Do not reparse source for every rule

example/Main.elm

@@ -23,7 +23,7 @@ import Lint.Rules.NoUselessPatternMatching
 import Lint.Rules.NoWarningComments
 import Lint.Rules.SimplifyPiping
 import Lint.Rules.SimplifyPropertyAccess
-import Lint.Types
+import Lint.Types exposing (LintRule, Severity(..))
 import Regex exposing (escape, regex)
 import Result
 
@@ -50,22 +50,22 @@ type Msg
     = Replace String
 
 
-rules : List Lint.Types.LintRule
-rules =
-    [ Lint.Rules.DefaultPatternPosition.rule { position = Lint.Rules.DefaultPatternPosition.Last }
-    , Lint.Rules.NoConstantCondition.rule
-    , Lint.Rules.NoDebug.rule
-    , Lint.Rules.NoDuplicateImports.rule
-    , Lint.Rules.NoExposingEverything.rule
-    , Lint.Rules.NoImportingEverything.rule
-    , Lint.Rules.NoNestedLet.rule
-    , Lint.Rules.NoUnannotatedFunction.rule
-    , Lint.Rules.NoUnusedVariables.rule
-    , Lint.Rules.NoUselessIf.rule
-    , Lint.Rules.NoUselessPatternMatching.rule
-    , Lint.Rules.NoWarningComments.rule
-    , Lint.Rules.SimplifyPiping.rule
-    , Lint.Rules.SimplifyPropertyAccess.rule
+config : List ( Severity, LintRule )
+config =
+    [ ( Critical, Lint.Rules.DefaultPatternPosition.rule { position = Lint.Rules.DefaultPatternPosition.Last } )
+    , ( Critical, Lint.Rules.NoConstantCondition.rule )
+    , ( Critical, Lint.Rules.NoDebug.rule )
+    , ( Critical, Lint.Rules.NoDuplicateImports.rule )
+    , ( Critical, Lint.Rules.NoExposingEverything.rule )
+    , ( Critical, Lint.Rules.NoImportingEverything.rule )
+    , ( Critical, Lint.Rules.NoNestedLet.rule )
+    , ( Critical, Lint.Rules.NoUnannotatedFunction.rule )
+    , ( Critical, Lint.Rules.NoUnusedVariables.rule )
+    , ( Critical, Lint.Rules.NoUselessIf.rule )
+    , ( Critical, Lint.Rules.NoUselessPatternMatching.rule )
+    , ( Warning, Lint.Rules.NoWarningComments.rule )
+    , ( Critical, Lint.Rules.SimplifyPiping.rule )
+    , ( Critical, Lint.Rules.SimplifyPropertyAccess.rule )
     ]
 
 
@@ -194,7 +194,7 @@ lint : String -> Html Msg
 lint source =
     let
         lintResult =
-            lintSource rules source
+            lintSource config source
 
         messages =
             case lintResult of
@@ -205,7 +205,7 @@ lint source =
                     if List.isEmpty errors then
                         [ "No errors." ]
                     else
-                        errors
+                        List.map (Tuple.second >> .message) errors
     in
         div []
             (List.map

src/Lint.elm

@@ -32,9 +32,9 @@ To run the rules on a source code and get a list of errors:
 
 import Ast
 import Ast.Expression exposing (Expression)
-import Ast.Statement
+import Ast.Statement exposing (Statement)
 import Combine
-import Lint.Types exposing (LintRule, LintResult, LintError, LintImplementation, LintRuleImplementation, Direction, Visitor, Severity, Severity(..))
+import Lint.Types exposing (LintRule, LintError, LintImplementation, LintRuleImplementation, Direction, Visitor, Severity, Severity(..))
 import Lint.Visitor exposing (transformStatementsIntoVisitors, expressionToVisitors)
 import Regex
 
@@ -49,22 +49,17 @@ lintSource rules source =
     source
         |> parseSource
         |> Result.map
-            (\_ ->
+            (\( _, _, statements ) ->
                 rules
                     |> List.concatMap
-                        (lintSourceWithRule source)
+                        (lintSourceWithRule statements)
             )
 
 
-
--- type alias Reporter a =  -> a
-
-
-lintSourceWithRule : String -> ( Severity, LintRule ) -> List ( Severity, LintError )
-lintSourceWithRule source ( severity, rule ) =
-    rule source
-        |> Result.map (List.map ((,) severity))
-        |> Result.withDefault []
+lintSourceWithRule : List Statement -> ( Severity, LintRule ) -> List ( Severity, LintError )
+lintSourceWithRule statements ( severity, rule ) =
+    rule statements
+        |> List.map ((,) severity)
 
 
 parseSource : String -> Result (List String) (Combine.ParseOk () (List Ast.Statement.Statement))
@@ -96,16 +91,11 @@ removeComments =
         , initialContext = Context
         }
 -}
-lint : String -> LintRuleImplementation context -> LintResult
-lint source rule =
-    source
-        |> parseSource
-        |> Result.map
-            (\( _, _, statements ) ->
+lint : List Statement -> LintRuleImplementation context -> List LintError
+lint statements rule =
     statements
         |> transformStatementsIntoVisitors
         |> lintWithVisitors rule
-            )
 
 
 {-| Visit an expression using a sub rule implementation. The use of this function is not encouraged, but it can make

src/Lint/Types.elm

@@ -120,7 +120,7 @@ type alias LintResult =
 {-| Shortcut to a lint rule
 -}
 type alias LintRule =
-    String -> LintResult
+    List Statement -> List LintError
 
 
 {-| Shorthand for a function that takes a rule's implementation, a context and returns ( List LintError, context ).