From 79beb66a2a8c63ff0e41923927857acddae819d2 Mon Sep 17 00:00:00 2001
From: Jeroen Engels <jfm.engels@gmail.com>
Date: Mon, 24 Jun 2019 23:00:36 +0200
Subject: [PATCH] Make Rule type opaque

---
 src/Lint.elm      |  6 +++---
 src/Lint/Rule.elm | 54 +++++++++++++++++++++++++++++++++--------------
 2 files changed, 41 insertions(+), 19 deletions(-)

diff --git a/src/Lint.elm b/src/Lint.elm
index c97d7c51..3c7f689b 100644
--- a/src/Lint.elm
+++ b/src/Lint.elm
@@ -46,7 +46,7 @@ import Elm.Syntax.File exposing (File)
 import Elm.Syntax.Node exposing (Node)
 import Lint.Direction exposing (Direction)
 import Lint.Error as Error exposing (Error)
-import Lint.Rule exposing (Rule)
+import Lint.Rule as Rule exposing (Rule)
 import Lint.RuleError as RuleError exposing (RuleError)
 
 
@@ -83,8 +83,8 @@ lintSource rules source =
 
 lintSourceWithRule : File -> ( Severity, Rule ) -> List ( Severity, RuleError )
 lintSourceWithRule file ( severity, rule ) =
-    rule.analyze file
-        |> List.map (\error -> ( severity, RuleError.fromError rule.name error ))
+    Rule.analyzer rule file
+        |> List.map (\error -> ( severity, RuleError.fromError (Rule.name rule) error ))
 
 
 {-| Parse source code into a AST
diff --git a/src/Lint/Rule.elm b/src/Lint/Rule.elm
index 8e6ce0de..088f8ce3 100644
--- a/src/Lint/Rule.elm
+++ b/src/Lint/Rule.elm
@@ -3,6 +3,7 @@ module Lint.Rule exposing
     , newSchema, fromSchema
     , withSimpleModuleDefinitionVisitor, withSimpleImportVisitor, withSimpleExpressionVisitor, withSimpleDeclarationVisitor
     , withInitialContext, withModuleDefinitionVisitor, withImportVisitor, withExpressionVisitor, withDeclarationVisitor, withFinalEvaluation
+    , name, analyzer
     )
 
 {-| This module contains functions that are used for writing rules.
@@ -19,6 +20,11 @@ module Lint.Rule exposing
 @docs withSimpleModuleDefinitionVisitor, withSimpleImportVisitor, withSimpleExpressionVisitor, withSimpleDeclarationVisitor
 @docs withInitialContext, withModuleDefinitionVisitor, withImportVisitor, withExpressionVisitor, withDeclarationVisitor, withFinalEvaluation
 
+
+# ACCESS
+
+@docs name, analyzer
+
 -}
 
 import Elm.Syntax.Declaration exposing (Declaration)
@@ -35,10 +41,11 @@ import Lint.Internal.DeclarationVisitor as DeclarationVisitor
 
 {-| Shortcut to a lint rule
 -}
-type alias Rule =
-    { name : String
-    , analyze : File -> List Error
-    }
+type Rule
+    = Rule
+        { name : String
+        , analyzer : File -> List Error
+        }
 
 
 {-| Represents a `rule` that will be enforced.
@@ -76,9 +83,9 @@ type Schema context
 
 -}
 newSchema : String -> Schema ()
-newSchema name =
+newSchema name_ =
     Schema
-        { name = name
+        { name = name_
         , initialContext = ()
         , moduleDefinitionVisitor = \node context -> ( [], context )
         , importVisitor = \node context -> ( [], context )
@@ -90,16 +97,17 @@ newSchema name =
 
 fromSchema : Schema context -> Rule
 fromSchema (Schema schema) =
-    { name = schema.name
-    , analyze =
-        \file ->
-            schema.initialContext
-                |> schema.moduleDefinitionVisitor file.moduleDefinition
-                |> accumulateList schema.importVisitor file.imports
-                |> accumulateList (DeclarationVisitor.visit schema.declarationVisitor schema.expressionVisitor) file.declarations
-                |> makeFinalEvaluation schema.finalEvaluationFn
-                |> List.reverse
-    }
+    Rule
+        { name = schema.name
+        , analyzer =
+            \file ->
+                schema.initialContext
+                    |> schema.moduleDefinitionVisitor file.moduleDefinition
+                    |> accumulateList schema.importVisitor file.imports
+                    |> accumulateList (DeclarationVisitor.visit schema.declarationVisitor schema.expressionVisitor) file.declarations
+                    |> makeFinalEvaluation schema.finalEvaluationFn
+                    |> List.reverse
+        }
 
 
 {-| Concatenate the errors of the previous step and of the last step.
@@ -190,3 +198,17 @@ withDeclarationVisitor visitor (Schema schema) =
 withFinalEvaluation : (context -> List Error) -> Schema context -> Schema context
 withFinalEvaluation visitor (Schema schema) =
     Schema { schema | finalEvaluationFn = visitor }
+
+
+
+-- ACCESS
+
+
+name : Rule -> String
+name (Rule rule) =
+    rule.name
+
+
+analyzer : Rule -> (File -> List Error)
+analyzer (Rule rule) =
+    rule.analyzer