Add back --debug flag, only generate debugger in that case

builder/src/File/Args.hs

@@ -11,6 +11,7 @@ import qualified Elm.Compiler.Module as Module
 import qualified Elm.Project.Json as Project
 import qualified Elm.Project.Summary as Summary
 import qualified Reporting.Exit as Exit
+import qualified Reporting.Exit.Make as E
 import qualified Reporting.Task as Task
 
 
@@ -36,4 +37,4 @@ fromSummary (Summary.Summary _ project _ _ _) =
       return $ Pkg (Project.getExposed info)
 
     Project.App _ ->
-      Task.throw Exit.CannotMakeNothing
+      Task.throw (Exit.Make E.CannotMakeNothing)

builder/src/Generate/Output.hs

@@ -34,6 +34,7 @@ import qualified Generate.Functions as Functions
 import qualified Generate.Html as Html
 import qualified Generate.Nitpick as Nitpick
 import qualified Reporting.Exit as Exit
+import qualified Reporting.Exit.Make as E
 import qualified Reporting.Task as Task
 import qualified Stuff.Paths as Paths
 import Terminal.Args (Parser(..), suggestFiles)
@@ -61,6 +62,7 @@ generate options summary graph@(Crawl.Graph args _ _ _ _) =
       do  objectGraph <- organize summary graph
 
           case _mode options of
+            Obj.Debug -> return ()
             Obj.Dev -> return ()
             Obj.Prod -> noDebugUses summary objectGraph
 
@@ -163,7 +165,7 @@ noDebugUses (Summary.Summary _ project _ _ _) graph =
       return ()
 
     m:ms ->
-      Task.throw (Exit.CannotOptimizeDebug m ms)
+      Task.throw (Exit.Make (E.CannotOptimizeDebugValues m ms))
 
 
 noDebugUsesInPackage :: Summary.Summary -> Crawl.Result -> Task.Task ()

builder/src/Reporting/Exit.hs

@@ -21,6 +21,7 @@ import qualified Reporting.Exit.Deps as Deps
 import qualified Reporting.Exit.Diff as Diff
 import qualified Reporting.Exit.Help as Help
 import qualified Reporting.Exit.Http as Http
+import qualified Reporting.Exit.Make as Make
 import qualified Reporting.Exit.Publish as Publish
 
 
@@ -37,13 +38,12 @@ data Exit
   | Cycle [Module.Raw] -- TODO write docs to help with this scenario
   | Deps Deps.Exit
   | Diff Diff.Exit
+  | Make Make.Exit
   | Publish Publish.Exit
   | BadHttp String Http.Exit
 
   -- misc
   | NoSolution [Pkg.Name]
-  | CannotMakeNothing
-  | CannotOptimizeDebug Module.Raw [Module.Raw]
 
 
 
@@ -86,17 +86,17 @@ toReport exit =
             "Whatever your scenario, I hope you have a lovely time using Elm!"
         ]
 
-    Assets assetError ->
-      Asset.toReport assetError
+    Assets assetExit ->
+      Asset.toReport assetExit
 
-    Bump bumpError ->
-      Bump.toReport bumpError
+    Bump bumpExit ->
+      Bump.toReport bumpExit
 
     Compile e es ->
       Help.compilerReport e es
 
-    Crawl crawlError ->
-      Crawl.toReport crawlError
+    Crawl crawlExit ->
+      Crawl.toReport crawlExit
 
     Cycle names ->
       Help.report "IMPORT CYCLE" Nothing
@@ -107,17 +107,20 @@ toReport exit =
             ++ D.makeLink "import-cycles"
         ]
 
-    Deps depsError ->
-      Deps.toReport depsError
+    Deps depsExit ->
+      Deps.toReport depsExit
 
-    Diff commandsError ->
-      Diff.toReport commandsError
+    Diff commandsExit ->
+      Diff.toReport commandsExit
 
-    Publish publishError ->
-      Publish.toReport publishError
+    Make makeExit ->
+      Make.toReport makeExit
 
-    BadHttp url httpError ->
-      Http.toReport url httpError
+    Publish publishExit ->
+      Publish.toReport publishExit
+
+    BadHttp url httpExit ->
+      Http.toReport url httpExit
 
