))
+         (except-in "stlc+cons.rkt" #%app λ))
+(provide (rename-out [stlc:#%app #%app] [stlc:λ λ]))
+(provide (all-from-out "stlc+cons.rkt"))
+(provide ref deref :=)
+
+;; Simply-Typed Lambda Calculus, plus mutable references
+;; Types:
+;; - types from stlc+cons.rkt
+;; - Ref constructor
+;; Terms:
+;; - terms from stlc+cons.rkt
+
+(define-type-constructor Ref)
+
+(define-syntax (ref stx)
+  (syntax-parse stx
+    [(_ e)
+     #:with (e- τ) (infer+erase #'e)
+     (⊢ #'(box e-) #'(Ref τ))]))
+(define-syntax (deref stx)
+  (syntax-parse stx
+    [(_ e)
+     #:with (e- ((~literal Ref) τ)) (infer+erase #'e)
+     (⊢ #'(unbox e-) #'τ)]))
+(define-syntax (:= stx)
+  (syntax-parse stx
+    [(_ e_ref e)
+     #:with (e_ref- ((~literal Ref) τ1)) (infer+erase #'e_ref)
+     #:with (e- τ2) (infer+erase #'e)
+     #:when (τ= #'τ1 #'τ2)
+     (⊢ #'(set-box! e_ref- e-) #'Unit)]))

tapl/stlc+cons.rkt

@@ -14,9 +14,10 @@
 ;; Simply-Typed Lambda Calculus, plus cons
 ;; Types:
 ;; - types from stlc+var.rkt
+;; - List constructor
 ;; Terms:
 ;; - terms from stlc+var.rkt
-;; - define constants only
+;; - define, constants only
 
