From 69df6eeef0278b98f930e39d88efae9e3d6bd5d5 Mon Sep 17 00:00:00 2001
From: "William J. Bowman" <wjb@williamjbowman.com>
Date: Wed, 23 Mar 2016 18:32:34 -0400
Subject: [PATCH] Converted to new eliminator; all tests pass

---
 cur-lib/cur/curnel/redex-lang.rkt       | 17 +++---
 cur-lib/cur/olly.rkt                    | 14 ++++-
 cur-lib/cur/stdlib/prop.rkt             | 11 ++--
 cur-lib/cur/stdlib/sugar.rkt            | 75 +++++++++++++++++++++----
 cur-lib/info.rkt                        |  2 +-
 cur-test/cur/tests/olly.rkt             |  7 ++-
 cur-test/cur/tests/stdlib/list.rkt      | 10 ++--
 cur-test/cur/tests/stdlib/prop.rkt      | 10 ++--
 cur-test/cur/tests/stdlib/typeclass.rkt |  4 +-
 cur-test/info.rkt                       |  2 +-
 10 files changed, 107 insertions(+), 45 deletions(-)

diff --git a/cur-lib/cur/curnel/redex-lang.rkt b/cur-lib/cur/curnel/redex-lang.rkt
index 34dbcd7..36ce469 100644
--- a/cur-lib/cur/curnel/redex-lang.rkt
+++ b/cur-lib/cur/curnel/redex-lang.rkt
@@ -2,7 +2,7 @@
 ;; This module just provide module language sugar over the redex model.
 
 (require
-  "redex-core.rkt"
+  (except-in "redex-core.rkt" apply)
   redex/reduction-semantics
   racket/provide-syntax
   (for-syntax
@@ -11,7 +11,7 @@
     racket/syntax
     (except-in racket/provide-transform export)
     racket/require-transform
-    "redex-core.rkt"
+    (except-in "redex-core.rkt" apply)
     redex/reduction-semantics))
 (provide
   ;; Basic syntax
@@ -177,10 +177,11 @@
                     [e (parameterize ([gamma (extend-Γ/term gamma x t)])
                          (cur->datum #'e))])
                (term (,(syntax->datum #'b) (,x : ,t) ,e)))]
-            [(elim t1 t2)
-             (let* ([t1 (cur->datum #'t1)]
-                    [t2 (cur->datum #'t2)])
-               (term (elim ,t1 ,t2)))]
+            [(elim D motive (i ...) (m ...) d)
+             (term (elim ,(cur->datum #'D) ,(cur->datum #'motive)
+                         ,(map cur->datum (syntax->list #'(i ...)))
+                         ,(map cur->datum (syntax->list #'(m ...)))
+                         ,(cur->datum #'d)))]
             [(#%app e1 e2)
              (term (,(cur->datum #'e1) ,(cur->datum #'e2)))]))))
     (unless (or (inner-expand?) (type-infer/term reified-term))
@@ -446,9 +447,9 @@
 
 (define-syntax (dep-elim syn)
   (syntax-parse syn
-    [(_ D:id T)
+    [(_ D:id motive (i ...) (m ...) e)
      (syntax->curnel-syntax
-       (quasisyntax/loc syn (elim D T)))]))
+       (quasisyntax/loc syn (elim D motive (i ...) (m ...) e)))]))
 
 (define-syntax-rule (dep-void) (void))
 
diff --git a/cur-lib/cur/olly.rkt b/cur-lib/cur/olly.rkt
index ff4fe25..5db151b 100644
--- a/cur-lib/cur/olly.rkt
+++ b/cur-lib/cur/olly.rkt
@@ -95,8 +95,18 @@
                                      (cur->coq #'t))]))))
                "")]
             [(Type i) "Type"]
-            [(real-elim var t)
-             (format "~a_rect" (cur->coq #'var))]
+            [(real-elim var:id motive (i ...) (m ...) d)
+             (format
+              "(~a_rect ~a~a~a ~a)"
+              (cur->coq #'var)
+              (cur->coq #'motive)
+              (for/fold ([strs ""])
+                        ([m (syntax->list #'(m ...))])
+                (format "~a ~a" strs (cur->coq m)))
+              (for/fold ([strs ""])
+                        ([i (syntax->list #'(i ...))])
+                (format "~a ~a" strs (cur->coq i)))
+              (cur->coq #'d))]
             [(real-app e1 e2)
              (format "(~a ~a)" (cur->coq #'e1) (cur->coq #'e2))]
             [e:id (sanitize-id (format "~a" (syntax->datum #'e)))])))
diff --git a/cur-lib/cur/stdlib/prop.rkt b/cur-lib/cur/stdlib/prop.rkt
index a61bc52..3c3a191 100644
--- a/cur-lib/cur/stdlib/prop.rkt
+++ b/cur-lib/cur/stdlib/prop.rkt
@@ -71,11 +71,12 @@
 (define proof:A-or-A
   (lambda (A : Type) (c : (Or A A))
     ;; TODO: What should the motive be?
-    (elim Or Type (lambda (A : Type) (B : Type) (c : (Or A B)) A)
-      (lambda (A : Type) (B : Type) (a : A) a)
-      ;; TODO: How do we know B is A?
-      (lambda (A : Type) (B : Type) (b : B) b)
-      A A c)))
+    (elim Or (lambda (A : Type) (B : Type) (c : (Or A B)) A)
+          (A A)
+          ((lambda (A : Type) (B : Type) (a : A) a)
+           ;; TODO: How do we know B is A?
+           (lambda (A : Type) (B : Type) (b : B) b))
+          c)))
 