     NoSolution badPackages ->
       case badPackages of
@@ -148,36 +151,3 @@ toReport exit =
                 \ goals, etc. They face obstacles outside of their technical work you will never\
                 \ know about, so please assume the best and try to be patient and supportive!"
             ]
-
-    CannotMakeNothing ->
-      Help.report "NO INPUT" Nothing
-        "What should I make though? I need more information, like:"
-        [ D.vcat
-            [ D.indent 4 $ D.green "elm make MyThing.elm"
-            , D.indent 4 $ D.green "elm make This.elm That.elm"
-            ]
-        , D.reflow
-            "However many files you give, I will create one JS file out of them."
-        ]
-
-    CannotOptimizeDebug m ms ->
-      Help.report "DEBUG REMNANTS" Nothing
-      "There are uses of the `Debug` module in the following modules:"
-        [ D.indent 4 $ D.red $ D.vcat $ map (D.fromString . Module.nameToString) (m:ms)
-        , D.reflow "But the --optimize flag only works if all `Debug` functions are removed!"
-        , D.toSimpleNote $
-            "The issue is that --optimize strips out info needed by `Debug` functions.\
-            \ Here are two examples:"
-        , D.indent 4 $ D.reflow $
-            "(1) It shortens record field names. This makes the generated JavaScript is\
-            \ smaller, but `Debug.toString` cannot know the real field names anymore."
-        , D.indent 4 $ D.reflow $
-            "(2) Values like `type Height = Height Float` are unboxed. This reduces\
-            \ allocation, but it also means that `Debug.toString` cannot tell if it is\
-            \ looking at a `Height` or `Float` value."
-        , D.reflow $
-            "There are a few other cases like that, and it will be much worse once we start\
-            \ inlining code. That optimization could move `Debug.log` and `Debug.todo` calls,\
-            \ resulting in unpredictable behavior. I hope that clarifies why this restriction\
-            \ exists!"
-        ]

builder/src/Reporting/Exit/Make.hs

@@ -0,0 +1,75 @@
+{-# LANGUAGE OverloadedStrings #-}
+module Reporting.Exit.Make
+  ( Exit(..)
+  , toReport
+  )
+  where
+
+
+import qualified Elm.Compiler.Module as Module
+import qualified Reporting.Doc as D
+import qualified Reporting.Exit.Help as Help
+
+
+
+-- EXITS
+
+
+data Exit
+  = CannotMakeNothing
+  | CannotOptimizeDebugValues Module.Raw [Module.Raw]
+  | CannotOptimizeAndDebug
+
+
+
+-- TO REPORT
+
+
+toReport :: Exit -> Help.Report
+toReport exit =
+  case exit of
+    CannotMakeNothing ->
+      Help.report "NO INPUT" Nothing
+        "What should I make though? I need more information, like:"
+        [ D.vcat
+            [ D.indent 4 $ D.green "elm make MyThing.elm"
+            , D.indent 4 $ D.green "elm make This.elm That.elm"
+            ]
+        , D.reflow
+            "However many files you give, I will create one JS file out of them."
+        ]
+
+    CannotOptimizeDebugValues m ms ->
+      Help.report "DEBUG REMNANTS" Nothing
+        "There are uses of the `Debug` module in the following modules:"
+        [ D.indent 4 $ D.red $ D.vcat $ map (D.fromString . Module.nameToString) (m:ms)
+        , D.reflow "But the --optimize flag only works if all `Debug` functions are removed!"
+        , D.toSimpleNote $
+            "The issue is that --optimize strips out info needed by `Debug` functions.\
+            \ Here are two examples:"
+        , D.indent 4 $ D.reflow $
+            "(1) It shortens record field names. This makes the generated JavaScript is\
+            \ smaller, but `Debug.toString` cannot know the real field names anymore."
+        , D.indent 4 $ D.reflow $
+            "(2) Values like `type Height = Height Float` are unboxed. This reduces\
+            \ allocation, but it also means that `Debug.toString` cannot tell if it is\
+            \ looking at a `Height` or `Float` value."
+        , D.reflow $
+            "There are a few other cases like that, and it will be much worse once we start\
+            \ inlining code. That optimization could move `Debug.log` and `Debug.todo` calls,\
+            \ resulting in unpredictable behavior. I hope that clarifies why this restriction\
+            \ exists!"
+        ]
+
+    CannotOptimizeAndDebug ->
+      Help.docReport "CLASHING FLAGS" Nothing
+        ( D.fillSep
+            ["I","cannot","compile","with",D.red "--optimize","and"
+            ,D.red "--debug","at","the","same","time."
+            ]
+        )
+        [ D.reflow
+            "I need to take away information to optimize things, and I need to\
+            \ add information to add the debugger. It is impossible to do both\
+            \ at once, so pick just one of those flags."
+        ]