 ;; TODO: enable HO use of list primitives
 

tapl/tests/stlc+box.rkt

@@ -0,0 +1,214 @@
+#lang s-exp "../stlc+box.rkt"
+(require "rackunit-typechecking.rkt")
+
+(define x (ref 10))
+(check-type x : (Ref Int))
+(check-type (deref x) : Int ⇒ 10)
+(check-type (:= x 20) : Unit) ; x still 10 because check-type does not evaluate
+(check-type (begin (:= x 20) (deref x)) : Int ⇒ 20)
+(check-type x : (Ref Int))
+(check-type (deref (ref 20)) : Int ⇒ 20)
+(check-type (deref x) : Int ⇒ 20)
+
+(check-type ((λ ([b : (Ref Int)]) (deref b)) (ref 10)) : Int ⇒ 10)
+(check-type ((λ ([b : (Ref Int)]) (begin (begin (:= b 20) (deref b)))) (ref 10)) : Int ⇒ 20)
+
+;; previous tests: ------------------------------------------------------------
+(typecheck-fail (cons 1 2))
+(typecheck-fail (cons 1 nil))
+(check-type (cons 1 (nil {Int})) : (List Int))
+(typecheck-fail nil)
+(typecheck-fail (nil Int))
+(typecheck-fail (nil (Int)))
+; passes bc ⇒-rhs is only used for its runtime value
+(check-type (nil {Int}) : (List Int) ⇒ (nil {Bool}))
+(check-not-type (nil {Bool}) : (List Int))
+(check-type (nil {Bool}) : (List Bool))
+(check-type (nil {(→ Int Int)}) : (List (→ Int Int)))
+(define fn-lst (cons (λ ([x : Int]) (+ 10 x)) (nil {(→ Int Int)})))
+(check-type fn-lst : (List (→ Int Int)))
+(check-type (isnil fn-lst) : Bool ⇒ #f)
+(typecheck-fail (isnil (head fn-lst))) ; head lst is not List
+(check-type (isnil (tail fn-lst)) : Bool ⇒ #t)
+(check-type (head fn-lst) : (→ Int Int))
+(check-type ((head fn-lst) 25) : Int ⇒ 35)
+(check-type (tail fn-lst) : (List (→ Int Int)) ⇒ (nil {(→ Int Int)}))
+
+;; previous tests: ------------------------------------------------------------
+;; define-type-alias
+(define-type-alias Integer Int)
+(define-type-alias ArithBinOp (→ Int Int Int))
+
+(check-type ((λ ([x : Int]) (+ x 2)) 3) : Integer)
+(check-type ((λ ([x : Integer]) (+ x 2)) 3) : Int)
+(check-type ((λ ([x : Integer]) (+ x 2)) 3) : Integer)
+(check-type + : ArithBinOp)
+(check-type (λ ([f : ArithBinOp]) (f 1 2)) : (→ (→ Int Int Int) Int))
+
+;; records (ie labeled tuples)
+(check-type "Stephen" : String)
+(check-type (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) :
+            (× ["name" String] ["phone" Int] ["male?" Bool]))
+(check-type (proj (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) "name")
+            : String ⇒ "Stephen")
+(check-type (proj (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) "name")
+            : String ⇒ "Stephen")
+(check-type (proj (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) "phone")
+            : Int ⇒ 781)
+(check-type (proj (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) "male?")
+            : Bool ⇒ #t)
+(check-not-type (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) :
+                (× ["my-name" String] ["phone" Int] ["male?" Bool]))
+(check-not-type (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) :
+                (× ["name" String] ["my-phone" Int] ["male?" Bool]))
+(check-not-type (tup ["name" = "Stephen"] ["phone" = 781] ["male?" = #t]) :
+                (× ["name" String] ["phone" Int] ["is-male?" Bool]))
+
+
+(check-type (var "coffee" = (void) as (∨ ["coffee" Unit])) : (∨ ["coffee" Unit]))
+(check-not-type (var "coffee" = (void) as (∨ ["coffee" Unit])) : (∨ ["coffee" Unit] ["tea" Unit]))
+(typecheck-fail ((λ ([x : (∨ ["coffee" Unit] ["tea" Unit])]) x)
+                 (var "coffee" = (void) as (∨ ["coffee" Unit]))))
+(check-type (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit])) : (∨ ["coffee" Unit] ["tea" Unit]))
+(check-type (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit] ["coke" Unit]))
+            : (∨ ["coffee" Unit] ["tea" Unit] ["coke" Unit]))
+
+(typecheck-fail
+ (case (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit]))
+   ["coffee" x => 1])) ; not enough clauses
+(typecheck-fail
+ (case (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit]))
+   ["coffee" x => 1]
+   ["teaaaaaa" x => 2])) ; wrong clause
+(typecheck-fail
+ (case (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit]))
+   ["coffee" x => 1]
+   ["tea" x => 2]
+   ["coke" x => 3])) ; too many clauses
+(typecheck-fail
+ (case (var "coffee" = (void) as (∨ ["coffee" Unit] ["tea" Unit]))
+   ["coffee" x => "1"]
+   ["tea" x => 2])) ; mismatched branch types
+(check-type
+ (case (var "coffee" = 1 as (∨ ["coffee" Int] ["tea" Unit]))
+   ["coffee" x => x]
+   ["tea" x => 2]) : Int ⇒ 1)
+(define-type-alias Drink (∨ ["coffee" Int] ["tea" Unit] ["coke" Bool]))
