From 81ab073acf484dda7c9a7f3febb26ee3e93de21a Mon Sep 17 00:00:00 2001
From: Steven Troxler <stroxler@fb.com>
Date: Tue, 18 May 2021 11:46:33 -0700
Subject: [PATCH] Move Candidate to Ranking/Types.hs

Summary:
In my opinion putting `Candidate` into the core `Types.hs`
is a mistake - it's used exclusively in the ranking stage, so cluttering
the core tokenizing and recursive parsing / value resolution logic in
`Duckling.Types` with this irrelevant datatype makes things less clear
than if we keep it in the `Ranking` modules.

Reviewed By: chessai

Differential Revision: D28462902

fbshipit-source-id: cd4bb88c4a16945265e8f21c8808b06ae3383559
---
 Duckling/Ranking/Types.hs | 48 +++++++++++++++++++++++++++++++++++++++
 Duckling/Types.hs         | 37 ------------------------------
 2 files changed, 48 insertions(+), 37 deletions(-)

diff --git a/Duckling/Ranking/Types.hs b/Duckling/Ranking/Types.hs
index 87ee22f0..ebc5d96c 100644
--- a/Duckling/Ranking/Types.hs
+++ b/Duckling/Ranking/Types.hs
@@ -18,12 +18,20 @@ module Duckling.Ranking.Types
   , Classifier(..)
   , Classifiers
   , ClassData(..)
+  , Candidate(..)
 
   , infinity
   ) where
 import Data.HashMap.Strict (HashMap)
 import Data.Text (Text)
 import Prelude
+import Duckling.Types
+  ( Node(..)
+  , Range(..)
+  , ResolvedToken(..)
+  , Token(..)
+  , isDimension
+  )
 
 -- -----------------------------------------------------------------
 -- Aliases
@@ -55,3 +63,43 @@ data ClassData = ClassData
 
 infinity :: Double
 infinity = 1 / 0
+
+-- -----------------------------------------------------------------
+-- Candidate
+
+-- |A Candidate represents a potential match going into the ranker
+data Candidate = Candidate
+    ResolvedToken -- ^ The actual resolved token we are considering
+    Double -- ^ naive Bayes log-likelihood - sum of LL of all rules used
+    Bool -- ^ Does the ResolvedToken's dimension match the caller's request?
+  deriving (Eq, Show)
+
+instance Ord Candidate where
+  compare (Candidate Resolved{range = Range s1 e1, node = Node{token = Token d1 _}} score1 t1)
+          (Candidate Resolved{range = Range s2 e2, node = Node{token = tok2}} score2 t2)
+    | isDimension d1 tok2 = case starts of
+        EQ -> case ends of
+          EQ -> compare score1 score2
+          z -> z
+        LT -> case ends of
+          LT -> EQ
+          _ -> GT
+        GT -> case ends of
+          GT -> EQ
+          _ -> LT
+    | t1 == t2 = compRange
+    | t1 && compRange == GT = GT
+    | t2 && compRange == LT = LT
+    | otherwise = EQ
+      where
+        starts = compare s1 s2
+        ends = compare e1 e2
+        -- a > b if a recovers b
+        compRange = case starts of
+          EQ -> ends
+          LT -> case ends of
+            LT -> EQ
+            _  -> GT
+          GT -> case ends of
+            GT -> EQ
+            _  -> LT
diff --git a/Duckling/Types.hs b/Duckling/Types.hs
index 1750326f..5300acd4 100644
--- a/Duckling/Types.hs
+++ b/Duckling/Types.hs
@@ -253,43 +253,6 @@ instance Ord ResolvedToken where
       z  -> z
 
 
--- |A Candidate represents a potential match going into the ranker
-data Candidate = Candidate
-    ResolvedToken -- ^ The actual resolved token we are considering
-    Double -- ^ naive Bayes log-likelihood - sum of LL of all rules used
-    Bool -- ^ Does the ResolvedToken's dimension match the caller's request?
-  deriving (Eq, Show)
-
-instance Ord Candidate where
-  compare (Candidate Resolved{range = Range s1 e1, node = Node{token = Token d1 _}} score1 t1)
-          (Candidate Resolved{range = Range s2 e2, node = Node{token = tok2}} score2 t2)
-    | isDimension d1 tok2 = case starts of
-        EQ -> case ends of
-          EQ -> compare score1 score2
-          z -> z
-        LT -> case ends of
-          LT -> EQ
-          _ -> GT
-        GT -> case ends of
-          GT -> EQ
-          _ -> LT
-    | t1 == t2 = compRange
-    | t1 && compRange == GT = GT
-    | t2 && compRange == LT = LT
-    | otherwise = EQ
-      where
-        starts = compare s1 s2
-        ends = compare e1 e2
-        -- a > b if a recovers b
-        compRange = case starts of
-          EQ -> ends
-          LT -> case ends of
-            LT -> EQ
-            _  -> GT
-          GT -> case ends of
-            GT -> EQ
-            _  -> LT
-
 data Range = Range Int Int
   deriving (Eq, Ord, Generic, Hashable, Show, NFData)