compiler/src/Generate/JavaScript.hs

@@ -36,7 +36,7 @@ import qualified Reporting.Doc as D
 -- GENERATE MAINS
 
 
-data Mode = Dev | Prod
+data Mode = Prod | Dev | Debug
 
 
 data Output
@@ -71,8 +71,11 @@ addMain mode graph home _ state =
 toRealMode :: Mode -> Name.Target -> Map.Map N.Name Int -> Name.Mode
 toRealMode mode target fields =
   case mode of
+    Debug ->
+      Name.Dev target Name.DebuggerOn
+
     Dev ->
-      Name.Dev target
+      Name.Dev target Name.DebuggerOff
 
     Prod ->
       Name.Prod target (Name.shortenFieldNames fields)
@@ -85,7 +88,7 @@ toRealMode mode target fields =
 generateForRepl :: Opt.Graph -> I.Interface -> ModuleName.Canonical -> N.Name -> B.Builder
 generateForRepl (Opt.Graph _ graph _) iface home name =
   let
-    mode = Name.Dev Name.Server
+    mode = Name.Dev Name.Server Name.DebuggerOff
     debugState = addGlobal mode graph emptyState (Opt.Global ModuleName.debug "toString")
     evalState = addGlobal mode graph debugState (Opt.Global home name)
   in
@@ -238,7 +241,7 @@ generateCycle mode (Opt.Global home _) cycle =
     Name.Prod _ _ ->
       block
 
-    Name.Dev _ ->
+    Name.Dev _ _ ->
       JS.Try block Name.dollar $ JS.Throw $ JS.String $
         "The following top-level definitions are causing infinite recursion:\\n"
         <> drawCycle (map fst cycle)
@@ -310,7 +313,7 @@ addChunk mode builder chunk =
 
     Opt.Debug ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           builder
 
         Name.Prod _ _ ->
@@ -318,7 +321,7 @@ addChunk mode builder chunk =
 
     Opt.Prod ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           "_UNUSED" <> builder
 
         Name.Prod _ _ ->
@@ -334,7 +337,7 @@ generateEnum mode (Opt.Global home name) ctorName index =
   let
     definition =
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           Expr.codeToExpr (Expr.generateCtor mode ctorName index 0)
 
         Name.Prod _ _ ->
@@ -352,7 +355,7 @@ generateBox mode (Opt.Global home name) ctorName =
   let
     definition =
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           Expr.codeToExpr (Expr.generateCtor mode ctorName Index.first 1)
 
         Name.Prod _ _ ->

compiler/src/Generate/JavaScript/Expression.hs

@@ -58,7 +58,7 @@ generate mode expression =
     Opt.Chr char ->
       JsExpr $
         case mode of
-          Name.Dev _ ->
+          Name.Dev _ _ ->
             JS.Call toChar [ JS.String (Text.encodeUtf8Builder char) ]
 
           Name.Prod _ _ ->
@@ -81,7 +81,7 @@ generate mode expression =
 
     Opt.VarEnum (Opt.Global home name) index ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JsExpr $ JS.Ref (Name.fromGlobal home name)
 
         Name.Prod _ _ ->
@@ -90,7 +90,7 @@ generate mode expression =
     Opt.VarBox (Opt.Global home name) ->
       JsExpr $ JS.Ref $
         case mode of
-          Name.Dev _  -> Name.fromGlobal home name
+          Name.Dev _ _ -> Name.fromGlobal home name
           Name.Prod _ _ -> Name.fromGlobal ModuleName.basics N.identity
 
     Opt.VarCycle home name ->
@@ -161,7 +161,7 @@ generate mode expression =
 
     Opt.Unit ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JsExpr $ JS.Ref (Name.fromKernel N.utils "Tuple0")
 
