From 2605ead9095e3812cedd539af8a7a9b7f195675c Mon Sep 17 00:00:00 2001
From: Mitchell Rosen <mitchellwrosen@gmail.com>
Date: Tue, 10 Sep 2019 19:55:49 -0400
Subject: [PATCH] some work on improving tuple type printing

---
 client-src/Ucb/Main/View.elm      |  2 +-
 client-src/Ucb/Main/View/Type.elm | 54 +++++++++++++++++++------------
 client-src/Unison/Reference.elm   | 20 ++++++++++++
 client-src/Unison/Type.elm        | 49 ++++++++++++++++++++++++++++
 4 files changed, 104 insertions(+), 21 deletions(-)

diff --git a/client-src/Ucb/Main/View.elm b/client-src/Ucb/Main/View.elm
index d3015e4..45f0dc9 100644
--- a/client-src/Ucb/Main/View.elm
+++ b/client-src/Ucb/Main/View.elm
@@ -213,7 +213,7 @@ viewBranches view =
                     )
 
         -- Should we show this branch?
-        -- Yes if:
+        -- Yes if, after applying the search filter,
         -- * It contains any types
         -- * It contains any non-constructor terms
         shouldBeVisible :
diff --git a/client-src/Ucb/Main/View/Type.elm b/client-src/Ucb/Main/View/Type.elm
index 148e9e3..e11455d 100644
--- a/client-src/Ucb/Main/View/Type.elm
+++ b/client-src/Ucb/Main/View/Type.elm
@@ -42,26 +42,40 @@ viewType view p ty0 =
                 )
 
         TypeTm (TypeApp ty1 ty2) ->
-            case ty1.out of
-                TypeTm (TypeRef (Builtin "Sequence")) ->
-                    row
-                        []
-                        [ text "[", viewType view 0 ty2, text "]" ]
-
-                _ ->
-                    case typeUnApps ty0 of
-                        Nothing ->
-                            impossible "viewType: unApps returned Nothing"
-
-                        Just ( f, xs ) ->
-                            ppParen (p >= 10)
-                                (row
-                                    []
-                                    [ viewType view 9 f
-                                    , text " "
-                                    , ppSpaced (List.map (viewType view 10) xs)
-                                    ]
-                                )
+            if typeIsSequenceRef ty1 then
+                row
+                    []
+                    [ text "[", viewType view 0 ty2, text "]" ]
+
+            else if typeIsPairRef ty1 then
+                let
+                    tys : List (Type Symbol)
+                    tys =
+                        typeUnTuple ty2
+                in
+                -- Print a horrible looking monster because Ian is
+                -- working on a better type printer.
+                row
+                    []
+                    [ text "(TUPLE "
+                    , row [] (List.map (viewType view 10) tys)
+                    , text ")"
+                    ]
+
+            else
+                case typeUnApps ty0 of
+                    Nothing ->
+                        impossible "viewType: unApps returned Nothing"
+
+                    Just ( f, xs ) ->
+                        ppParen (p >= 10)
+                            (row
+                                []
+                                [ viewType view 9 f
+                                , text " "
+                                , ppSpaced (List.map (viewType view 10) xs)
+                                ]
+                            )
 
         TypeTm (TypeForall _) ->
             let
diff --git a/client-src/Unison/Reference.elm b/client-src/Unison/Reference.elm
index dd5287f..bbd30b1 100644
--- a/client-src/Unison/Reference.elm
+++ b/client-src/Unison/Reference.elm
@@ -4,8 +4,10 @@ module Unison.Reference exposing
     , idEquality
     , idHashing
     , idToString
+    , pairReference
     , referenceEquality
     , referenceHashing
+    , unitReference
     )
 
 import Misc exposing (tumble)
@@ -92,3 +94,21 @@ idToString { hash, pos, size } =
             ++ String.fromInt pos
             ++ String.fromChar 'c'
             ++ String.fromInt size
+
+
+pairReference : Reference
+pairReference =
+    Derived
+        { hash = "onbcm0qctbnuctpm57tkc5p16b8gfke8thjf19p4r4laokji0b606rd0frnhj103qb90lve3fohkoc1eda70491hot656s1m6kk3cn0"
+        , pos = 0
+        , size = 1
+        }
+
+
+unitReference : Reference
+unitReference =
+    Derived
+        { hash = "568rsi7o3ghq8mmbea2sf8msdk20ohasob5s2rvjtqg2lr0vs39l1hm98urrjemsr3vo3fa52pibqu0maluq7g8sfg3h5f5re6vitj8"
+        , pos = 0
+        , size = 1
+        }
diff --git a/client-src/Unison/Type.elm b/client-src/Unison/Type.elm
index 06a01fe..45df89b 100644
--- a/client-src/Unison/Type.elm
+++ b/client-src/Unison/Type.elm
@@ -225,3 +225,52 @@ typeUnForalls vars ty =
 
         _ ->
             ( List.reverse vars, ty )
+
+
+typeUnTuple :
+    Type var
+    -> List (Type var)
+typeUnTuple ty =
+    case ty.out of
+        TypeTm (TypeRef ref) ->
+            if ref == unitReference then
+                []
+
+            else
+                impossible "typeUnTuple: didn't end with ()?"
+
+        _ ->
+            case typeUnApps ty of
+                Just ( f, [ ty1, ty2 ] ) ->
+                    case f.out of
+                        TypeTm (TypeRef ref) ->
+                            if ref == pairReference then
+                                ty1 :: typeUnTuple ty2
+
+                            else
+                                impossible "typeUnTuple: not pair?"
+
+                        _ ->
+                            impossible "typeUnTuple: not pair?"
+
+                _ ->
+                    impossible "typeUnTuple: wat?"
+
+
+typeIsPairRef :
+    Type var
+    -> Bool
+typeIsPairRef ty =
+    ty.out == TypeTm (TypeRef pairReference)
+
+
+typeIsSequenceRef :
+    Type var
+    -> Bool
+typeIsSequenceRef ty =
+    case ty.out of
+        TypeTm (TypeRef (Builtin "Sequence")) ->
+            True
+
+        _ ->
+            False