From 1694f95eee8b7bf7081986c1ae9621a3c5c8de86 Mon Sep 17 00:00:00 2001
From: Elliot Glaysher <elliot@tlon.io>
Date: Wed, 2 May 2018 14:47:24 -0700
Subject: [PATCH] Implement +slit. Tests both the success and error cases.

---
 gen/ford-turbo.hoon | 106 ++++++++++++++++++++++++++++++++++++++++++++
 lib/ford-turbo.hoon |  26 ++++++++++-
 2 files changed, 130 insertions(+), 2 deletions(-)

diff --git a/gen/ford-turbo.hoon b/gen/ford-turbo.hoon
index a85c66574..fc422bb5a 100644
--- a/gen/ford-turbo.hoon
+++ b/gen/ford-turbo.hoon
@@ -28,6 +28,8 @@
   test-live-triangle
   test-live-and-pinned-triangle
   test-slim
+  test-slit
+  test-slit-error
   test-ride
   test-ride-scry-succeed
   test-ride-scry-fail
@@ -1045,6 +1047,110 @@
     (expect-ford-empty ford ~nul)
   ==
 ::
+++  test-slit
+  ~&  %test-slit
+  ::
+  =/  gate=vase    (ride %noun '|=(a=@ud ["one" a])')
+  =/  sample=vase  !>(42)
+  ::
+  =/  ford  *ford-turbo
+  =^  results1  ford
+    %-  test-ford-call-with-comparator  :*
+      ford
+      now=~1234.5.6
+      scry=scry-is-forbidden
+      ::
+      call-args=[duct=~[/slit] type=~ %make ~nul [%slit gate sample]]
+      ::
+      ^=  comparator
+        |=  moves=(list move:ford-turbo)
+        ^-  tang
+        ::
+        ?>  =(1 (lent moves))
+        ?>  ?=(^ moves)
+        ?>  ?=([* %give %made @da %complete %success %slit *] i.moves)
+        ::  we are expecting a type, and all we can do is ensure it nests in
+        ::  the right type
+        ::
+        =/  expected-type=type  -:!>([*tape *@ud])
+        =/  actual-type=type    |7:i.moves
+        %-  expect-eq  !>
+        :-  (~(nest ut actual-type) | expected-type)
+        &
+    ==
+  ::
+  =^  results2  ford
+    %-  test-ford-call  :*
+      ford
+      now=~1234.5.7
+      scry=scry-is-forbidden
+      ::
+      call-args=[duct=~[/slit] type=~ %kill ~nul]
+      ::
+      moves=~
+    ==
+  ::
+  ;:  weld
+    results1
+    results2
+    (expect-ford-empty ford ~nul)
+  ==
+::
+++  test-slit-error
+  ~&  %test-slit-error
+  ::
+  =/  gate=vase    (ride %noun '|=(a=@ud ["one" a])')
+  =/  sample=vase  !>("a tape instead of @ud")
+  ::
+  =/  ford  *ford-turbo
+  =^  results1  ford
+    %-  test-ford-call-with-comparator  :*
+      ford
+      now=~1234.5.6
+      scry=scry-is-forbidden
+      ::
+      call-args=[duct=~[/slit] type=~ %make ~nul [%slit gate sample]]
+      ::
+      ^=  comparator
+        |=  moves=(list move:ford-turbo)
+        ^-  tang
+        ::
+        ?>  =(1 (lent moves))
+        ?>  ?=(^ moves)
+        ?>  ?=([* %give %made @da %complete %error *] i.moves)
+        ::  ignore last message; contains source positions in the stack trace
+        ::
+        =/  messages=tang  (scag 4 `tang`|6:i.moves)
+        ::
+        %-  expect-eq  !>
+        :_  messages
+        :~  [%palm ["." "-" "" ""] [%leaf "have"] [%leaf "\"\""] ~]
+            :~  %palm  ["." "-" "" ""]
+                [%leaf "want"]
+                [%palm ["/" "" "" ""] [%leaf "a"] [%leaf "@ud"] ~]
+            ==
+            [%leaf "%slit failed: "]
+            [%leaf "nest-fail"]
+        ==
+    ==
+  ::
+  =^  results2  ford
+    %-  test-ford-call  :*
+      ford
+      now=~1234.5.7
+      scry=scry-is-forbidden
+      ::
+      call-args=[duct=~[/slit] type=~ %kill ~nul]
+      ::
+      moves=~
+    ==
+  ::
+  ;:  weld
+    results1
+    results2
+    (expect-ford-empty ford ~nul)
+  ==
+::
 ++  test-ride
   ~&  %test-ride
   ::
diff --git a/lib/ford-turbo.hoon b/lib/ford-turbo.hoon
index 94eddc5be..7c024f048 100644
--- a/lib/ford-turbo.hoon
+++ b/lib/ford-turbo.hoon
@@ -2470,9 +2470,9 @@
             %reef  !!
             %ride  (ride [formula subject]:schematic.build)
             %same  (same schematic.schematic.build)
-            %slit  !!
-            %slim  (slim [subject-type formula]:schematic.build)
             %scry  (scry resource.schematic.build)
+            %slim  (slim [subject-type formula]:schematic.build)
+            %slit  (slit [gate sample]:schematic.build)
             %vale  !!
             %volt  !!
         ==
@@ -2717,6 +2717,28 @@
           accessed-builds
           |
       ==
+    ::
+    ++  slit
+      |=  [gate=vase sample=vase]
+      ^-  build-receipt
+      ::
+      =/  product=(each type tang)
+        (mule |.((^slit p.gate p.sample)))
+      ::
+      :*  build
+          ?-  -.product
+            %|  :*  %build-result   %error
+                    :*  (~(dunk ut p.sample) %have)
+                        (~(dunk ut (~(peek ut p.gate) %free 6)) %want)
+                        leaf+"%slit failed: "
+                        p.product
+                    ==
+                ==
+            %&  [%build-result %success %slit p.product]
+          ==
+          accessed-builds
+          |
+      ==
     ::  |utilities:make: helper arms
     ::
     ::+|  utilities