         Name.Prod _ _ ->
@@ -261,7 +261,7 @@ generateCtor mode name index arity =
 
     ctorTag =
       case mode of
-        Name.Dev _ -> JS.String (N.toBuilder name)
+        Name.Dev _ _ -> JS.String (N.toBuilder name)
         Name.Prod _ _ -> JS.Int (Index.toMachine index)
   in
   generateFunction argNames $ JsExpr $ JS.Object $
@@ -363,7 +363,7 @@ generateCall mode func args =
 
     Opt.VarBox _ ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           generateCallHelp mode func args
 
         Name.Prod _ _ ->
@@ -744,7 +744,7 @@ generatePath mode path =
 
     Opt.Unbox subPath ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JS.Access (generatePath mode subPath) (Name.fromIndex Index.first)
 
         Name.Prod _ _ ->
@@ -872,7 +872,7 @@ generateIfTest mode root (path, test) =
     DT.IsCtor name index _ _ ->
       strictEq (JS.Access value Name.dollar) $
         case mode of
-          Name.Dev _ -> JS.String (N.toBuilder name)
+          Name.Dev _ _ -> JS.String (N.toBuilder name)
           Name.Prod _ _ -> JS.Int (Index.toMachine index)
 
     DT.IsInt int ->
@@ -881,7 +881,7 @@ generateIfTest mode root (path, test) =
     DT.IsChr char ->
       strictEq (JS.String (Text.encodeUtf8Builder char)) $
         case mode of
-          Name.Dev _ -> JS.Call (JS.Access value (Name.fromLocal "valueOf")) []
+          Name.Dev _ _ -> JS.Call (JS.Access value (Name.fromLocal "valueOf")) []
           Name.Prod _ _ -> value
 
     DT.IsStr string ->
@@ -911,7 +911,7 @@ generateCaseValue mode test =
   case test of
     DT.IsCtor name index _ _ ->
       case mode of
-        Name.Dev _ -> JS.String (N.toBuilder name)
+        Name.Dev _ _ -> JS.String (N.toBuilder name)
         Name.Prod _ _ -> JS.Int (Index.toMachine index)
 
     DT.IsInt int ->
@@ -941,7 +941,7 @@ generateCaseTest mode root path exampleTest =
   case exampleTest of
     DT.IsCtor _ _ _ opts ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JS.Access value Name.dollar
 
         Name.Prod _ _ ->
@@ -963,7 +963,7 @@ generateCaseTest mode root path exampleTest =
 
     DT.IsChr _ ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JS.Call (JS.Access value (Name.fromLocal "valueOf")) []
 
         Name.Prod _ _ ->
@@ -991,7 +991,7 @@ pathToJsExpr mode root path =
 
     DT.Unbox subPath ->
       case mode of
-        Name.Dev _ ->
+        Name.Dev _ _ ->
           JS.Access (pathToJsExpr mode root subPath) (Name.fromIndex Index.first)
 
         Name.Prod _ _ ->
@@ -1031,8 +1031,13 @@ toDebugMetadata mode interfaces msgType =
     Name.Prod _ _ ->
       JS.Int 0
 
-    Name.Dev _ ->
-      JS.Json $ Encode.object $
-        [ ("versions", Encode.object [ ("elm", Pkg.encodeVersion Version.version) ])
-        , ("types", Type.encodeMetadata (Extract.fromMsg interfaces msgType))
-        ]
+    Name.Dev _ debugger ->
+      case debugger of
+        Name.DebuggerOff ->
+          JS.Int 0
+
+        Name.DebuggerOn ->
+          JS.Json $ Encode.object $
+            [ ("versions", Encode.object [ ("elm", Pkg.encodeVersion Version.version) ])
+            , ("types", Type.encodeMetadata (Extract.fromMsg interfaces msgType))
+            ]

compiler/src/Generate/JavaScript/Name.hs

@@ -4,6 +4,7 @@ module Generate.JavaScript.Name
   ( Name
   , Mode(..)
   , Target(..)
+  , Debugger(..)
   , isServer
   , toBuilder
   , fromIndex
@@ -53,13 +54,18 @@ newtype Name =
 
 
 data Mode
-  = Dev Target
+  = Dev Target Debugger
   | Prod Target ShortFieldNames
 
 
 data Target = Client | Server
 
 
+data Debugger
+  = DebuggerOn
+  | DebuggerOff
+
+
 type ShortFieldNames =
   Map.Map N.Name Name
 
