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1 files changed, 52 insertions, 0 deletions

diff --git a/Language.hs b/Language.hs
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index 0000000..e16cf7c
--- /dev/null
+++ b/Language.hs
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+{-# LANGUAGE GADTs #-}
+
+{-| This module is intended to be imported qualified, perhaps as @L@. -}
+module Language where
+
+import AST
+import Sink
+
+
+map :: Exp env (a -> b) -> Exp env (Array sh a) -> Exp env (Array sh b)
+map f e =
+    let ty@(TArray sht _) = typeof e
+        sht' = shapeTypeType sht
+    in Let e
+           (Build sht (Shape (Var ty Zero))
+                      (Lam sht'
+                         (App (sinkExp2 f)
+                              (Index (Var ty (Succ Zero))
+                                     (Var sht' Zero)))))
+
+sum :: Exp env (Array (Int, ()) Double) -> Exp env Double
+sum e =
+    let ty@(TArray sht _) = typeof e
+    in Let e
+           (Ifold sht
+                  (Lam (TPair TDouble (TPair TInt TNil))
+                       (App (Const CAddF) (Pair
+                          (Fst (Var (TPair TDouble (TPair TInt TNil)) Zero))
+                          (Index (Var ty (Succ Zero)) (Snd (Var (TPair TDouble (TPair TInt TNil)) Zero))))))
+                  (Lit (LDouble 0))
+                  (Shape (Var ty Zero)))
+
+-- | The two input arrays are assumed to be the same size.
+zip :: Exp env (Array sh a) -> Exp env (Array sh b) -> Exp env (Array sh (a, b))
+zip a b =
+    let tarr@(TArray sht _) = typeof a
+        idxt = shapeTypeType sht
+    in Let a
+           (Build sht
+                  (Shape (Var tarr Zero))
+                  (Lam idxt
+                     (Pair (Index (Var tarr (Succ Zero)) (Var idxt Zero))
+                           (Index (sinkExp2 b) (Var idxt Zero)))))
+
+oneHot :: ShapeType sh -> Exp env sh -> Exp env sh -> Exp env (Array sh Double)
+oneHot sht sh idx =
+    let idxt = shapeTypeType sht
+    in Build sht sh
+             (Lam idxt
+                (Cond (App (Const (CEq idxt)) (Pair (Var idxt Zero) (sinkExp1 idx)))
+                      (Lit (LDouble 1))
+                      (Lit (LDouble 0))))