 (qed thm:A-or-A proof:A-or-A)
 |#
diff --git a/cur-lib/cur/stdlib/sugar.rkt b/cur-lib/cur/stdlib/sugar.rkt
index 71654b5..fb7ba99 100644
--- a/cur-lib/cur/stdlib/sugar.rkt
+++ b/cur-lib/cur/stdlib/sugar.rkt
@@ -12,7 +12,6 @@
   #%app
   define
   :
-  elim
   define-type
   match
   recur
@@ -29,7 +28,6 @@
 
 (require
   (only-in "../main.rkt"
-    [elim real-elim]
     [#%app real-app]
     [λ real-lambda]
     [Π real-Π]
@@ -163,8 +161,67 @@
      (quasisyntax/loc syn
        (real-define id body))]))
 
-(define-syntax-rule (elim t1 t2 e ...)
-  ((real-elim t1 t2) e ...))
+#|
+(begin-for-syntax
+  (define (type->telescope syn)
+    (syntax-parse (cur-expand syn)
+      #:literals (real-Π)
+      #:datum-literals (:)
+      [(real-Π (x:id : t) body)
+       (cons #'(x : t) (type->telescope #'body))]
+      [_ '()]))
+
+  (define (type->body syn)
+    (syntax-parse syn
+      #:literals (real-Π)
+      #:datum-literals (:)
+      [(real-Π (x:id : t) body)
+       (type->body #'body)]
+      [e #'e]))
+
+  (define (constructor-indices D syn)
+    (let loop ([syn syn]
+               [args '()])
+      (syntax-parse (cur-expand syn)
+        #:literals (real-app)
+        [D:id args]
+        [(real-app e1 e2)
+         (loop #'e1 (cons #'e2 args))])))
+
+  (define (inductive-index-telescope D)
+    (type->telescope (cur-type-infer D)))
+
+  (define (inductive-method-telescope D motive)
+    (for/list ([syn (cur-constructor-map D)])
+      (with-syntax ([(c : t) syn]
+                    [name (gensym (format-symbol "~a-~a" #'c 'method))]
+                    [((arg : arg-type) ...) (type->telescope #'t)]
+                    [((rarg : rarg-type) ...) (constructor-recursive-args D #'((arg : arg-type) ...))]
+                    [((ih : ih-type) ...) (constructor-inductive-hypotheses #'((rarg : rarg-type) ...) motive)]
+                    [(iarg ...) (constructor-indices D (type->body #'t))]
+                    )
+        #`(name : (forall (arg : arg-type) ...
+                          (ih : ih-type) ...
+                          (motive iarg ...)))))))
+
+(define-syntax (elim syn)
+  (syntax-parse syn
+    [(elim D:id U e ...)
+     (with-syntax ([((x : t) ...) (inductive-index-telescope #'D)]
+                   [motive (gensym 'motive)]
+                   [y (gensym 'y)]
+                   [disc (gensym 'disc)]
+                   [((method : method-type) ...) (inductive-method-telescope #'D #'motive)])
+       #`((lambda
+            (motive : (forall (x : t) ... (y : (D x ...)) U))
+            (method : ) ...
+            (x : t) ...
+            (disc : (D x ...)) ...
+            (real-elim D motive (x ...) (method ...) disc))
+          e ...)
+       )
+     ]))
+|#
 
 ;; Quite fragie to give a syntactic treatment of pattern matching -> eliminator. Replace with "Elimination with a Motive"
 (begin-for-syntax
@@ -366,15 +423,9 @@
      (quasisyntax/loc syn
        (elim
         D.inductive-name
-        #,(or
-           (cur-type-infer (attribute return-type))
-           (raise-syntax-error
-            'match
-            "Could not infer type of motive. Sorry, you'll have to use elim."
-            syn))
         motive
-        c.method ...
-        #,@(attribute D.indices)
+        #,(attribute D.indices)
+        (c.method ...)
         d))]))
 