@@ -67,7 +73,7 @@ type ShortFieldNames =
 isServer :: Mode -> Bool
 isServer mode =
   case mode of
-    Dev target -> isServerHelp target
+    Dev target _ -> isServerHelp target
     Prod target _ -> isServerHelp target
 
 
@@ -124,7 +130,7 @@ fromKernel home name =
 fromField :: Mode -> N.Name -> Name
 fromField mode name =
   case mode of
-    Dev _ ->
+    Dev _ _ ->
       Name (N.toBuilder name)
 
     Prod _ fields ->

elm.cabal

@@ -117,6 +117,7 @@ Executable elm
         Reporting.Exit.Diff,
         Reporting.Exit.Help,
         Reporting.Exit.Http,
+        Reporting.Exit.Make,
         Reporting.Exit.Publish,
         Reporting.Progress,
         Reporting.Progress.Bar,

ui/terminal/src/Main.hs

@@ -173,6 +173,7 @@ make =
 
     makeFlags =
       flags Make.Flags
+        |-- onOff "debug" "Turn on the time-travelling debugger. It allows you to rewind and replay events. The events can be imported/exported into a file, which makes for very precise bug reports!"
         |-- onOff "optimize" "Turn on optimizations to make code smaller and faster. For example, the compiler renames record fields to be as short as possible and unboxes values to reduce allocation."
         |-- flag "output" Output.output "Specify the name of the resulting JS file. For example --output=assets/elm.js to generate the JS at assets/elm.js or --output=/dev/null to generate no output at all!"
         |-- flag "report" Make.reportType "You can say --report=json to get error messages as JSON. This is only really useful if you are an editor plugin. Humans should avoid it!"

ui/terminal/src/Make.hs

@@ -14,7 +14,10 @@ import qualified System.FilePath as FP
 import qualified Elm.Compiler.Objects as Obj
 import qualified Elm.Project as Project
 import qualified Generate.Output as Output
+import qualified Reporting.Exit as Exit
+import qualified Reporting.Exit.Make as E
 import qualified Reporting.Task as Task
+import qualified Reporting.Progress as Progress
 import qualified Reporting.Progress.Json as Json
 import qualified Reporting.Progress.Terminal as Terminal
 import Terminal.Args (Parser(..), suggestFiles)
@@ -26,7 +29,8 @@ import Terminal.Args (Parser(..), suggestFiles)
 
 data Flags =
   Flags
-    { _optimize :: Bool
+    { _debug :: Bool
+    , _optimize :: Bool
     , _output :: Maybe Output.Output
     , _report :: Maybe ReportType
     , _docs :: Maybe FilePath
@@ -34,23 +38,29 @@ data Flags =
 
 
 run :: [FilePath] -> Flags -> IO ()
-run paths (Flags optimize output report docs) =
-  let
-    mode =
-      if optimize then Obj.Prod else Obj.Dev
-
-    outputOptions =
-      Output.Options mode Obj.Client output
-
-    makeReporter =
-      case report of
-        Nothing -> Terminal.create
-        Just Json -> return Json.reporter
-  in
-  do  reporter <- makeReporter
+run paths (Flags debug optimize output report docs) =
+  do  reporter <- toReporter report
       void $ Task.run reporter $
-        do  summary <- Project.getRoot
-            Project.compile outputOptions docs summary paths
+        do  mode <- toMode debug optimize
+            summary <- Project.getRoot
+            let options = Output.Options mode Obj.Client output
+            Project.compile options docs summary paths
+
+
+toMode :: Bool -> Bool -> Task.Task Obj.Mode
+toMode debug optimize =
+  case (debug, optimize) of
+    (True , True ) -> Task.throw $ Exit.Make E.CannotOptimizeAndDebug
+    (False, True ) -> return Obj.Prod
+    (False, False) -> return Obj.Dev
+    (True , False) -> return Obj.Debug
+
+
+toReporter :: Maybe ReportType -> IO Progress.Reporter
+toReporter report =
+  case report of
+    Nothing -> Terminal.create
+    Just Json -> return Json.reporter