From be8ed14d609eae96444706bf9a52d2a0f1050cff Mon Sep 17 00:00:00 2001
From: Maryyam <niazim3@mcmaster.ca>
Date: Thu, 14 Jun 2018 16:57:30 -0400
Subject: [PATCH] Created isLabel and HasLabel classes (#643)

* created isLabel and HasLabel classes

* moved newly created classes to Classes file; created new file to avoid cyclic imports

* Renamed some files as suggested
---
 code/Language/Drasil/Classes.hs    | 10 ++++++++++
 code/Language/Drasil/Label.hs      | 15 +--------------
 code/Language/Drasil/Label/Core.hs | 15 +++++++++++++++
 code/drasil.cabal                  |  1 +
 4 files changed, 27 insertions(+), 14 deletions(-)
 create mode 100644 code/Language/Drasil/Label/Core.hs

diff --git a/code/Language/Drasil/Classes.hs b/code/Language/Drasil/Classes.hs
index 65db83ef3c..7b67b7b98a 100644
--- a/code/Language/Drasil/Classes.hs
+++ b/code/Language/Drasil/Classes.hs
@@ -11,6 +11,8 @@ module Language.Drasil.Classes (
   , HasSpace(typ)
   , HasUnitSymbol(usymb)
   , IsUnit
+  , HasLabel(getLabel)
+  , IsLabel
   , UnitEq(uniteq)
   , HasReference(getReferences)
   , CommonIdea(abrv)
@@ -27,6 +29,7 @@ import Language.Drasil.Space (Space)
 import Language.Drasil.UnitLang (USymb, UDefn)
 import Language.Drasil.Chunk.References (References)
 import Language.Drasil.UID (UID)
+import Language.Drasil.Label.Core (Label)
 import Language.Drasil.Chunk.Constrained.Core (Constraint)
 import Language.Drasil.Expr (Expr)
 import Language.Drasil.Chunk.Derivation
@@ -94,6 +97,13 @@ class Constrained c where
 class HasReasVal c where
   reasVal     :: Lens' c (Maybe Expr)
 
+-- | For those things which "have a label"
+class HasLabel c where
+  getLabel :: Lens' c Label
+
+-- IsLabel is associated with String rendering
+class (HasLabel u, HasUID u) => IsLabel u where
+
 -----------------------------------------------------
 -- Below are for units only
 -- | Some chunks store a unit symbol
diff --git a/code/Language/Drasil/Label.hs b/code/Language/Drasil/Label.hs
index c177101a60..7c665ed178 100644
--- a/code/Language/Drasil/Label.hs
+++ b/code/Language/Drasil/Label.hs
@@ -1,21 +1,9 @@
-{-# Language TemplateHaskell #-}
 module Language.Drasil.Label (Label) where
 
-import Control.Lens (makeLenses)
-import Language.Drasil.UID (UID)
+import Language.Drasil.Label.Core
 import Language.Drasil.Classes (HasUID(uid))
 import Data.Char (isAscii)
 
--- import reference address from Language.Drasil.References?
-data LblType = RefAdd String | MetaLink String | URI String
-
--- Used for referencing; has to be pure ASCII
-data Label = Lbl
-  { _uniqueID  :: UID --internal, unique
-  , lblType    :: LblType 
-  }
-makeLenses ''Label
-  
 instance HasUID Label where uid = uniqueID
 
 -- multiple mkLabel constructors for label creation
@@ -29,6 +17,5 @@ mkLabelML id ref = Lbl id (MetaLink $ ensureASCII ref)
 mkLabelURI :: String -> String -> Label
 mkLabelURI id ref = Lbl id (URI $ ensureASCII ref)
 
--- helpers
 ensureASCII :: String -> String
 ensureASCII s = map (\y -> if isAscii y then y else error "Label needs to be pure ASCII.") s
\ No newline at end of file
diff --git a/code/Language/Drasil/Label/Core.hs b/code/Language/Drasil/Label/Core.hs
new file mode 100644
index 0000000000..29154b5a94
--- /dev/null
+++ b/code/Language/Drasil/Label/Core.hs
@@ -0,0 +1,15 @@
+{-# Language TemplateHaskell #-}
+module Language.Drasil.Label.Core where
+
+import Control.Lens (makeLenses)
+import Language.Drasil.UID (UID)
+
+-- import reference address from Language.Drasil.References?
+data LblType = RefAdd String | MetaLink String | URI String
+
+-- Used for referencing; has to be pure ASCII
+data Label = Lbl
+  { _uniqueID  :: UID --internal, unique
+  , lblType    :: LblType 
+  }
+makeLenses ''Label
\ No newline at end of file
diff --git a/code/drasil.cabal b/code/drasil.cabal
index 86db516ba4..fc8284382f 100644
--- a/code/drasil.cabal
+++ b/code/drasil.cabal
@@ -41,6 +41,7 @@ library
     , Language.Drasil.Expr.Math
     , Language.Drasil.Expr.Precedence
     , Language.Drasil.Classes
+    , Language.Drasil.Label.Core
     , Language.Drasil.Label
     , Language.Drasil.Config
     , Language.Drasil.Document