+(check-type ((λ ([x : Int]) (+ x x)) 10) : Int ⇒ 20)
+(check-type (λ ([x : Int]) (+ (+ x x) (+ x x))) : (→ Int Int))
+(check-type
+ (case ((λ ([d : Drink]) d)
+        (var "coffee" = 1 as (∨ ["coffee" Int] ["tea" Unit] ["coke" Bool])))
+   ["coffee" x => (+ (+ x x) (+ x x))]
+   ["tea" x => 2]
+   ["coke" y => 3])
+ : Int ⇒ 4)
+
+(check-type
+ (case ((λ ([d : Drink]) d) (var "coffee" = 1 as Drink))
+   ["coffee" x => (+ (+ x x) (+ x x))]
+   ["tea" x => 2]
+   ["coke" y => 3])
+ : Int ⇒ 4)
+
+;; previous tests: ------------------------------------------------------------
+;; tests for tuples -----------------------------------------------------------
+(check-type (tup 1 2 3) : (× Int Int Int))
+(check-type (tup 1 "1" #f +) : (× Int String Bool (→ Int Int Int)))
+(check-not-type (tup 1 "1" #f +) : (× Unit String Bool (→ Int Int Int)))
+(check-not-type (tup 1 "1" #f +) : (× Int Unit Bool (→ Int Int Int)))
+(check-not-type (tup 1 "1" #f +) : (× Int String Unit (→ Int Int Int)))
+(check-not-type (tup 1 "1" #f +) : (× Int String Bool (→ Int Int Unit)))
+
+(check-type (proj (tup 1 "2" #f) 0) : Int ⇒ 1)
+(check-type (proj (tup 1 "2" #f) 1) : String ⇒ "2")
+(check-type (proj (tup 1 "2" #f) 2) : Bool ⇒ #f)
+(typecheck-fail (proj (tup 1 "2" #f) 3)) ; index too large
+(typecheck-fail (proj 1 2)) ; not tuple
+
+;; ext-stlc.rkt tests ---------------------------------------------------------
+;; should still pass
+
+;; new literals and base types
+(check-type "one" : String) ; literal now supported
+(check-type #f : Bool) ; literal now supported
+
+(check-type (λ ([x : Bool]) x) : (→ Bool Bool)) ; Bool is now valid type
+
+;; Unit
+(check-type (void) : Unit)
+(check-type void : (→ Unit))
+(typecheck-fail ((λ ([x : Unit]) x) 2))
+(typecheck-fail ((λ ([x : Unit])) void))
+(check-type ((λ ([x : Unit]) x) (void)) : Unit)
+
+;; begin
+(typecheck-fail (begin))
+(check-type (begin 1) : Int)
+(typecheck-fail (begin 1 2 3))
+(check-type (begin (void) 1) : Int ⇒ 1)
+
+;;ascription
+(typecheck-fail (ann 1 : Bool))
+(check-type (ann 1 : Int) : Int ⇒ 1)
+(check-type ((λ ([x : Int]) (ann x : Int)) 10) : Int ⇒ 10)
+
+; let
+(check-type (let () (+ 1 1)) : Int ⇒ 2)
+(check-type (let ([x 10]) (+ 1 2)) : Int)
+(typecheck-fail (let ([x #f]) (+ x 1)))
+(check-type (let ([x 10] [y 20]) ((λ ([z : Int] [a : Int]) (+ a z)) x y)) : Int ⇒ 30)
+(typecheck-fail (let ([x 10] [y (+ x 1)]) (+ x y))) ; unbound identifier
+
+(check-type (let* ([x 10] [y (+ x 1)]) (+ x y)) : Int ⇒ 21)
+(typecheck-fail (let* ([x #t] [y (+ x 1)]) 1))
+
+; letrec
+(typecheck-fail (letrec ([(x : Int) #f] [(y : Int) 1]) y))
+(typecheck-fail (letrec ([(y : Int) 1] [(x : Int) #f]) x))
+
+(check-type (letrec ([(x : Int) 1] [(y : Int) (+ x 1)]) (+ x y)) : Int ⇒ 3)
+
+;; recursive
+(check-type
+ (letrec ([(countdown : (→ Int String))
+           (λ ([i : Int])
+             (if (= i 0)
+                 "liftoff"
+                 (countdown (- i 1))))])
+   (countdown 10)) : String ⇒ "liftoff")
+
+;; mutually recursive
+(check-type
+ (letrec ([(is-even? : (→ Int Bool))
+           (λ ([n : Int])
+             (or (zero? n)
+                 (is-odd? (sub1 n))))]
+          [(is-odd? : (→ Int Bool))
+           (λ ([n : Int])
+             (and (not (zero? n))
+                  (is-even? (sub1 n))))])
+   (is-odd? 11)) : Bool ⇒ #t)
+
+;; tests from stlc+lit-tests.rkt --------------------------
+; most should pass, some failing may now pass due to added types/forms
+(check-type 1 : Int)
+;(check-not-type 1 : (Int → Int))
+;(typecheck-fail "one") ; literal now supported
+;(typecheck-fail #f) ; literal now supported
+(check-type (λ ([x : Int] [y : Int]) x) : (→ Int Int Int))
+(check-not-type (λ ([x : Int]) x) : Int)
+(check-type (λ ([x : Int]) x) : (→ Int Int))
+(check-type (λ ([f : (→ Int Int)]) 1) : (→ (→ Int Int) Int))
+(check-type ((λ ([x : Int]) x) 1) : Int ⇒ 1)
+(typecheck-fail ((λ ([x : Bool]) x) 1)) ; Bool now valid type, but arg has wrong type
+;(typecheck-fail (λ ([x : Bool]) x)) ; Bool is now valid type
+(typecheck-fail (λ ([f : Int]) (f 1 2))) ; applying f with non-fn type
+(check-type (λ ([f : (→ Int Int Int)] [x : Int] [y : Int]) (f x y))
+            : (→ (→ Int Int Int) Int Int Int))
+(check-type ((λ ([f : (→ Int Int Int)] [x : Int] [y : Int]) (f x y)) + 1 2) : Int ⇒ 3)
+(typecheck-fail (+ 1 (λ ([x : Int]) x))) ; adding non-Int
+(typecheck-fail (λ ([x : (→ Int Int)]) (+ x x))) ; x should be Int
+(typecheck-fail ((λ ([x : Int] [y : Int]) y) 1)) ; wrong number of args
+(check-type ((λ ([x : Int]) (+ x x)) 10) : Int ⇒ 20)
+