 (begin-for-syntax
diff --git a/cur-lib/info.rkt b/cur-lib/info.rkt
index 916ccf0..0369661 100644
--- a/cur-lib/info.rkt
+++ b/cur-lib/info.rkt
@@ -3,5 +3,5 @@
 (define deps '("base" ("redex-lib" #:version "1.11")))
 (define build-deps '())
 (define pkg-desc "implementation (no documentation, tests) part of \"cur\".")
-(define version "0.3")
+(define version "0.4")
 (define pkg-authors '(wilbowma))
diff --git a/cur-test/cur/tests/olly.rkt b/cur-test/cur/tests/olly.rkt
index a2cda7b..e40c5cd 100644
--- a/cur-test/cur/tests/olly.rkt
+++ b/cur-test/cur/tests/olly.rkt
@@ -41,11 +41,12 @@
      "\\| T-Bla : \\(forall g : gamma, \\(forall e : term, \\(forall t : type, \\(\\(\\(meow g\\) e\\) t\\)\\)\\)\\)\\."
      (second (string-split t "\n"))))
   (let ([t (cur->coq
-            #'(elim nat Type (lambda (x : nat) nat) z
-                    (lambda (x : nat) (ih-x : nat) ih-x)
+            #'(elim nat (lambda (x : nat) nat)
+                    ()
+                    (z (lambda (x : nat) (ih-x : nat) ih-x))
                     e))])
     (check-regexp-match
-     "\\(\\(\\(\\(nat_rect \\(fun x : nat => nat\\)\\) z\\) \\(fun x : nat => \\(fun ih_x : nat => ih_x\\)\\)\\) e\\)"
+     "\\(nat_rect \\(fun x : nat => nat\\) z \\(fun x : nat => \\(fun ih_x : nat => ih_x\\)\\) e\\)"
      t))
   (check-regexp-match
    "Definition thm_plus_commutes := \\(forall n : nat, \\(forall m : nat, \\(\\(\\(== nat\\) \\(\\(plus n\\) m\\)\\) \\(\\(plus m\\) n\\)\\)\\)\\).\n"
diff --git a/cur-test/cur/tests/stdlib/list.rkt b/cur-test/cur/tests/stdlib/list.rkt
index afda5a8..f560ece 100644
--- a/cur-test/cur/tests/stdlib/list.rkt
+++ b/cur-test/cur/tests/stdlib/list.rkt
@@ -32,11 +32,11 @@
  (:: (lambda (A : Type) (n : Nat) (none A)) (forall (A : Type) (-> Nat (Maybe A)))))
 (check-equal?
  (void)
- (:: (elim List Type (lambda (A : Type) (ls : (List A)) Nat)
-          (lambda (A : Type) z)
-          (lambda (A : Type) (a : A) (ls : (List A)) (ih : Nat)
-                   z)
-          Bool
+ (:: (elim List (lambda (A : Type) (ls : (List A)) Nat)
+           (Bool)
+          ((lambda (A : Type) z)
+           (lambda (A : Type) (a : A) (ls : (List A)) (ih : Nat)
+                   z))
           (nil Bool))
     Nat))
 
diff --git a/cur-test/cur/tests/stdlib/prop.rkt b/cur-test/cur/tests/stdlib/prop.rkt
index ec90b0c..0d8222e 100644
--- a/cur-test/cur/tests/stdlib/prop.rkt
+++ b/cur-test/cur/tests/stdlib/prop.rkt
@@ -11,11 +11,11 @@
 (:: pf:proj1 thm:proj1)
 (:: pf:proj2 thm:proj2)
 (check-equal?
- (elim == Type (λ (A : Type) (x : A) (y : A) (p : (== A x y)) Nat)
-       (λ (A : Type) (x : A) z)
-       Bool
-       true
-       true
+ (elim == (λ (A : Type) (x : A) (y : A) (p : (== A x y)) Nat)
+       (Bool
+        true
+        true)
+       ((λ (A : Type) (x : A) z))
        (refl Bool true))
  z)
 
diff --git a/cur-test/cur/tests/stdlib/typeclass.rkt b/cur-test/cur/tests/stdlib/typeclass.rkt
index 9f6ce6c..fb8bb27 100644
--- a/cur-test/cur/tests/stdlib/typeclass.rkt
+++ b/cur-test/cur/tests/stdlib/typeclass.rkt
@@ -11,9 +11,7 @@
            (equal? : (forall (a : A) (b : A) Bool)))
 (impl (Eqv Bool)
       (define (equal? (a : Bool) (b : Bool))
-        (if a
-            (if b true false)
-            (if b false true))))
+        (if a b (not b))))
 (impl (Eqv Nat)
       (define equal? nat-equal?))
 (check-equal?
diff --git a/cur-test/info.rkt b/cur-test/info.rkt
index 37c408b..bc46632 100644
--- a/cur-test/info.rkt
+++ b/cur-test/info.rkt
@@ -1,7 +1,7 @@
 #lang info
 (define collection 'multi)
 (define deps '())
-(define build-deps '("base" "rackunit-lib" ("cur-lib" #:version "0.2") "sweet-exp"))
+(define build-deps '("base" "rackunit-lib" ("cur-lib" #:version "0.4") "sweet-exp"))
 (define update-implies '("cur-lib"))
 (define pkg-desc "Tests for \"cur\".")
 (define pkg-authors '(wilbowma))