tapl/typecheck.rkt

@@ -90,11 +90,25 @@
        #:with (x ...) #'(b.x ...)
        #:with (τ ...) #'(b.τ ...)
        #:with
-       (lam xs+ (lr-stxs+vs1 stxs1 vs1 (lr-stxs+vs2 stxs2 vs2 e+)))
+       ;; if e is (begin e1 ...), (e1 ...) will be spliced into expanded λ
+       ;; (and begin will be dropped), so must handle that 
+       (lam xs+ (lr-stxs+vs1 stxs1 vs1 (lr-stxs+vs2 stxs2 vs2 e_body+ ... e+)))
        (expand/df
         #`(λ (x ...)
             (let-syntax ([x (make-rename-transformer (⊢ #'x #'τ))] ...) #,e)))
-       (list #'xs+ #'e+ (typeof #'e+))]
+;       #:with tmp
+;       (expand/df
+;        #`(λ (x ...)
+;            (let-syntax ([x (make-rename-transformer (⊢ #'x #'τ))] ...) #,e)))
+;       #:when (printf "~a\n" (syntax->datum #'tmp))
+;       #:with (lam xs+ (lr-stxs+vs1 stxs1 vs1 (lr-stxs+vs2 stxs2 vs2 e+))) #'tmp
+
+       ;; if e is (begin ...), types (ie syntax properties) of all begins
+       ;; will be accumulated on e+, so only get the first type
+       #:with τ_e (if (null? (syntax->list #'(e_body+ ...)))
+                      (typeof #'e+)
+                      (stx-car (typeof #'e+)))
+       (list #'xs+ #'(begin e_body+ ... e+) #'τ_e)]
       [([x τ] ...) (infer/type-ctxt+erase #'([x : τ] ...) e)]))
   ; all xs are bound in the same scope
   (define (infers/type-ctxt+erase ctxt es)